Following the emergence of SARS-CoV-2, various reports suggest that there has been a significant increase in substance abuse due to social distancing and related issues. Several reports have suggested the impact of chronic substance use on individuals’ physiological and psychological health. Therefore, there is a need to know the impact of SARS-CoV-2 on persons with substance use disorders. Individuals with substance use disorders are the most vulnerable groups and are at a high risk of SARS-CoV-2 infection due to their already existing health issues associated with substance use. This review discusses some of the molecular and systemic/organic effects chronic substance use such as alcohol, nicotine, marijuana (cannabis), opioids, methamphetamine, and cocaine have on SARS-CoV-2 infectivity and its potential cause for worsened disease outcomes in persons with substance use disorder. This will provide healthcare providers, public health policies, and researchers with the needed knowledge to address some of the many challenges faced during the Covid-19 pandemic to facilitate treatment strategies for persons with substance use disorders. SARS-CoV-2 is a highly pathogenic member of the coronavirus family . BelongiSARS-CoV-2 can infect all immune cells  leading to hypercytokinemia (cytokine storm) resulting from immune dysregulation –7. The eThe COVID-19 pandemic has not only impacted the health of people but health care systems and policies around the world , 13. TheA recent report by the Center for Disease Control and Prevention (CDC) suggests that the number of deathsfrom substance overdose in the United State is over 932,000 since 1999 . The mosPeople with substance use disorders are often subjected to chronic illnesses such as COPD, arrhythmias, myocardial infarction, hypertension, diabetes, and cardiac insufficiency –22, whicCurrently, there is little information regarding the direct effect SARS-CoV-2 has on individuals with substance use disorder in terms of the individual’s organs and systems. Therefore, in this review, we discuss the molecular and systemic/organic effects chronic substance use such as alcohol, nicotine, marijuana (cannabis), opioids, methamphetamine, and cocaine have on SARS-CoV-2 infectivity, and how SARS-CoV-2 may worsen disease outcomes in persons with substance use disorder based on the limited published articles The surge of the COVID-19 pandemic resulted in disruption to health care and an increase in alcohol use, resulting in serious health repercussions in people with alcohol use disorders (AUD) , 27. WorExcessive alcohol consumption can cause immune system impairment, liver cirrhosis, and other complications that can be associated with worsened outcomes in respiratory disorders –30. As aAs previously stated, long-term use of alcohol can be extremely detrimental to an individual’s health . AlcoholAlthough these findings suggest a possible worsened outcome in persons with AUD it does not necessarily support a direct worsened disease outcome in these individuals. Research and experimental data must be published to indicate the direct association between SARS-CoV-2 and alcohol use disorder causing worsened disease severity.Nicotine, while one of the leading causes of preventable death in the United States, also saw an increasing trend of use during the pandemic . The addSince the emergence of SARS-CoV-2 in 2019 many diverse factors have been linked to the severity of the disease among tobacco smokers since they both impact the respiratory system –47. Overin silico) where they identified an interaction between nAChRs and a toxin-like sequence in the receptor-binding domain of SARS-CoV-2 spike glycoprotein , [, [in vitanalysis . IL-6 ananalysis . They alanalysis . Similaranalysis . They reanalysis  after a analysis , 101. Inanalysis  were alsanalysis  and ACE2analysis , 103. Tranalysis , 105, suanalysis . The dowanalysis . Cannabipression , 85, 87.Although some cannabis products may have potential therapeutic properties against SARS-CoV-2, there are side effects that need to be regarded such as a risk of drug interactions with other COVID-19 drugs, and the route of drug administration like vaping which can be detrimental to health .During the SARS-CoV-2 pandemic, there has been a surge in marijuana use . While mIn terms of the beneficial and detrimental effects, marijuana and nicotine behave similarly as both are inhaled substances. Nonetheless cannabis use disorder could potentially pose a risk factor in COVID-19 patients since long term use of marijuana has increased the morbidity rate. Evidently, more experimental research needs to be conducted to associate marijuana use with the potential for worsened disease outcomes in these individuals.A global study conducted in 2016 indicates that about 26.8 million people live with opioid use disorders (OUD) of which more than 100,000 die annually including over 47,000 people in the USA . SimilarResearch has shown an increased risk of severe COVID-19 associated with opioid use –119. IndAlthough there have not been specific studies conducted on the molecular effects of opioid abuse on SARS-CoV-2 infection, many published articles have established a correlation between the effect of opioid abuse on individuals’ health