Various populations with chronic conditions are at risk for decreased cognitive performance, making assessment of their cognition important. Formal mobile cognitive assessments measure cognitive performance with greater ecological validity than traditional laboratory-based testing but add to participant task demands. Given that responding to a survey is considered a cognitively demanding task itself, information that is passively collected as a by-product of ecological momentary assessment (EMA) may be a means through which people’s cognitive performance in their natural environment can be estimated when formal ambulatory cognitive assessment is not feasible. We specifically examined whether the item response times (RTs) to EMA questions  can serve as approximations of cognitive processing speed.This study aims to investigate whether the RTs from noncognitive EMA surveys can serve as approximate indicators of between-person (BP) differences and momentary within-person (WP) variability in cognitive processing speed.Data from a 2-week EMA study investigating the relationships among glucose, emotion, and functioning in adults with type 1 diabetes were analyzed. Validated mobile cognitive tests assessing processing speed (Symbol Search task) and sustained attention (Go-No Go task) were administered together with noncognitive EMA surveys 5 to 6 times per day via smartphones. Multilevel modeling was used to examine the reliability of EMA RTs, their convergent validity with the Symbol Search task, and their divergent validity with the Go-No Go task. Other tests of the validity of EMA RTs included the examination of their associations with age, depression, fatigue, and the time of day.P<.001). EMA RTs had significant BP associations with age (P<.001), as expected, but not with depression (P=.20) or average fatigue (P=.18). In WP analyses, the RTs to 16 slider items and all 22 EMA items (including the 16 slider items) had acceptable (>0.70) WP reliability. After correcting for unreliability in multilevel models, EMA RTs from most combinations of items showed moderate WP correlations with the Symbol Search task  and demonstrated theoretically expected relationships with momentary fatigue and the time of day. The associations between EMA RTs and the Symbol Search task were greater than those between EMA RTs and the Go-No Go task at both the BP and WP levels, providing evidence of divergent validity.Overall, in BP analyses, evidence was found supporting the reliability and convergent validity of EMA question RTs from even a single repeatedly administered EMA item as a measure of average processing speed. BP correlations between the Symbol Search task and EMA RTs ranged from 0.43 to 0.58  may be a method of approximating people’s average levels of and momentary fluctuations in processing speed without adding tasks beyond the survey questions. Various illnesses are risk factors for decreased cognitive performance, including type 1 diabetes (T1D), type 2 diabetes, depression, and cardiovascular disease , making Several behavioral health-focused EMA studies have used formal ambulatory cognitive tests in various populations, including individuals with T1D -13, breaCognitive performance may potentially be inferred from EMA survey paradata  and thus could be a means to approximate people’s momentary cognitive functioning in their natural environments without the time demand of additional formal cognitive testing. Paradata have been investigated as a means of approximating the cognitive aspects underlying survey responding in traditional (non-EMA) survey studies. For instance, a study examining survey response behaviors at older ages found that the time of survey initiation and time of survey completion were related to mild cognitive impairment . In anotThe purpose of this study was to investigate whether the RTs to noncognitive EMA questions  can serve as approximate indicators of person-level differences and momentary WP fluctuations in processing speed. Aside from individuals’ average processing speed (person-level differences), momentary fluctuations in processing speed may also be useful to assess via EMA survey paradata. For instance, intraindividual cognitive variability increases with age, even among those who remain cognitively healthy , and varWe capitalized on preexisting data from an EMA study in which adults with T1D completed 2 weeks of EMA surveys together with smartphone-based mobile processing speed and sustained attention tests . CognitiAs the primary test of convergent validity, we examined the associations between the RTs to different subsets of EMA items and the scores of mobile processing speed tests. We hypothesized that if EMA survey RTs captured processing speed, slower RTs would be associated with worse performance on the formal processing speed test, both at the between-person (BP) and WP levels.As secondary tests of convergent validity, we examined the associations between the RTs to different subsets of EMA items and depression symptoms, age, fatigue, and a diurnal cycle. In a review, individuals with major depression were found to have lower processing speed than controls , so we eTo assess divergent validity, we tested the association between EMA item RTs and sustained attention ability. We anticipated that if EMA RTs are indicators of processing speed, they would have stronger associations with processing speed than with sustained attention ability. Although both processing speed and sustained attention ability are fundamental cognitive skills, they are distinct aspects of cognitive performance that are measured using different tests ,35. For The goal of the EMA study from which data were analyzed was to investigate the relationships among momentary emotion, function, and glucose, the full methodology of which has been outlined previously . ParticiThe data collection procedures were approved by the University of Southern California institutional review board .RTs to the 22 noncognitive EMA survey items listed in Our primary set of noncognitive EMA survey RTs was the RTs to the 16 slider items, but other noncognitive EMA survey RT combinations were also examined. To compare the reliability and validity of EMA RTs across types of EMA items, we classified the items by response option type and further by item content domains, where possible, as presented in r=0.74 with its standard laboratory version [At the end of each EMA survey, participants were prompted to complete the Symbol Search task, a phone-based mobile processing speed test . This ta version . In this version , they weThe measures of fatigue, depression, age, and the time of day were also used for validity testing. The momentary fatigue item  was similar to that used in a previous EMA study . DepressMultilevel modeling was used to evaluate (1) the WP and BP reliability of EMA RTs, (2) WP and BP correlations of EMA RTs with the Symbol Search task , and (3) WP and BP associations of EMA RTs with other constructs . Analyses of reliability and convergent validity were conducted in a parallel fashion for EMA RTs and for the Symbol Search task. Thus, the results of the reliability and validity testing of EMA RTs could be directly compared with the findings from the Symbol Search analyses. For instance, the magnitude of the correlation between EMA RTs and fatigue can be compared with the size of the association between the Symbol Search task and fatigue.To examine the extent to which the characteristics of EMA items may impact the reliability and validity of EMA RTs, analyses were conducted using the RTs to all 22 EMA items, as well as using the RTs to subgroups of EMA items and the RTs to individual items. The groupings of item RTs were as presented in Both the BP and WP reliabilities of EMA RTs and the Symbol Search task were estimated. BP reliability describes the consistency of a person’s mean value across all measurement occasions of a given measure  . It can occasion)/(Var(WPoccasion) + Var/i) [occasion) is the variance within a person across different measurement occasions, Var is the variance of RTs across the EMA items administered within a given measurement occasion, and i is the number of EMA items. The variance components Var(WPoccasion) and Var [To estimate the WP reliabilities of the measures, we capitalized on the fact that the RTs from multiple EMA items  were available at each measurement occasion . WP reliability is the consistency of the mean RT across EMA items within a single measurement occasion. The formula is WP reliability = Var/i) , where VWPtrial)  were estAs the primary convergent validity test, the WP and BP correlations of EMA RTs with the Symbol Search task were examined using bivariate multilevel models, in which both measures were entered as bivariate  dependent variables. Specifically, 3-level models (items nested in measurement occasions nested in people) were specified, whereby the WP correlation was estimated at level 2 and the BP correlation was estimated at level 3. This had the advantage that the correlations at both levels were adjusted for the unreliability due to variance in RTs within measurement occasions (estimated at level 1). For exploratory purposes, 2-level models were also examined to allow for comparison with the results from the 3-level models. In these 2-level models, rather than estimating the variance in RTs within measurement occasions at level 1, we used the observed (manifest) average of RTs.plus  [MplusAutomation [Secondary convergent validity and divergent validity tests were conducted similarly with 3-level multilevel models. As fatigue ratings and Go-No Go (sustained attention ability) varied both within and between individuals, we estimated both between-individual and within-individual correlations of fatigue and Go-No Go with EMA RTs . For the BP variables age and depression, we estimated only BP correlations with EMA RTs . The diurnal cycle of EMA RTs was also examined to test whether the pattern was consistent with previous research on the diurnal cycle of cognitive performance. A multilevel cosinor model  was used Muthén)  with thetomation  in the stomation .The analyses were conducted on data from 198 participants . A totalThe reliabilities of the Symbol Search task and EMA RTs are listed in EMA RTs from the 16 slider items had a BP ICC of 0.56, which was lower than the BP Symbol Search ICC. With 3 measurement occasions, the BP reliability of EMA RTs from the 16 slider items increased to 0.79. The WP reliability of EMA RTs from the 16 slider items was 0.82, which was slightly higher than that of the Symbol Search task. The BP and WP reliability values of EMA RTs from all 22 EMA items were nearly identical to those from the 16 slider items.In terms of RTs from other sets of EMA items comprising 3 to 4 questions, BP ICCs ranged from 0.31 for the 3 multiple-choice items to 0.44 for the 4 positive affect slider items. With 3 measurement occasions, only the BP reliability of the RTs for the 3 multiple-choice items was notably <0.70, with a value of 0.57. WP reliability for the EMA RTs of the slider item subgroups ranged from 0.49 to 0.60. RTs for the 3 multiple-choice and 3 checkbox items had much lower WP reliabilities, with values of 0.08 and 0.22, respectively.BP reliabilities for the RTs to single EMA items are presented in Tables S1 and S2 in r=0.29 (P<.001) to r=0.40 (P<.001); multiple-choice items had a larger correlation with the Symbol Search task  or depression ratings (P=.20), contrary to our hypothesis ; and age was similarly correlated with EMA RTs, with magnitudes ranging from 0.47 to 0.54 (P<.001). Consistent with our hypothesis, EMA RTs were more highly correlated with the Symbol Search scores  than with the Go-No Go scores .At the BP level, neither the EMA RTs from different sets of items nor the Symbol Search task were significantly associated with average fatigue . Slower RTs for EMA items were similarly associated with greater momentary fatigue, and this relationship was significant for RTs from all sets of EMA items , except for those from multiple-choice items (P=.11). EMA RTs were again more highly correlated with the Symbol Search scores  than with the Go-No Go scores .At the WP level, the correlations were overall consistent with our hypotheses . Worse Sr=0.27 in a 2-level model vs r=0.35 in a 3-level model for the 16 EMA slider items). RTs from multiple-choice EMA items showed the biggest difference in WP correlation with the Symbol Search task when comparing 2-level and 3-level models (r=0.18 in a 2-level model vs r=0.58 in a 3-level model).Tables S4 and S5 in z scores , which translated to RT fluctuations of 0.34 × 2 = 0.68 SDs within a day, corresponding to a medium to large effect size [P<.001), meaning that RTs fluctuated by approximately 0.16 × 2 = 0.32 SDs (z scores) within a day, corresponding to a small effect size [The diurnal cycle of EMA RTs was examined and compared with that of the Symbol Search RTs. As shown in ect size . EMA RTsect size . DiurnalOverall, our results suggest that EMA RTs can serve as approximate indicators of both momentary and average processing speeds. The EMA RTs for the items analyzed in this study were better indicators of average, as compared with momentary, processing speed. A formal processing speed test (Symbol Search) and EMA RTs had correlations of approximately 0.5 at the BP level and 0.3 at the WP level. These correlation sizes may be acceptable in research contexts in which investigators do not have the resources for administering formal cognitive testing. Correlations of these magnitudes may be sufficient to detect strong associations with processing speed, although weaker associations may be missed. The findings of the reliability and validity tests are described in greater detail in the subsequent sections.Overall, EMA RTs showed acceptable reliability under conditions  typical of many EMA studies. Furthermore, BP reliability for EMA RTs were similar to that for Symbol Search RTs, and WP reliability for RTs to the 16 EMA slider items slightly exceeded that for the Symbol Search task.The BP reliability of EMA RTs from various item sets differed largely as a function of the number of EMA measurement occasions. With just 3 EMA measurement occasions, BP reliability was acceptable (approximately 0.70), except for RTs from the 3 multiple-choice and 3 checkbox items. The lower BP reliability in these item sets may have been due to their greater heterogeneity , leading to greater variability  in mean RTs. For single items, except for multiple-choice questions, the average RTs had a reliability of at least 0.70 with 7 EMA measurement occasions. This suggests that with a relatively small number of EMA measurement occasions, even RTs from single EMA items will likely have acceptable BP reliability. For 16 slider items, the completion of just 2 EMA surveys was sufficient to cross the threshold of 0.70 BP reliability, likely because it was a larger set of items that shared the same type of response options. With more than 16 items sharing similar response options, it would perhaps be possible to obtain a reliable assessment of EMA survey RTs from just 1 measurement occasion.In terms of the WP reliability of EMA RTs (consistency of RTs within a single EMA measurement occasion), the number of EMA questions and the type of response options appeared to be major contributing factors. The RTs to the 16 slider items had a WP reliability of 0.82, considerably higher than the WP reliability of the RTs to the item sets with only 3 or 4 items. These smaller item sets had reliability values between 0.08 and 0.60, limiting their precision for capturing WP changes in processing speed with 2-level (and not 3-level) modeling. Of the item sets with 3 or 4 items, the more homogenous sets (slider items by topic) had much greater WP reliability than the heterogeneous sets (multiple-choice and checkbox questions with differing numbers of response options). WP reliability improved after combining RTs from various slider items, suggesting that item content was not as important to reliability as the response option type. When considering RTs from the heterogeneous response option item sets, in addition to the 16 slider items, the WP reliability was similar to that found for the 16 slider items alone. Thus, for the WP reliability of EMA RTs, considering RTs from more items may not always be beneficial, specifically when the additional items have different response options.P=.18) or depression (P=.20). Significant BP correlations were found between age and both RTs to EMA items (P<.001) and the Symbol Search task (P<.001). Consistent with our hypothesis, EMA RTs had a greater BP association with the Symbol Search task than with the Go-No Go task. Overall, we interpret the BP correlations as being supportive of the validity of EMA item RTs as approximate measures of processing speed.Although some findings were contrary to our hypotheses , the results appeared overall supportive of the validity of EMA item RTs as an approximate measure of processing speed. In our primary convergent validity test at the BP level, EMA RTs had moderate to large correlations with the Symbol Search task, a magnitude expected if EMA RTs were indicators of processing speed. In terms of secondary convergent validity tests at the BP level, observed relationships with EMA RTs were sometimes contrary to our hypotheses but were typically very similar to the associations seen with the Symbol Search task. At the BP level, we hypothesized that slower EMA RTs would be associated with greater average fatigue and greater depressive symptoms. Neither of these relationships was confirmed. For fatigue, this may have been because previous research found associations between slower processing speed and chronic fatigue syndrome  , but theAt the BP level, higher sustained attention ability was correlated with greater processing speed as measured by the Symbol Search task and was generally weakly associated with EMA RTs. Interestingly, at the BP level, better sustained attention ability was associated with faster Symbol Search RTs but with slower EMA RTs for 4 of the 8 EMA RT item sets. We can only speculate why this might be the case. Perhaps participants with greater sustained attention ability were better able to process information quickly when they were explicitly instructed to respond as fast as possible (in the Symbol Search task), whereas they may have more deliberately read the EMA items and more carefully considered their responses, leading to slower RTs in EMA.At the WP level, the results were also overall supportive of the validity of EMA item RTs as measures of processing speed. Most importantly, moderate or larger correlations between different sets of EMA RTs and the Symbol Search task were observed. The diurnal cycle of EMA RTs roughly approximated the daily pattern for Symbol Search RTs. Slower EMA RTs were associated with greater fatigue for all item sets, except for multiple-choice questions. Notably, fatigue was associated with processing speed and EMA RTs at the WP level but not at the BP level. It is possible that participants in our sample did at times experience fatigue (within level) but not frequently enough that the average level of fatigue experienced was associated with decrements in processing speed on average (between level). Consistent with our hypothesis, EMA RTs had greater WP associations with the Symbol Search task than with the Go-No Go task.Although associations between EMA RTs and the Symbol Search task were observed, the relationships were not strong enough to argue that they provided identical measures. From the outset, we did not advocate for RTs of EMA items to serve as a replacement for formal cognitive testing; rather, we sought to examine whether they can serve as rough processing speed indicators when formal tests are not available. The tasks of completing a formal processing speed test and completing EMA items differ in several aspects. For instance, one common formal processing speed test is searching for a figure that matches a given image. In this task, RTs conceptually capture perceptual speed , a compoThe RTs to single EMA items appeared to lack WP validity, as evidenced by low WP correlations with the Symbol Search task, but they may have some degree of BP validity with sufficient EMA measurement occasions. With an average of 70 EMA surveys completed, the BP association between the RTs to single EMA items and RTs to the Symbol Search task ranged from 0.43 to 0.58. The results of reliability analyses suggested that slightly more than 7 EMAs may result in a BP reliability of at least 0.7, indicating that a relatively small number of EMA instances  is sufficient to recover high BP associations with the Symbol Search task.r=0.58) but also a WP reliability much lower than other item sets. Three-level modeling helped to compensate for this low reliability by removing the errors from item-level RT variance, and the result was a much higher correlation compared with when a 2-level model was used (r=0.18). The practical implication may be that EMA RTs with low WP reliability, such as those from a few multiple-choice items differing in content and the number of response options, would not be useful to model with the 2-level approach and requires 3-level modeling. However, with a greater number of parameters specified, 3-level versions of 2-level models require larger sample sizes.The RTs to the 3 multiple-choice items notably had the highest WP correlation with the Symbol Search task , where the activity was done (from 5 choices), and the perceived level of blood glucose (from 4 choices). In a future study, it may be useful to more formally investigate the extent to which item content and the number of response options in multiple-choice questions affect relationships with a formal processing speed test.The RTs from only a small subset of possible question types were investigated here. For multiple-choice and checkbox items, there were not enough items to investigate the effect of the number of response choices or the topics covered by these response option types. Although the effect of question topic did not appear to exert a large impact on EMA RTs for the slider items in this study, we cannot say whether the content of EMA items influences the reliability or validity of RTs to multiple-choice and checkbox items.Data from standard laboratory-administered cognitive assessments were not collected. Therefore, we could not examine the convergent validity of individual differences in EMA item RTs using a full-length laboratory assessment of processing speed. Although a previous study found a high correlation between standard laboratory and ambulatory assessments of processing speed , whetherr=0.99 (P<.001) at the BP level (level 3) and r=0.97 (P<.001) at the survey session level (level 2). The close correspondence between the 2 appeared to justify the use of mean RTs for accurate trials, instead of the median, to enable the modeling of the Symbol Search task at 3 levels.The recommended outcome measure for the Symbol Search task, the median reaction time in accurate trials , was notThis study was conducted with a sample of adults with T1D experiencing various stages of the COVID-19 pandemic, which may limit the generalizability of the results. For instance, study participants were more likely to complete EMA surveys at home during times of stricter social distancing requirements. The completion of EMA surveys at home may have less potential for exposure to environmental distractors, which may have reduced the variability in item RTs. As we only examined EMA RTs as processing speed indicators in adults with T1D, further research may be needed to investigate whether findings can be replicated in other populations. For instance, the causes of processing speed fluctuations are often chronic condition specific. In adults with T1D, acute hypoglycemia has been associated with decreased processing speed ,29. In aOverall, EMA RTs appeared to be reliable and valid indicators of average and momentary processing speeds. They were not correlated to the extent that EMA survey RTs can replace formal processing speed tests. Rather, EMA survey RTs may be serviceable as rough processing speed indicators when formal processing speed testing is not feasible and when the magnitude of associations with processing speed is large. The reliability and validity of EMA survey RTs as measures of processing speed differed according to the sets of items from which the RTs were extracted, implying that EMA items can potentially be intentionally crafted to have greater associations with processing speed. For instance, in a future study, factorial analyses or machine learning models could be used to identify the specific combinations of EMA items for which the pattern of RTs is the most predictive of scores from a formal processing speed test. Analysis of RTs from EMA items may be a method of assessing average and momentary processing speeds in people’s natural environments, which does not require participants to complete additional tasks beyond answering EMA survey questions. RTs to noncognitive EMA items may be important to facilitate research on the impacts of processing speed on daily functioning, especially for populations with chronic conditions.