and the risk that may be presented when people with opioid use disorders (OUDs) are infected with the virus , 122. A Another study suggests that opioid users are at an increase from COVID-19 due to the suppression of immune functions by opioids . OpioidsOpioids can lead to both respiratory depression and kidney damage. COVID-19 can also cause severe acute respiratory infections in many patients . There iThe published data suggest a negative correlation between OUD and COVID-19, although there is relatively little data to date there is the need for distinct evidence to support the potential cause for worsen disease outcome in persons with OUD as these populations are vulnerable and have a high risk of death.Methamphetamine is a common drug of abuse used by people regardless of age. Methamphetamine use is usually preceded by a previous drug abuse history with opioids, alcohol, cocaine, or heroin. A study conducted from December 2019 to November 2020 during the early stages of the COVID-19 pandemic found that methamphetamine use increased 37 % from the previous year . People Methamphetamines euphoric effects are caused by monoamines released during use that act on the dopaminergic, noradrenergic, and serotonergic pathways in the neurological system. Dopamine then can target central pathways such as the nigrostriatal pathway and the mesocortical and mesolimbic circuit . DistribMethamphetamine can impact the immune system in a few ways. Altering the efficiency of B cells and disrupting communication between the innate and adaptive cells by cytokines may delay response to pathogens such as COVID-19. Methamphetamine can reduce the numbers of circulating immune cells such as dendritic cells, monocytes, natural killer cells and macrophages, predisposing these users to a higher risk of infection for all viruses, including SARS-CoV-2 .Methamphetamine causes damage to the lungs by increasing oxidative stress . In condMethamphetamine causes an increase in inflammatory markers such as LC3 . FurtherNeurodegenerative changes in methamphetamine users are also commonly seen in those with chronic use. Changes such as a loss of dopamine transporters, serotonin transporters, and a loss of dopamine levels have been found in brains of methamphetamine users . Brain sNeurotoxicity induced by methamphetamine is caused by a decrease in DA, DA transporter, serotonin vesicular monoamine transporter type 2 (VMAT2), and tyrosine hydroxylase . Due to Methamphetamine is an amphetamine analog most commonly smoked using various non-sterile methods with some exposing users to dangerous unknown drugs and bacteria. Chronic use has been associated with immunosuppression, causing a lower immune response to fight off infections such as COVID-19 . ChronicThe pathogenesis of methamphetamine induced lung injury is not well understood but chronic use has been linked to lung damage . InhalatCognitive impairments from methamphetamine use results in neurological deficits such as memory loss and changes in decision making and information processing . MethampWith chronic use of methamphetamine, brain damage predisposes these patients to both neurologic and pulmonary COVID complications. Further research is required to see if neurological deficits related to methamphetamine use could put people at risk of developing long term complications of COVID such as the cognitive impairments mentioned above. Due to methamphetamine and COVID targeting similar organs, the brain and lungs, a correlation could be drawn that each will negatively affect the other. Brain and lung damage in methamphetamine users could impact COVID infection and its consequences. Just as in people with chronic lung conditions such as asthma or chronic obstructive pulmonary disease, people who use methamphetamine may have negative impacts on disease progression with COVID-19 due to previous damage from methamphetamine.In 2021, a national survey was used to conduct the usage of cocaine among people 12 years or older in the United States. In the last 12 months, there were around 4.8 million people that reported the use of cocaine . In the Cocaine is an addictive substance, that with excess consumption causes major complications. The exposure side effects of cocaine use are seen in many areas in the body, including the brain, cardiovascular, lungs, and immune system . The abuAs mentioned, COVID-19 and the use of cocaine concomitantly leads to an increase of inflammatory markers, leading to a higher risk of complication for the patient. The next section will bring into account the need to discuss the organs that are affected by the combination of both stimulant and virus.Cocaine can be administered in many different ways, including intranasally, inhalation or intravenously. Patients with a cocaine use disorder can experience many side effects by the usage of cocaine only. When combined with the COVID-19 infection, these side effects can lead to major complications. As mentioned, patients with COVID-19 who have a cocaine use disorder will have a greater chance of having COVID-19 complications, but this does not correlate with decreased life expectancy . A studyCocaine stimulates the sympathetic nervous system leading to the inhibition of catecholamines re-uptake, affecting