It can be defined as the fabrication in morphology with the help of smart/intelligent materials like polymers that permit the final object to alter its properties, shape, or function in response to external stimuli such as heat, light, pH, and moisture. The applications of 4DP in biomedicines and healthcare are explored with a focus on tissue engineering, artificial organs, drug delivery, pharmaceutical and biomedical field, etc. In the medical treatments and pharmaceutical field 4DP is paving the way with unlimited potential applications; however, its mainstream use in healthcare and medical treatments is highly dependent on future developments and thorough research findings. Therefore, previous innovations with smart materials are likely to act as precursors of 4DP in many industries. This review highlights the most recent applications of 4DP technology and smart materials in biomedical and healthcare fields which can show a better perspective of 4DP applications in the future. However, in view of the existing limitations, major challenges of this technology must be addressed along with some suggestions for future research. We believe that the application of proper regulatory constraints with 4DP technology would pave the way for the next technological revolution in the biomedical and healthcare sectors. The term “4D Printing” (4DP) was coined firstly by Skylar Tibbits in 2014  Raviv D. Advance4DP is found to be the most remarkable transformation in the existing 3DP technique and is an exemplar of the additive manufacturing (AM) technique. 4DP is another smart technology to design flexible and dynamic structures and overcome the limitations of 3DP technology . It is cA research group at MIT first conceptualized the idea of the 4DP of objects . The newThere are three salient features of 4DP that must be satisfied. First is the “selection of composite material”  which should be responsive to external stimuli, when given. The second is the “external stimulus” which when added to the material makes the object animated. Last is the “time taken by the object to get stimulated” . TherefoThere are many advantages of 4DP technology such as it is highly cost-efficient, time-efficient, less error-prone, highly productive, and sensitive . There i4DP is highly dependent on five factors these are equipment/3D printers, stimulus-responsive material, stimuli, interaction mechanism, and the types of AM processes . The AM Generally, the materials used for 4DP are called smart or intelligent materials because these are capable to change their properties with time . FurtherMany recent studies have explored a nascent field that integrates therapeutics with 3D and 4D printing. As a result, many formulation concepts and pharmaceutical devices have emerged that can be printed and possibly tailored to an individual. Traditional production is being replaced by rapidly expanding 4DP technology in a wide range of industries that includes medical engineering, healthcare , automobIn medical devices and healthcare, a growing interest is seen in 4DP which explores a new arena of additive manufacturing research that has the potential to explore both 3DP and 4DP technologies. 4DP has a great advantage for diversified biomedical and healthcare applications, such as tissue engineering, bio-actuators, biosensors, and robotics . The medBiocompatibility is an important issue in the fabrication of Bio-Medical (BM) devices. Another issue of great importance is fabricating high-resolution structures that remain stable in their temporary as well as permanent spatial arrangements . Due to It is said that the 4DP technique works on 3DP fabricating materials made from intelligent materials which are able to fold/unfold themselves. The use of these smart materials can be divided into two mechanisms, i.e., bio-adhesion and encapsulation based on drug delivery. There is a great global concern among scientists about novel drug delivery approaches and 4DP has the potential to offer the new concept of fabrication. In the search for real medical applications, still, high-quality research is needed to apply the technology to consumable medications .An important application of 4D bio-printing is related to pharmaceuticals, bio-adhesion, and drug delivery systems where drugs or cells are encapsulated and then released under the influence of a particular stimulus . Effortsstimuli. When exposed to temperatures above 32°C according to the predetermined design, it spontaneously grips onto the tissue as soon as introduced into the body at room temperature  technique is used to design biosensors  previously. In recent years, implantable sensors have fetched revolutionary interest in healthcare that can provide continuous information for prolonged periods of time . A transA two-photon stereolithography approach has already been used to fabricate biosensors that are microcantilever-based, using polymers that are molecularly imprinted  and the Self-healing pipes and hydrogels, and removing construction errors are some of the important applications of 4DP smart materials that will do wonders in the upcoming time. These 4DP materials are also used as sensors and printed artificial organs . Cells aTo accomplish biological applications; 3DBP is applied for the substance transfer method to fabricate various living materials. Fully customized, complex structures can be printed by transforming elaborated medical images like X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans into 3D Computer-aided design (3D CAD) models for the printing apparatus . RecentlAs compared to conventional tissue engineering; bioprinting has many benefits and most importantly high precision in cell deposing, and fabrication of tissues with high quantities & formed of large tissue-engineered objects. Basically, 4DBP includes a biomaterial and the maturation of the 3DP skeleton using the biomaterial . Researc3DP has fetched considerable attention in the biomedical field and tissue engineering . Differein-situ unfolding of 4DBP scaffolds. In the presence of biological moieties, the self-folding process can be done in response to external stimuli . Recent work presented the application of shape-memory scaffolds in the delivery of functional tissues that is minimally invasive . Another stimuli . To perf stimuli . Similar stimuli . The pot stimuli .The fundamental difference between 3DP and 4DP technologies occurs in the materials that are used to fabricate certain objects. Alternatively, 4DP has added mathematics, stimulus, and interaction parts using smart material, which is entirely different from 3DP. The requirements of dynamic structures and their relevant application such as soft grippers , self-asAlthough, 3DBP has tremendous growth due to multiple applications and advantages  but, it has certain limitations also. 3DPB considers only the original state of the printed structure and considers it to be lifeless . Still, The lack of special software for 4DP is another significant limitation because most of the available software (such as design and slicing software) has been prepared for use in 3DP. To meet the requirements of 4DP, more powerful software has to be introduced. There are limitations in selecting smart materials that are used in the biological field like tissue engineering and tissue regeneration because of the limited number of intelligent materials that react to specific stimuli. Limited material availability, slow and inaccurate actuation, etc. are other challenges that need to be addressed. Though, 4DP technology has already proved its efficiency in multiple fields including medical engineering and with the development of inexpensive, high-accuracy printing devices, and most significantly, with the finding of novel smart bio-materials it is predicted to gain its top prospect soon.Technological advancements have brought revolutions in diagnostic and treatment methods. The growing need for advanced technology boosts investments in this field and is further propelling market growth. Consequently, the 4DP healthcare market is growing continuously and it is expected to reach USD 32.8 million in 2028 and CAGR will reach upto 26.7%. Different government and semi-government agencies are working and promoting this smart technology in various developed and developing countries. 4DP has wide applications in different sectors like automobiles, aviation, textiles , manufacA driving factor for the use of 4DP in the healthcare field is the growing demand for organ transplants which requires functional implants in the area of tissue engineering and biomaterials. The enormous growth of 4DP is also due to its involvement in complicated cancer chemotherapies and surgical techniques due to the lesser use of surgical techniques . Also, t4DP has grown tremendously since its inception and has proved its influence in different manufacturing & industrial sectors along with healthcare. Despite being a novel technology, 4DP has potential opportunities that are acknowledged by several experts in the field. 4DBP technology has gained lots of attention in biomedical and healthcare applications due to the development of stimulus-responsive biomaterials and tissue regeneration. Further advancement of 4DP will explore the tremendous applications in the biomedical field and would meet the upgraded medical requirements. The latest and highly effective methods of incorporating electronics into smart structures may result in the betterment of novel intelligent devices. Conclusively, 4DBP has an encouraging and hopeful future as a potential technology to copy traditional cellular structures. Therefore, it is expected that 4DP will certainly bring a bright future and revolution into different manufacturing and design industries and a paradigm shift to the plethora of undiscovered bigness that will make our future bright, smarter, and much more convenient. At the same time, more studies are required to resolve the existing challenges before 4DP serves as a powerful and a sustainable technique on a global level.


The Brugada syndrome is an uncommon inherited condition associated with increased risk of ventricular tachyarrhythmias and sudden cardiac death. Different triggers including fever are well known to precipitate the Brugada pattern on electrocardiogram. We report a patient who presents with syncope, two days after the first dose of the BNT162b2 vaccine due to fever-related unmasking of Brugada syndrome. Therefo244 years old Indian gentleman without significant medical history presented after an episode of syncope. The history was taken from a friend who witnessed the syncope episode at work. The patient suddenly lost consciousness then developed generalized tonic clonic (GTC) seizure with tongue bite which lasted for around 10 minutes. The patient had post-ictal tiredness with no bladder or bowel incontinence. There was no history of any identifiable precipitants. The patient regained consciousness after 1–2 minutes. He reported a daylong of subjective fever, which he attributed to the coronavirus disease-2019 (COVID-19) vaccine. He received the first dose of the BNT162b2 vaccine 48 hours before the presentation. He denied recent travel or any sick contacts. The patient had a similar episode of syncope approximately 3 years ago, in which he had a brief syncopal attack lasted for few seconds and he didn't seek any medical advice and did not receive any medications; the patient denied any family history of sudden cardiac death.In the emergency department, the patient was afebrile, alert and fully conscious, with stable vital signs so no medications were administered. Blood tests and CT head were ordered in view of new seizure. Suddenly, he collapsed and had ventricular tachycardia followed by ventricular fibrillation which required cardiopulmonary resuscitation (CPR) and defibrillation for 3 minutes. The patient denied having any chest pain at any stage during his presentation. After the CPR, a 12 lead ECG showed normal sinus rhythm with Brugada pattern in V1–V2, with S1Q3T3 with minimal ST elevation in the inferior leads . His labFollow-up visit after 3 months, the patient was in good condition with no more attacks. Vital signs were normal. ECG was repeated and showed sinus rhythm with Q3 and T wave inversion on V1 . No geneWritten consent was obtained prior to the writing of this report.3The COVID-19 outbreak has been announced as a pandemic by the World Health Organization (WHO) in 2020 . COVID-1Since the beginning of COVID-19 pandemic, several effective vaccines were developed for SARS-CoV-2, yet there are still many questions regarding their safety. One of the most common reported side effects was fever, and it was mainly observed after the second dose of BNT162b2 mRNA Covid-19 Vaccine within the first one to two days after vaccination . A recenConsidering the acute history, the short interval between the administration of vaccination and the presentation of the patient with cardiac arrest, and the exclusion of other common causes; BNT162b2 vaccine-induced fever which unmasked Brugada syndrome is the most likely precipitant factor in our patient.A similar case was reported by Okawa et a, suggested that ECG screening is necessary before the initial COVID-19 vaccination to find any asymptomatic unknown Brugada syndrome, to reduce the risk of sudden cardiac arrest in such patients . Our cas4We would like to highlight the importance of performing additional precautions and preventive measures like ECG monitoring and antipyretic treatment with Covid 19 vaccination, as it may reduce the cardiac arrhythmias that might be developed due to fever, in patients with underlying conduction disorders such as Brugada syndrome.All authors listed have significantly contributed to the investigation, development and writing of this article.Data will be made available on request.No additional information is available for this paper.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


The current SARS cov 2 virus disease pandemic presents a threatening physical danger as well as its impact on mental health. It seems important to screen any patient who has experienced covid 19 for its psychological impact.Therefore the aim of our study was to highlight the impact of COVID-19 infection on mental health by screening them for depressionThis is a cross-sectional, single-center study, conducted at the Sahloul Emergency Department, over a period of 5 months (January to May 2021). Patients are collected from a database of ouremergencydepartment COVID-19 unit.We included patients whose age is greater than or equal to 18 years old; who has been infected with SARS-COV-2 according to the results of the PCR test. All patients lost to follow-up, refusing to participate in this study, having a psychiatric illness or having taken a psychotropic medication before randomization or non-cooperating  were excluded.A telephone follow-up was done after 30 days from admission to calculate the HAMILTON score after a positif HAD D scale.200 patients were included. For the 20 patients (10%) with depressive symptomatology (doubtful and certain) according to the HAD D scale, their responses to the Hamilton scale were analysed in order to determine the severity of the depressive symptomatology. Note that 30% of patients had mild to moderate signs of depression and 70% had severe depression.The majority of patients in whom the presence of depressive symptoms was noted had an average age of 40 years; those who presented with severe depression had an average age of 51.3 years with a female majority of 72%. No difference was noted in relation to pathological history, half had been hospitalized for treatment of COVID-19(57%). Patients with severe depression symptom resolution lasted an average of 14 days.According to the results of this study, interventions may be carried out to minimize the pandemic’s negative psychological consequences.None Declared


Arabidopsis thaliana and focuses on dissecting the mode of inheritance and combining ability of plasticity in the context of plant breeding. We created a full diallel cross using 12 A. thaliana accessions displaying different temperature-mediated flower size plasticities, scored as the fold change between two temperatures. Griffing’s analysis of variance in flower size plasticity indicated that non-additive genetic action shapes this trait and pointed at challenges and opportunities when breeding for reduced plasticity. Our findings provide an outlook of flower size plasticity that is important for developing resilient crops for future climates.Phenotypic plasticity is a heritable trait that provides sessile organisms a strategy to rapidly mitigate negative effects of environmental change. Yet, we have little understanding of the mode of inheritance and genetic architecture of plasticity in different focal traits relevant to agricultural applications. This study builds on our recent discovery of genes controlling temperature-mediated flower size plasticity in  Any deviation from the MPV confined in the range of parental plasticities would indicate dominance, and values outside of this range denote overdominance. Characterizing GCA, SCA, and the mode of inheritance for plasticity can be readily addressed by having accesses to MAF2-5 gene cluster is associated with flower size plasticity to temperature based on genome-wide association with 290 A. thaliana accessions  hybrids were genotyped to ensure heterozygosity . These two sets represent the biological replicates grown in two separate trials. To record FDs for each of the individual plants, at least six open flowers from the primary inflorescence were collected, resulting in at least 12 replicates for every genotype. To minimize the technical variation, flowers were only taken after the eighth flower had opened and were always harvested in the morning after the lights had been on for at least 3 hr. Flowers were placed on a 96-well plate containing 1–2% agarose and macrographs were taken. FDs as two diagonals were measured from macrographs, using imageJ software, as an average of all measurements. To quantify plasticity of flower size to temperature, the FC between 23 and 17°C was calculated. For each genotype, four independent FCs were calculated by dividing each of the two mean FDs of the two biological replicates at 23°C with each of the two mean FDs of the two biological replicates at 17°C.Flower diameter (FD) was used a proxy for flower size . Flower sizes for all crosses were scored at 23 and at 17°C with two biological replicates . In addition to these two accessions, Donana-0  also had FC close to one, implying lack of plasticity; in this accession, there was a significant but small difference between the mean values of flower sizes between 23 and 17°C . Hence, the most common mode of inheritance observed was additive inheritance, as the other 118 crosses did not show significantly different FC in comparison to their MPV.To characterize the most frequent mode of inheritance, we calculated the MPVs and investigated where the mean of temperature-mediated flower size plasticity of each cross is positioned with respect to the range of plasticities for the parents. By conducting one-sample Next, we investigated how many of the 14 non-additive cases were due to dominance or overdominance. We found that 11 out of the 14 hybrids only showed significant different FC from one of the parents and thereby exhibited full dominance . In all Altogether, these results demonstrate that in most cases the inheritance patterns of the temperature-mediated flower size plasticity were additive, allowing prediction from the phenotype of the parents. Nevertheless, in the rare case of non-additive inheritance, the increased plasticity alleles are dominantly inherited. The presence of non-additive inheritance cannot be captured with the most widely used methods used to predict the estimated breeding values in agriculture and could have dramatic effect on breeding in which the additive inheritance is preferred . From these, only two crosses (Lag1-2 × HKT2.4 and Mammo-2 × Xan-1) also showed non-additive inheritance in our previous analysis. This refers to the fact that SCA is a relative analysis in the context of the analysed population. The smallest negative SCA was observed for the Or-0 × Lag1-2 cross.A. thaliana  are known to induce response to an increase in temperature. We have recently investigates genetic basis of temperature-mediated flower size plasticity. In our recent wrok , using genome-wide analysis combined with characterization of mutant lines, we showed that temperature-mediated is associated with MAF2-5 locus on chromosome 5.This study builds on this discovery to further investigate the full potential of temperature-mediated flower size plasticity, especially in the context of plant breeding. To this end, we have made full diallel crosses among twelwe parents showing different flower size plasticities and assessed the heritability patterns of this focal trait. Our findings showed that:A. thaliana.- Overall the heritability of temperature-mediated flower size plasticity was moderate, but comparable to that of yield and fitness in - While majority of the first generation crosses showed additive inheritance, with only 11 out of 242 accessions that showed non-additive inheritance.- The non-additively inherited crosses all showed dominance towards plasticity increase.- Plasticity in heterozygous hybrids exhibited a larger range of values than in homozygous parents, but heterozygous plants did not show more plasticity than homozygous parents.To conclude, our findings indicate that although with high potential, breeding of plasticity is challenging due to non-additive inheritance and low heritability. Our results highlights the importance of the suitable genotypes to breeding for plasticity and profoundly increase understanding of the impact of temperature on phenotypic plasticity, and the challenges it imposes in plant species.Sincerely,Roosa Laitinen Comments to Author: This manuscript addresses the genetic basis of phenotypic plasticity. The phenotype studied is Arabidopsis flower size, which shows plasticity to ambient temperature. This study builds on a recent publication of a gene cluster associated with this plasticity. Therefore, the description of the genetic inheritance of plasticity presented here is timely and important.A panel of 12 accessions were used that represent natural variation for this plasticity. The majority of accessions showed temperature-mediated flower size plasticity (scored as fold change between 23’C and 17’C), while 3 accessions lacked plasticity. The authors created a full diallel cross with the 12 accessions and analysed mode of inheritance and combining ability. These are standard methods in quantitative genetics and plant breeding. Although this is not my area of expertise, I believe that the contributing authors have the appropriate expertise to design and analyse these experiments correctly.The authors could estimate the heritability of temperature-mediated flower size plasticity and demonstrate that it has mostly additive, but some non-additive inheritance. They conclude that low heritability and non-additivity make breeding for plasticity challenging. These are important findings that increase our understanding of the genetic basis of phenotypic plasticity. I was left with the impression that the authors were discussing breeding in Arabidopsis at some point (!), so they could check that they make a clear distinction between how their findings can be generally useful for crop breeding (where uniformity is desired), versus how their findings are useful to understand the specific trait under study in Arabidopsis. Comments to Author: In this article the authors analyzed the heritability of temperature-mediated flower size plasticity in Arabidopsis. They showed that among 134 crosses using different parental lines, most showed additive inheritance in flower size plasticity, and only 11 crosses showed dominance inheritance. The findings are interesting and provide evidence of flower size plasticity for breeding.1. Mammo-2 and Or-0 did not exhibit any plasticity, while some accessions showed large plasticity. Is there any possible link between temperature-mediated flower size plasticity and the growth environment of the original place of the accessions?2. The results showed that in most cases the inheritance patterns of the temperature-mediated flower size plasticity were additive. Is this similar with the inheritance patterns of plasticity of traits, for instance flowering time or yield？This can be included in the discussion.3. In fig 2 and fig 3, the labels are too small to read clearly. No accompanying comment. No accompanying comment.