the cardiovascular system . AdditioCocaine can also affect the respiratory system therefore exacerbating the synergistic effect of COVID-19 in the lungs. After developing cocaine toxicity, some pulmonary complications are seen, with patients experiencing shortness of breath, wheezing, and chest pain . In patiPeople with a cocaine use disorder are considered more susceptible to the infection of SARS-CoV-2 which has brought into concern the neurological symptom as well. Cocaine produces its effects in the brain by stimulating the mesolimbic dopamine system causing similar symptoms in COVID-19. SARS-CoV-2 and cocaine have a synergistic effect on the blood brain barrier (BBB), increasing the permeability to toxins, therefore causing an increased risk in the central nervous system. The disruption of the BBB permeability exacerbates the symptoms encountered in both cocaine use and COVID-19 . The damThe purchase of CBD, a component of the cannabinoid family, has increased in popularity due to availability without a prescription. CBD is being used for many different reasons, including stress, anxiety, sleep and pain. Increased ease of access has led to increased consumption. There is, however, concern for the side effects of CBD due to limited data in their safety and efficacy .The properties of cannabinoids depend on their interaction with the endocannabinoid system including G-proteins coupled receptors and transient receptor potential channels . CBD1 anPre-clinical studies show that some cannabinoids may have an impact on the inflammatory response in mouse models of lung or inflammatory diseases . InhibitOne study assessed antiviral activity of CBD and Δ9-THC against SARS-CoV-2. The study showed blocking of viral translation of SARS-CoV-2 and reducing pro-inflammatory cytokines levels in the lungs by acting as agonists of the CB-2 receptor . Δ9-THC Other studies have assessed if CBD could help with the rise in mental health conditions from the COVID-19 pandemic. Due to the pandemic an unprecedented outcome was established between the pandemic and neurological complications such as anxiety and depression. An estimate of 45 % of adults in the US reported that their mental health was affected due to the COVID-19 pandemic . Due to In a study on the interaction between cannabinoids and SARS-CoV-2 spike protein, an interaction was found that two cannabinoids, cannabidolic acid and cannabigerolic acid, may block infection of human cells by SARS-CoV-2 expressing the spike protein . BlockinThe anti-inflammatory properties of CBD may be beneficial for preventing worsening of disease from inflammation due to COVID-19, but caution is needed regarding the risk of abuse with cannabinoids and guideline recommended alternative therapies with no risk of abuse or addiction unlike cannabinoids.Dependence on drugs of abuse is associated to increased morbidity and mortality , 19, 22.Chronic alcohol consumption leads to increased SARS-CoV-2 infectivity and viral susceptibility. Alcohol consumption increases ACE2 expression, the entry point of the pathogen while altering proinflammatory cytokines , 38. HeaAlthough some studies suggest that tobacco (nicotine) may protect the lungs against SARS-CoV-2 by restoring the NCS and anti-inflammatory pathway, more recent studies suggest otherwise . NicotinSimilarly, studies on marijuana (cannabis) use suggest it may have some therapeutic effect in protecting the lungs by acting as an immunomodulatory agent in suppressing cytokine storm triggered by SARS-CoV-2 –85. AlthThe vulnerability of people with opioid use disorders put them in a comprised health situations when infected with SARS-CoV-2 . AlthougMethamphetamine and cocaine have similar detrimental effects on outcomes in patients with COVID-19. Effects on immune suppression and pulmonary toxicity seen in methamphetamine and cocaine users negatively impact patients with poor health outcomes with infection of SARS-CoV-2. Immune suppression predisposes this population to an increased risk of infections and a lesser ability to fight off the infection while pulmonary alterations can lead to worsening pulmonary complications as seen with COVID-19.Finally, cannabinoids have been shown to have anti-inflammatory properties as well as inhibiting viral attachment to human cells, which helps decrease the likelihood of infections with SARS-CoV-2. While certain cannabinoids show a benefit with inflammation due to viral infections, large concerns include lack of data on safety and efficacy of cannabinoids especially those taken without the Food and Drug Administration approval or oversight.People with substance use disorders have comprised health conditions which makes them more susceptible to pathogen infectivity. Considering this factor, there could be some synergistic effect that poses as a potential cause for worsened disease outcome in these population. However, more research must be conducted to indicate a direct association of the effect SARS-CoV-2 has on persons with substance use disorders.