The economic burden of influenza is a significant issue within healthcare system, related to higher medical costs particularly among the elderly. Yet, influenza vaccination rates in the elderly in Malaysia were considerably low as it is not part of Malaysia’s national immunization program, with substantial mortality and morbidity consequences. Therefore, we conducted a cost-effectiveness analysis of quadrivalent influenza vaccine (QIV) for the elderly in Malaysia compared with the current no-vaccination policy. A static cost-utility model, with a lifetime horizon based on age, was used for the analysis to assess the cost-effectiveness and health outcomes associated with QIV. Univariate and probabilistic sensitivity analyses were performed to test the effects of variations in the parameters. The use of QIV in Malaysia’s elderly population would prevent 66,326 potential influenza cases and 888 potential deaths among the elderly, leading to 10,048 potential quality-adjusted life years (QALYs) gained. The QIV would also save over USD 4.4 million currently spent on influenza-related hospitalizations and reduce productivity losses by approximately USD 21.6 million. The ICER per QALY gained from a third-party payer’s perspective would be USD 2216, which is lower than the country’s gross domestic product per capita. A QIV-based vaccination program in the elderly was found to be highly cost-effective, therefore would reduce the financial burden of managing influenza and reduce pre-mature death related to this disease. Early screening of influenza may help lessen the symptoms and disease severity. Currently, a comprehensive action plan was developed that would allow an effective influenza management2. Global estimates associate influenza with 3–5 million severe cases and 290,000–650,000 respiratory deaths annually3. Tropical regions such as Malaysia have no clear seasonal patterns and influenza circulation is year-round, typically with several peaks during the monsoon seasons4. Very few studies were conducted on the burden of influenza disease in Malaysia. From 2005 to 2009, 14.0% of 7117 respiratory specimens from patients with influenza-like illness were positive for influenza virus5. Following this, current surveillance has reported that the influenza-positive rate ranged from 3.6 to 7.3% from the number of samples tested annually, ranging from 5391 to 94056. A previous study has suggested the occurrence of influenza in Malaysia is underestimated due to the method of influenza detection4. Furthermore, influenza is not classified as a notifiable disease, resulting in an underrepresentation of actual cases, as a significant proportion of cases are not confirmed by laboratory testing.Influenza is a highly infectious and acute febrile illness that primarily affects the respiratory tract. It is characterized by a sudden onset of fever (38–40 °C), cough , headaches, myalgia, sore throat and inflammation of the respiratory tract. Severe influenza could cause complications such as pneumonia, septicemia, meningitis and cardiac complications7. Influenza vaccination is strongly recommended for those at higher risk for influenza complications such as the elderly. Prior studies have demonstrated that influenza vaccination could mitigate the risk of influenza-associated complications, reduce mortality rates among children, and protect pregnant women and people with chronic health conditions10. Influenza vaccination also plays a crucial role in reducing the severity of illness in infected patients10. The most widely available influenza vaccines are the quadrivalent influenza vaccines (QIVs), which contain two influenza A strains (H1N1 and H3N2 subtypes) and two influenza B strains (Victoria and Yamagata lineages), as per World Health Organization (WHO) recommendations. Currently, there are a few licensed vaccines available and approved to be used in elderly, which are trivalent (TIV) or quadrivalent (QIV), cell-cultured or egg-based, standard-dose or high-dose, and adjuvanted or nonadjuvanted vaccine. Based on the review of available studies, the high-dose quadrivalent influenza vaccine (QIV) is highly recommended for older people in the 2022–2023 season because it is more effective compared to other types of vaccines11. Besides, a consensus has been made by the Malaysian Influenza Working Group (MIWG) for the elderly to receive influenza vaccine annually12. However, in the event that no high-dose vaccine options are accessible, it is advisable to provide any age-appropriate influenza vaccine12.Vaccination is the best strategy to prevent and control influenza and its complications13. However, a report from one tertiary care centre in Malaysia detected poor uptake of influenza vaccination among older patients14. Meanwhile, a nationwide study reported only 5.5% influenza vaccination coverage rates for the elderly15. One possible reason for the trend was that influenza vaccines are only funded for healthcare workers although healthcare services are meant to be free for the elderly in public facilities. Due to their lower immunity, the elderly are more prone to contracting influenza compared with other age groups16, and are particularly vulnerable to related complications. An Italian study reported that most influenza-related deaths occurred in the elderly17. Therefore, there is a need to include the elderly in a national-level influenza vaccination program to enhance vaccine uptake within this group.The target of influenza vaccine coverage has been agreed to by countries in a World Health Assembly resolution on 28 May 200320. For instance, a Korean study reported that the inclusion of influenza vaccines in the National Immunization Program (NIP) for those aged 50–64 years was cost effective, with QIVs emerging as the preferred option based on its greater protection against influenza B21. To the best of our knowledge, no cost-effectiveness analysis of the influenza vaccine has been performed in Malaysia. To address this gap, we used a cost-utility model to predict the public health impact and cost-effectiveness of QIVs compared with the current no-vaccination policy for individuals aged 60 years and older in Malaysia.The vaccination initiative requires a thorough consideration of potential vaccine costs and savings on treatment and outbreak control related expenses. Cost-effectiveness analyses (CEAs) are widely used to help decision makers choose the most appropriate interventions based on costs and effectiveness within a constrained budget. Across the Asia–Pacific region, several cost-effectiveness studies have been conducted in the use of influenza vaccine in the elderly22. All cases of influenza that were included in this study were identified according to a principal or secondary diagnosis coded in ICD-10 as J09, J10.0, J10.1, J10.8, J11.0, J11.1, J11.8, J12.8 and J12.9, representing influenza and its complications. The vaccine cost applied in this analysis was a public market price published by Sanofi Pasteur. Data from a previous local study was referenced for the administrative costs of a vaccine program23 and medication costs at a general practice  visits and OTC medication for the treatment of influenza, respectively. Cost of GP visits was assumed to be the same as a local study done previously24, considering the majority of influenza-like-illness patients would visit public primary care facilities and the group of experts in the study agreed on two visits per episode of care2.Influenza-related costs were estimated from a societal perspective, i.e. costs to the health care system, costs of over-the-counter (OTC) medication for Malaysians aged 60 years and above, and costs related to productivity losses in the working elderly and their caregivers. Influenza-related hospitalization costs were based on the Casemix database in a Malaysian teaching hospital from 2010 to 2020. Casemix is a patient classification system that groups patient treatment episodes into categories that has similar resource use and same clinical features. Casemix is also known as Diagnosis Related Groups (DRG). The Casemix system used in this study, the MY-DRG, incorporated data from clinical coding based on the International Classification of Disease 10th Revision (ICD-10) for diagnosis and International Classification of Disease, Clinical Modification 9th Revision (ICD-9-CM) for procedures2 and estimates from the Casemix database. The cost was calculated using the human capital approach as previously described25. The estimated average daily productivity (USD 39.72) was calculated based on Malaysia’s gross domestic product (GDP) per capita in 202026, based on the assumption of 40 working hours per week or 8 working hours per day. Employment rates among the elderly were referenced from a recent study done in Malaysia27 while rates among their caregivers were based on the Department of Statistics Malaysia reports28. We estimated the costs of lost productivity of their caregivers due to hospitalization and disability in this population. This is because the caregivers would need to take leave from their work to accompany their hospitalized parents. The productivity lost for the patients and caregivers reflected the societal cost in this study.Indirect costs, which were productivity loss associated with the number of workdays lost and the average length of a hospital stay, were calculated based on expert opinion29. Quality-adjusted life years (QALYs) lost due to influenza were based on surveillance done in the UK for influenza-like illness among people aged over 65 years30. The QALY loss was assumed to be the same for both age groups in the model.The population utility rate was based on the estimated EQ-VAS score of the general adult Malaysian population using EQ-5D31. The influenza vaccination coverage rate was assumed at 75%, reflecting the 2003 World Health Assembly’s goal for the elderly13.The number of non-consulting influenza cases for one consultation was derived from the estimated number of patients with influenza-like illness who sought medical care in Thailand32. Influenza-related hospitalizations rates were estimated based on the probability of hospitalization over flu infection rates33 for people over 65 years old in the US and applied to the mortality rates in Malaysia32. The same formula was used to calculate the GP consultation rates, whereby the probability of outpatient visits for influenza33 in non-high risk populations was applied to mortality rates from a previous published study32.Mortality rates per 100,000 were based on published estimates from a recent study of influenza-associated mortality in Malaysians aged 60–74 years and 75 years and above34.The proportion of illness due to influenza A, A (H1N1), A(H3N2), B, B/Yamagata, and B/Victoria for each year between 2013 until 2019 was gathered from the FluNet database for Malaysia16 and an Italian study35. In this study, the IVE of QIV against influenza A and matched B-lineage influenza were derived from Clement et al.36 and adjusted according to the age groups included in the model. The same source was referenced to estimate IVE against mismatched-influenza B by using the cross-protection rates from the study36. The assumption was that IVE against influenza A(H1N1) and A(H3N2) would be identical. IVE against health outcomes like influenza-related GP visits, hospitalizations, and death in each age group were calculated as described for the Canadian16 and Italian35 model.The average vaccine effectiveness of QIV against influenza A and influenza B, respectively were based on the method adopted in a Canadian model16 and Italy35, to estimate the cost-effectiveness of QIVs. The previous published model has described the impact of switching TIV to QIV with three basic simulations including no vaccination, TIV and QIV and estimated the outcomes of each strategy among all aged groups. Their parameters input was selected based on their country’s preference and data availability. Both of these studies evaluate the cost-effectiveness from the societal and provider perspective35. In contrast, our model described the cost-effectiveness and health outcome of QIV and no vaccination strategy in the elderly mainly from the third-party payer perspective. Health outcomes prevented with QIVs were estimated by subtracting the expected rates of influenza-related health outcomes with QIVs from observed rates in non-vaccinated populations. The outputs included were health-related benefits and the number of QALYs gained, life-years gained and saved workdays. Influenza cases prevented were estimated by adding non-consulting cases to GP visits. The elderly population in the model were stratified into two groups: those aged 60 to 74 years and 75 years and above. The costs of each outcome were derived by multiplying the outcome by the estimated unit cost. Finally, differences in total costs and total QALYs were computed to calculate the ICERs.Our modelling strategy was to estimate the incremental cost-effectiveness ratio (ICER) among the Malaysian elderly population who were vaccinated with QIVs versus those who were not. We developed a static cost-utility model to determine the health and economic impact, as previously designed in Canada37. Life expectancy for Malaysians above 60 years were obtained from national statistics38 and World Data Atlas39. The range of input values and relevant sources included for each parameter in the model are summarized in Table Local data were referenced when available. European or American data mostly were utilized in circumstances where there was insufficient local data or when international evidence was determined to be of higher quality and more valid than evidence derived from the Malaysian setting. The model included all targeted populations that were at risk of influenza-related illness, as identified in a published report40. The cost-effectiveness threshold of willingness to pay were set at USD 30,984, which was equivalent to three times the GDP per capita in Malaysia as recommended by the World Health Organization26.In the cost-utility analysis, the targeted study cohort used for CEA was stratified into two age groups within the vaccinated and unvaccinated study populations. Base case analysis was conducted based on third-party payer and societal perspectives. From a third-party payer perspective, the model only included estimated health costs directly associated with treating, managing, and caring for patients with influenza, which included consultations, hospitalizations, and prescriptions. Indirect costs, specifically productivity loss due to influenza and OTC medications, were included for a societal perspective. The costs and health outcomes were discounted by an annual rate of 3%Deterministic sensitivity analyses (DSA) were conducted to test the effect of single variables on the overall economic conclusions of the model. The tornado diagram was used to visually demonstrate the resulting ICERs when one variable was changed to either the maximum or minimum value within its range. The diagram was used to identify the relative importance of a variable since it could demonstrate if changes to a variable could alter the economic conclusion. A variation of ± 20% was assumed for all parameters except for the discount rate, for which the value was varied from 0 to 5% Table . In an ISubsequently, a multivariate analysis was performed with a probabilistic sensitivity analysis (PSA). Instead of changing one parameter value at a time, the PSA changed all variables at once according to their plausible values by random sampling from their distributions. The model was simulated 1000 times with the PSA from the probability distribution of each parameter. All costs and influenza-related outcome rates such as influenza-related GP consultation rate, influenza-related hospitalization rate and influenza-related mortality rate were assigned to a log-normal distribution. Utility data, vaccine coverage rate, percentage of patients consulting a physician, strain circulation and vaccine efficiency followed a beta distribution . The minimum and maximum ICERs obtained through the PSA were USD 817 and USD 8138, respectively. This finding confirmed that QIV was a cost-effective option in the Malaysian elderly compared with no-vaccination Fig. .11, the standard dose was administered in this study due to its availability in Malaysia. The cost-utility model showed that the QIV was highly cost-effective from the third-party payer’s perspective as the ICER estimates was USD 2216, below the threshold of three times national GDP per capita value . The population aged 60 to 74 years demonstrated the greatest improvements in health outcomes when compared to much older group. The observed result can be attributed to the higher population size within this age category in comparison to individuals aged 75 years and older. Furthermore, the vaccine efficacy is reduced in this population as a result of the changes in their immune system, known as immunosenescence, which can weaken immune responses. This phenomenon may result in a compromised capacity for generating a robust immune response to vaccinations, thereby diminishing their efficacy.In this study, we conducted a full health economy evaluation analysis with the aim of applying the economic modelling method to evaluate the cost-effectiveness of QIV compared with no-vaccination among Malaysians aged over 60 years. Although high-dose QIV is strongly advised for the elderly9. Higher costs observed in this age group were attributed to infection-related complications and an extended hospitalization period.The cost saved was found to be higher among the population aged 60 to 74 years, of which productivity lost due to illness and death dominated the cost saved (USD 14.6 million) followed by hospitalization cost (USD 2.5 million). The cost saved was calculated based on the health outcome avoided by multiplying each case by their respective cost. In this study, hospitalization cost was collected from the casemix database from a teaching hospital in Malaysia. Inpatient cost was estimated at USD1397 per admission among the elderly patients infected with influenza-related disease. The findings of our study revealed a little discrepancy when compared to a prior study, which documented an average cost of USD 8330 for individuals between the ages of 65 and 84 who were admitted to the hospital42. Nevertheless, when QIVs was compared with the TIV, the cost of QIVs was deemed higher than trivalent vaccines. For instance, a study conducted in Taiwan reported an additional cost of USD 394,000 when switching from trivalent vaccines to QIV43. However, this Taiwanese study reported an additional 10,557 QALYs with the utilization of QIVs that yielded an ICER of USD 3015.07. This finding was consistent with the finding of our analysis, which demonstrated that the usage of QIVs would lead to 10,048 QALYs gained and would yield an ICER of USD 2216. Furthermore, the ICER reported by our study was lower than the threshold, which established that QIV was cost-effective. Hence, the adoption of QIVs would be cost-effective and reduce the risk of pre-mature deaths related to influenza, despite showing increments in vaccination costs46.Overall, the adoption of QIV would incur more cost. From the base-case estimates, the use of QIVs would cost USD 22,263,781 more than no vaccination. There were limitations to comparing this finding with existing studies, given that most existing studies compared QIVs with trivalent vaccines (TIV)Based on the guideline on economic evaluation of immunization programs provided by the World Health Organization (WHO), the utilization of static models was deemed suitable for assessing the effectiveness of influenza vaccination within populations that do not significantly contribute to disease transmission. Compared to dynamic models, static models do not account for a herd immunity effect, which can occur particularly in younger populations. However, this should have little effect on our results, as the primary focus of this study was on elderly people. Besides, the vaccine coverage was significantly low among the older people in Malaysia, the indirect impact of herd immunity would be limited.2. According to a current study conducted in Malaysia, 16% of the elderly aged over 65 years are currently employed27. Therefore, the estimation of absenteeism due to workdays lost as well as productivity loss due to pre-mature death for the elderly population was included to reflect the societal perspective. However, the estimation for daily productivity was based on GDP per capita owing to the fact that information on the elderly’s salary was not available. From the third-party payer perspective, loss of productivity due to influenza and premature death was not included in the total costs or in the ICER calculations. Nevertheless, incorporating productivity loss costs in the present study would provide a detailed estimation of the indirect costs of QIV vaccination and influenza disease events. This allows policymakers to make informed decisions that not only improve public health outcomes but also contribute to economic well-being and societal development.In this study, we calculated the patient’s and caregiver’s productivity losses based on the duration of hospitalization and outpatient visits from the Casemix database and expert input33. However, these rates were calculated and adjusted based on mortality rates estimated for Malaysia from a previous study32. Thereby, the estimates reflected to the Malaysia socio-economic and appropriate to apply for the Malaysian elderly population. While this may have affected outcome estimates, the sensitivity analysis shows that the effect was minimal in the base case. Second, we adjusted the vaccine efficacy data from previous literature to fit the age groups used in the model. Notably, the vaccine efficacy did have an impact in the study model, as shown in the sensitivity analysis. However, most important finding of the study was that QIVs were effective for preventing death and improve quality of life in the elderly. It was presumed that the influenza vaccination efficacy (IVE) was equivalent for influenza A(H1N1) and A(H3N2); a similar assumption was made by a previous study35. In our case, this assumption should not have impacted the evaluation of QIV when compared to no vaccination. Finally, due to limited data availability, the value for QALY lost due to influenza was assumed to be the same as a study done in the UK30. This was the most reliable data conducted on the elderly patient and appropriate to apply to the Malaysian population since there was no such data available in Asia and neighboring countries. The value was also comparable with another study conducted in Spain whereby QALY lost in the elderly aged 65 years and above was at 0.006147. The application of disutility value from UK and other high-income countries was also utilized by the Korean and Thailand studies48. Nevertheless, the multiple-one-way sensitivity analysis also demonstrated this parameter had limited impact on the ICER result. The utility score from EQ 5D has not yet been established for Malaysian population. For this reason, the EQ VAS was used as an alternative to the EQ-5D for measuring health-related utility norms for elderly population in this study. The EQ VAS is a vertical visual analog scale where respondents rate their current health state on a scale from 0 to 100, with 0 representing the worst health imaginable and 100 representing the best health imaginable. This provides a direct measure of the respondent’s overall perception of their health status.The developed model had several potential limitations. First, due to insufficient national data, estimates of influenza hospitalization rates and GP consultation rates were based on published literature from other countries49. This study complied to the guideline to ensure that cost-effectiveness analysis is conducted systematically, transparently, and consistently, enabling policymakers, healthcare professionals, and researchers to make informed decisions about resource allocation on influenza immunization program in the elderly population in Malaysia. Our study conclusively demonstrates that the implementation of an influenza vaccination program in the elderly population is notably cost-effective, aligning with guidelines that deem interventions costing less than one GDP as having a higher probability of being considered for funding49. Based on the findings, we put forth recommendations for the Ministry of Health (MOH) to incorporate an influenza immunization program for the elderly into the Malaysia’s National Immunization Program.This study is likely to be the first study in Malaysia that has conducted a comprehensive analysis of influenza vaccination strategy in the elderly in terms of cost and health outcomes. The existing guideline for economic evaluation study was established by the Ministry of Health Malaysia, provide a structured framework for conducting economic assessments of healthcare interventions and technologiesInfluenza-related complications are more common in people over the age of 65. Moreover, they were demonstrated to be particularly vulnerable during the COVID-19 pandemic, thus underscoring the need to increase immunogenicity and avoid premature death in this high-risk group with effective influenza vaccines. This economic model suggested that although QIV would incur higher costs, it led to the highest QALYs gained. Our study provides compelling evidence of the benefits of influenza vaccination program, including its potential to reduce disease burden, improve public health, and save healthcare costs. It is apparent that influenza vaccination is the dominant strategy when considering all health outcome consequences in this assessment. Hence, compared to no-vaccination, QIV would reduce the burden of managing influenzas especially among the elderly.