We examined further variables, such as age, sex and the duration of rheumatoid arthritis. Interestingly, we could not find a correlation between the above variables and abnormal neural structural changes in the cornea. We interpreted these findings via implementing our hypotheses. Correspondingly, one neuroimmunological link between dry eye and rheumatoid arthritis could be through the chronic Piezo2 channelopathy-induced K2P-TASK1 signaling axis. This could accelerate neuroimmune-induced sensitization on the spinal level in this autoimmune disease, with Langerhans-cell activation in the cornea and theorized downregulated Piezo1 channels in these cells. Even more importantly, suggested principal primary-damage-associated corneal keratocyte activation could be accompanied by upregulation of Piezo1. Both activation processes on the periphery would skew the plasticity of the Th17/Treg ratio, resulting in Th17/Treg imbalance in dry eye, secondary to rheumatoid arthritis. Hence, chronic somatosensory-terminal Piezo2 channelopathy-induced impaired Piezo2–Piezo1 crosstalk could result in a mixed picture of disrupted functional regeneration but upregulated morphological regeneration activity of these somatosensory axons in the cornea, providing the demonstrated abnormal neural corneal morphology.The purpose of our study was to analyze abnormal neural regeneration activity in the cornea through means of confocal microscopy in rheumatoid arthritis patients with concomitant dry eye disease. We examined 40 rheumatoid arthritis patients with variable severity and 44 volunteer age- and gender-matched healthy control subjects. We found that all examined parameters were significantly lower ( Rheumatoid arthritis (RA) is one of the most frequent chronic autoimmune diseases, with synovial inflammation and bone erosion features. The etiology of RA is not entirely known, with associated genetic and environmental risk factors, but it involves both the innate and adaptive immune systems in inflammatory processes that also pertain to activation of immune-complex-mediated complements and overproduction of proinflammatory cytokines .Dry eye disease (DED) is a complex multifactorial and heterogeneous condition of the ocular surface, characterized by symptoms of ocular discomfort and irritation. Despite significant progress in our understanding of this debilitating disease, its precise etiology is yet to be elucidated ,3,4. Intv1.3 ion channel was found to be a likely susceptibility gene of ALS [Nobel laureate Ardem Patapoutian and his team identified the Piezo2 ion channel as the principal ion channel responsible for proprioception . It has e of ALS , as it ie of ALS , and thie of ALS  and leade of ALS . Furthere of ALS . Thus, tThere is an unmet need to further explore the potential role of the corneal neuroimmune mechanism in development of DED in autoimmune diseases, such as in RA. In brief, we theorize that chronic Piezo2 channelopathy on corneal somatosensory terminals could lead to lost functional remodeling and regeneration capacity of the cornea, and as a result, the morphology could show an abnormally diminished regenerative picture of nerve fibers in DE secondary to RA. Therefore, our aim was to investigate signs of reduced regeneration activity in corneal sensory afferents using confocal microscopy.The demographics and clinical data of patients are summarized in Confocal corneal microscopy of the subepithelial layer clearly demonstrated a significant decrease in corneal subepithelial nerve plexi. Not only the density but the thickness of the nerves and the number of branches revealed damaged nerve structure .2), corneal nerve-branch density , corneal nerve-fiber length , corneal nerve-fiber total branch density , corneal nerve-fiber area  and comparison of the RA and the control samples resulted in significant differences (p < 0.05). In all of the cases, the RA-sample means were significantly lower than in the control samples  or TBUT or OSDI score. In some cases, significant correlations were observed between the variables for the RA samples . CNFD AvMultivariate correlations were also performed in order to detect complex relations among systemic descriptives and dry-eye parameters as well as corneal nerve structural changes, but no significant correlation could be detected.Several subgroups were created in the RA group, with the aim to identify influencing factors of corneal nerve changes in RA. No difference was found between male and female patients. Age did not have any effect on the changes; the subgroups of patients under and over 50 years had no difference. Disease duration did not affect corneal nerve structures either; no difference was found between patients with less than and more than 10 years after disease onset. The corneal nerve parameters in the subgroups determined by the DAS28 score to be under and over 2.6 had no significant difference.Our study found that corneal nerve structure was significantly altered in our RA-related DE subjects. We found evidence of disrupted regeneration activity due to neural damage in the form of decreases in the number, density and length of the sub-basal nerves, along with decreased density of corneal branching points. The current authors suggest that this disruption in regeneration of nerve fibers could have been the result of impaired crosstalk between corneal somatosensory-terminal Piezo2 and peripheral-cell Piezo1 due to chronic Piezo2 channelopathy.2P channels [2P channels have a well-known role in autoimmune attacks in the central nervous system and in neurodegeneration through the TWIK-related acid-sensitive K+ channel 1 (TASK1) pathway [2P channel activation through TASK1 channels on the spinal level could promote one pathomechanistic link between autoimmune diseases and DE. An indicative finding of this theory is that K2p5.1 channel expression in CD4+ T lymphocytes in the peripheral blood correlates with disease activity in RA [Noteworthily, Piezo ion channels facilitate the mechanogating feature of Kchannels , and K2P pathway . Moreove pathway  with a s pathway ,21. The ty in RA .