Transcranial direct current stimulation (tDCS) applied to the primary motor cortex (M1) improves motor learning in relatively simple motor tasks performed with the hand and arm. However, it is unknown if tDCS can improve motor learning in complex motor tasks involving whole-body coordination with significant endpoint accuracy requirements. The primary purpose was to determine the influence of tDCS on motor learning over multiple days in a complex over-hand throwing task. This study utilized a double-blind, randomized, SHAM-controlled, between-subjects experimental design. Forty-six young adults were allocated to either a tDCS group or a SHAM group and completed three experimental sessions on three consecutive days at the same time of day. Each experimental session was identical and consisted of overhand throwing trials to a target in a pre-test block, five practice blocks performed simultaneously with 20 min of tDCS, and a post-test block. Overhand throwing performance was quantified as the endpoint error. Transcranial magnetic stimulation was used to obtain motor-evoked potentials (MEPs) from the first dorsal interosseus muscle to quantify changes in M1 excitability due to tDCS. Endpoint error significantly decreased over the three days of practice in the tDCS group but not in the SHAM group. MEP amplitude significantly increased in the tDCS group, but the MEP increases were not associated with increases in motor learning. These findings indicate that tDCS applied over multiple days can improve motor learning in a complex motor tasks in healthy young adults. Transcranial direct current stimulation (tDCS) applied to the primary motor cortex M1) has been shown in numerous studies to increase primary motor cortex excitability and improve motor skill learning in tasks performed with the hand and arm  has been,3,4,5. MThe vast majority of studies that have applied tDCS to any brain region have involved only one 10 to 20 min practice session . HoweverAlthough the findings of single- and multiple-day tDCS studies have been promising, almost all of them have utilized relatively simple fine motor tasks, such as finger sequences with four digits, two-dimensional arm reaching movements, various pinch grip tasks involving the thumb and index finger, hand/arm dexterity tasks, and single-joint visuomotor tracking tasks ,15,16. IThe primary purpose was to examine the influence of tDCS on motor learning over multiple days in a complex overhand throwing task in young adults. To accomplish this, two groups of participants completed three practice sessions of overhand throws on consecutive days simultaneously with either tDCS or SHAM stimulation. Based on both single-session and multi-day tDCS studies that involved relatively simple motor tasks , it was A total of 46 young adults completed the study . The tDCS group (mean age: 25.7 ± 3.6) and the SHAM group (mean age: 24.2 ± 3.1) both consisted of 13 males and 10 females. Participants were all strongly right-handed based on the Edinburgh Handedness Inventory , with anwww.randomizer.org; accessed on 4 January 2018) by an investigator who was not involved in data collection. The participants came to the laboratory at the same time of day on three consecutive days and completed three identical experimental sessions, with each session lasting ~1.5–2 h. The one exception was that a familiarization involving a short instructional video and an overhand throwing demonstration was completed at the start of the first experimental session. The major experimental steps for a single experimental session are depicted in This study utilized a double-blind, randomized, between-subjects, SHAM-controlled experimental design. Participants were allocated to either a tDCS or a SHAM stimulation group using a Research Randomizer  muscle of the left primary motor cortex to obtain MEPs in the FDI of the right  hand [TMS was performed with a Magstim 200al) hand . ElectroThe TMS component of the protocol proceeded as follows: (1) Identification of FDI hotspot location: TMS pulses were applied while the coil position was optimized so that the FDI motor hot spot could be identified. The corresponding coil position was marked on a scalp cap, and the cap position on the head was denoted with a mark on the forehead. (2) Determination of 1 mV MEP intensity: TMS pulses were usually started at ~55% of maximum stimulator output (% MSO), and the stimulation intensity was adjusted while MEPs were monitored and quantified online until the MEP amplitudes were as close as possible on average to 1 mV. Once this was accomplished, the software program was reset to collect the pre-test TMS block. (3) Pre-test TMS block: twenty-five MEPs were collected using the 1 mV stimulation intensity. (4) Five minutes of tDCS or SHAM stimulation: following the previous step, the TMS cap was removed, the tDCS electrode electrodes were placed on the head, and five minutes of either tDCS or SHAM stimulation was delivered. (5) Post-test TMS block: Immediately after the five minutes of stimulation elapsed in the previous step, three prepared investigators coordinated as quickly and as accurately as possible to remove the tDCS electrodes, reposition the TMS cap and coil, and begin the collection of the post-test TMS block (25 MEPS) as soon as possible using the same 1 mV stimulation intensity. At this time, the participant was instructed to maintain relaxation of the hand and to minimize overall movement. (6) Twenty-minute inter-stimulation period: one investigator set a 20 min time clock (at the end of step four) and enforced a 20 min interval between the end of the five-minute tDCS application and the subsequent start of the 20 min tDCS application period that was performed concurrent with the practice blocks of overhand throwing see .The novel paradigm described above involved a five-minute tDCS application followed by a 20 min interval and was designed to address methodological issues related to MEP quantification before and after tDCS application. It was based on research findings by other research groups in studies that were focused entirely on the influence of different tDCS duration protocols on primary motor cortex excitability and are described briefly below. The paradigm developed for the purposes of this study was piloted in our laboratory for the current study and two other studies . This was undertaken to ensure, as much as possible, that this protocol worked as envisioned.The paradigm was developed based on three interrelated methodological considerations: (1) tDCS given for 3–5 min increases MEPs for a 3 to 5 min period after stimulation ceases ,27,28;  that were encased in sponges soaked with saline solution. The anode was placed over the FDI motor hotspot of the left primary motor cortex, and the cathode was placed over the contralateral supraorbital (M1-SO montage). The anode and cathode were secured in place by rubber straps. As described above, tDCS was delivered for a five-minute period between the TMS pre-test and post-test blocks and for a 20 min period during the practice blocks of overhand throws. Therefore, the two applications of tDCS had the same stimulation parameters other than two different durations. In the overhand throwing trials, the stimulation device was positioned in the backpack , whereasThe overhand throwing task was executed in a manner identical to a previous study in our laboratory that used similar experimental methods , althougx and y coordinates of the 10 stickers directly into a data file on a laptop computer. They also removed the stickers from the target area during the rest interval, and the process repeated for the following block of trials.All participants threw a tennis ball in a manner similar to an overhand baseball throw using the right (dominant) arm. The instructions were to perform every throw as accurately as possible by attempting to hit the target center on each trial. An investigator covered the ball with red chalk before and halfway through each block of 10 trials. This allowed marks to be made that denoted the final endpoint position of the ball after hitting the target area. Thus, participants could use visual feedback of the endpoint of the ball relative to the target center after a trial to facilitate minimizing the distance of the error in subsequent trials. After each trial, that investigator retrieved the ball and gave it back to the participant to start the next trial while another investigator recorded the ball mark in the trial with a very small trial-numbered sticker. Participants stood quietly and rested after each trial block ended while three investigators used the rest interval to measure, record, and enter the endpoint The overhand throwing task was always performed when wearing a tightly fitting small backpack with the tDCS device inside. The tDCS device was only turned on in the practice blocks  and, theA three-dimensional overhand throwing task performed in a manner similar to a baseball throw was chosen as the motor practice task, as it is arguably one of the most complex human movements . Firx, y coordinates and the ball’s final endpoint x, y coordinates  and further analyzed offline using another custom-written script in Signal. MEP size was quantified as the peak-to-peak amplitude for each individual MEP, and the average of the 25 MEPS evoked in each test block was used for analysis. Finally, the control measures of average age, laterality quotient, and 1 mV MEP intensity (three-day grand average) were quantified for each of the two groups.The endpoint error in the overhand throwing task was the primary dependent measure of interest, and the MEP amplitude evoked by TMS was the secondary dependent measure of interest. The dependent variables, age, laterality quotient, and 1 mV MEP intensity, were considered control measures. Endpoint error is the best overall measure of endpoint accuracy and was calculated in accordance with prior studies ,47,48,49tes  × 3 Day  × 2 Test  three-way mixed ANOVA. This analysis used the test block endpoint error only because they were executed without concurrent stimulation. Furthermore, this facilitated comparison of the results to previous three to five-day tDCS studies [Group  × 3 Day . Thus, this second analysis used the average endpoint error value obtained from all seven blocks combined (two tests and five practice blocks) on each day. This complemented the first analysis since our pilot data and a previous single-day study [t-tests were used to compare the online, offline, and total learning effects between the two groups  × 3 Day  × 2 Test . Bivariate linear regression analyses were also utilized to analyze the correlations between MEP amplitude changes between the TMS pre-tests and post-tests and endpoint error changes between the pre-test and post-test blocks involving overhand throwing. These correlations were performed separately for each of the three days and only for the tDCS group. The control measures of age, laterality quotient, and 1 mV MEP intensity were compared between groups with separate unpaired two-tailed t-tests. Post hoc comparisons using Bonferroni adjustment for multiple comparisons were performed to locate where significant differences occurred between pairs of means in all of the ANOVAs described above. The significance level was α < 0.05 for all analyses, and the data are shown as means ± standard errors in the figures.MEP amplitude was analyzed with a three-way mixed ANOVA: 2 Group  × 3 Day  × 2 Test  ANOVA. There was a significant Group × Day interaction , but not day 1 (p = 0.654) or day 2 (p = 0.125). There was also a significant main effect for Test , which indicated that endpoint error was lower in the post-tests compared to the pre-tests. The main effect for Group , main effect for Day , Group × Test interaction , Test × Day interaction , and Group × Day × Test interaction  were all non-statistically significant.The differences in motor learning between the groups were compared across the practice days and test blocks with a 2 Group  × 3 Day  mixed ANOVA. There was a significant Group × Day interaction , but not day 1 (p = 0.441) or day 2 (p = 0.26). The main effect for Day  and the main effect for Group  were both non-statistically significant.The differences in motor learning between groups were also compared across the practice days using average endpoint error data when collapsed across all the practice and test blocks with a 2 Group × Day interactions for total motor learning, a series of separate unpaired two-tailed t-tests were used to compare online, offline, and total learning effects between groups. The analyses revealed that the online and offline effects were non-statistically significant between the tDCS and SHAM groups . However, the total learning effect was significantly  × 3 Day  × 2 Test  ANOVA. There was a significant Group × Test interaction , but not the pre-tests (p = 0.104). Accordingly, there was a significant main effect for Test , which indicated that MEP amplitude was higher in the post-tests compared to the pre-tests. Finally, there was a significant main effect for Group , which indicated that MEP amplitude was higher in the tDCS compared to the SHAM group. The main effect for Day , Group × Day interaction , Test × Day interaction , and Group × Day × Test interaction  were all non-statistically significant.Primary motor cortex excitability differences between groups were compared across practice days and test blocks with a 2 p = 0.476 and p = 0.645, respectively), supported by the r2 values  as indicated in p = 0.007, r2 = 0.727); however, the r value was negative (−0.853).Bivariate linear regressions were performed for each of the three days. Importantly, only participants in the tDCS group who had exhibited both increases in MEP amplitude and endpoint accuracy were included in these analyses. The results revealed that on days 1 and 2, the associations between the changes in MEP amplitudes change in endpoint error (endpoint accuracy) for the tDCS group were all non-statistically significant . The average 1 mV MEP intensity (% MSO) for the whole sample was 51.5%. An unpaired t-test revealed that the 1 mV MEP intensity (% MSO) was not significantly (p = 0.832) different between the two groups .A series of separate unpaired The primary purpose of the current study was to examine the influence of tDCS on motor learning over multiple days in a complex overhand throwing task in young adults, whereas the secondary purpose was to examine the association between tDCS induced increases in cortical excitability and the magnitude of motor learning. This study produced four main findings. First, endpoint error significantly decreased over the three days of practice in the tDCS group but not in the SHAM group. Second, the decreases in endpoint error were due to both online and offline effects in the tDCS group. Third, MEP amplitude was significantly increased in the tDCS group but not in the SHAM group. Fourth, the increases in MEP amplitude in the tDCS group were not positively associated with the degree of improvements in motor learning. Taken together, these findings indicate that M1-tDCS applied over three consecutive days can improve motor learning in a complex motor task in young adults, but these improvements are not associated with tDCS-induced changes in primary motor cortex excitability.Motor learning refers to a relatively long-term improvement in motor performance due to extensive practice. It is usually quantified at a minimum of several hours or one-day following practice. In contrast, motor skill acquisition refers to a relatively short-term change in motor skill measured during a single practice session or within a couple of hours following practice. In addition, the physiological mechanisms and adjustments underlying the motor skill and motor learning processes over these distinct time periods in normal practice circumstances are different in some respects . SimilarThe current study was the first to our knowledge that has investigated the influence of tDCS applied to the primary motor cortex on motor learning over multiple days in a complex motor task involving whole-body coordination. It was hypothesized that the tDCS group would display greater total motor learning over the course of the three days of practice and stimulation compared to the SHAM group . Consistent with this hypothesis, endpoint error slowly and progressively decreased with practice in the tDCS group by approximately 22% by the end of day 3. In contrast, the SHAM group experienced an improvement in endpoint error of only about 2% in this difficult motor task at the end of day 3. These differences in total motor learning, however, were not accompanied by statistically significant between-group differences in online or offline learning C. This wThe results of the present study are congruent with most of the prior single-session tDCS studies by other research groups  that utiOverall, the current outcomes are also generally in accordance with two previous M1-tDCS studies that utilized the SVIPT of the thumb and index fingers but also displayed a few nuanced differences. First, the magnitude of difference between the tDCS and SHAM groups in total motor learning appears to be less (~22%) compared to at least 40% between-group differences that the figures in the studies by Reis and colleagues ,13 appeaTranscranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that, in single or paired-pulse mode, can be used to assess corticospinal excitability at rest and during muscle activity. A TMS pulse applied at a stimulation intensity above the threshold to the primary motor cortex elicits an electromyographic (EMG) response termed the motor-evoked potential (MEP). The MEP is one of the most common measurements in the neurophysiology of movement studies and provides a global measure of net corticospinal excitability. Thus, one of the primary experimental uses of the MEP is to quantify physiological changes in the primary motor cortex before and after some intervention. Accordingly, in the present study, MEPs in response to single-pulse TMS were recorded before and after the application of anodal tDCS to measure changes in primary motor cortex excitability.Anodal tDCS delivered to the primary motor cortex usually increases both motor skill and primary motor cortex excitability as measured by MEP amplitude evoked by single-pulse TMS. These are common observations that have been reported in studies that measured only one of these variables or in studies that have measured both in the same study. Furthermore, the increases in motor skills and MEPS were shown to be positively correlated in some initial studies ,21. Baser2 values were exceedingly small on days 1–2, and the r value was even negative for day 3 [For MEP amplitude, the major overall finding was that tDCS significantly increased MEP amplitude from the pre-tests to the post-tests on all three days  but was or day 3 A–C, whicor day 3 ,21 but aor day 3 . This stor day 3 .The exact physiological mechanisms underlying the lack of association between increases in motor learning and MEP amplitude induced by tDCS are not known precisely and were not investigated in the most extensive prior study on the topic . FurtherThe findings of the current study could have clinical implications in numerous populations if long-term tDCS application could elicit similar or even greater complex motor task improvements in neurological disorders than those observed in healthy young adults; for example, children with autism spectrum disorder ,62 and cDespite the rather straightforward findings that tDCS improved motor learning to a greater degree than SHAM stimulation, this study had some limitations that should be recognized. First, the study lacked long time-scale motor learning retention tests as it only contained post-test blocks performed 5 min after stimulation each day. It would have been ideal to have participants return for follow-up testing in the days, weeks, or even months after stimulation and practice had ended, as conducted previously . Second,Future studies should also investigate the interrelated issues of individualization of tDCS application, different stimulation parameters , population studied, and other types of brain stimulation. In regard to individualization, accumulating evidence suggests that the interindividual susceptibility and the variability of performance responses to tDCS could result from some combination of differences in anatomical and physiological factors . ThiThe main finding was that endpoint error significantly decreased over the three days of practice in the tDCS group but not in the SHAM group. Thus, M1-tDCS was able to improve motor learning in this complex motor task to a greater extent than practice alone in healthy young adults. The greater total motor learning exhibited by the tDCS group was accomplished through both greater online and offline learning effects. tDCS also significantly increased primary motor cortex excitability, but these excitability increases were not significantly positively associated with the amount of motor learning. The results confirm and extend the overall tDCS motor learning literature in simple motor tasks. However, the magnitude of motor learning participants displayed in this complex motor task did not seem to be as high as that previous multi-day M1-tDCS studies involving a pinch grip task ,13.