+/CD56+ natural killer-T cell (NKT cell) levels are elevated in the initial stage of the disease process as a first-line cellular innate response but NKT cells are depleted in later stages [+IL-17+ (Th17) T helper cell frequencies and shift Th17/T regulatory (Treg) balance, while CD4+IFN-γ+ (Th1) T helper cells decrease as the/ratio between Th1 and CD4+IL-4+ (Th2) decreases in an autologous way through IL-6 modulation in RA [We presented earlier that corneal Langerhans cells (LCs), a type of dendritic cell, are activated in RA and may play a central regulator role in local corneal immune responses through activation of the innate immune system . Noteworr stages . Indeed,r stages . It is pr stages . It has r stages  and indur stages ,27,28,29on in RA . Hence, on in RA , could lTocilizumab, an IL-6 antagonist monoclonal antibody, reduces IL-33 levels in RA . The rolIt is important to note that Fernandez-Trillo et al. highlighted the special genetic-signature feature of corneal Piezo2-containing somatosensory fibers in the cornea . FurtherNotably, painless primary noncontact somatosensory Piezo2 terminal microdamage is suspected to impair intimate crosstalk between the somatosensory Piezo2- and Piezo1-channel-containing peripheral cells in the cornea . Since t2P channel, through the TASK1 channels, could accelerate this neuroimmune-induced sensitization on the spinal level in autoimmune diseases with concomitant exaggerated LC activation that could also lead to a morphological picture of upregulated regeneration activity of Piezo2-containing somatosensory axons in the cornea. This upregulated regeneration is functionally incomplete as well.Indeed, repeated noncontact reinjury of Piezo2-containing somatosensory terminals could lead to chronic Piezo2 channelopathy or sensitization, especially in the presence of underlying genetic and environmental risk factors . CorrespThe aforementioned halted and incomplete functional regeneration is associated with a depletory picture in DE and RA not only in terms of the innate and adaptive immune system but in other terms as well. Correspondingly, a recent study demonstrated that a replenishing synthetic tear protein was capable of promoting corneal nerve regeneration even in the presence of associated chronic inflammation via restoring the depleted functional nerve supply . That st2P-TASK1 signaling-axis activation that could further amplify this process in autoimmune diseases.This is not to mention that the study of Efraim et al.  most likEfraim et al. emphasized in their paper the essential structural and functional roles of nerves in tissue homeostasis and progenitor cell maintenance , as we eIn DE, another answer could be that repetitive ECM damage due to shear stress from tear-film motion and blinking, as well as resultant ECM reorganization, depletes proteoglycans. Indeed, instillation of a chondrocyte-derived ECM facilitated improvement in a mouse model of DE . Hence, Our findings are also interesting in reference to the suggested primary damage of Piezo2-containing somatosensory nerves contributing to proprioception, highlighting that both RA and DED are more prevalent among women . HoweverIt is important to emphasize that applying the aforementioned published Piezo microinjury hypotheses and using a multidisciplinary approach in this interpretation of the potential neuroinflammatory pathomechanism in regards to the current abnormal corneal neural structural findings were not meant to challenge any earlier scientific research; on the contrary, they were meant to incorporate it.One obvious limitation of our investigation is that it was an earlier cross-sectional study, and the reanalysis from a neurocentric view was not part of the original research design. Thus, the results could be considered as preliminary verification of a theory, and further investigation is recommended, with specifically tailored research design and more emphasis on tracing the molecular background of this revealed abnormal neural corneal morphology.This study was a cross-sectional, comparative study of 40 patients treated, with variable severity of RA, and 44 age- and gender-matched healthy volunteers as control subjects. This study was approved by the Central Ethics Committee of Hungary . Each participant gave written informed consent about the examinations. All examinations were carried out in accordance with the tenets of the most recent revision of the Declaration of Helsinki.The RA patients were classified according to the American College of Rheumatology/European League Against Rheumatism  criteria . The DASFirst, dry-eye-related signs and symptoms were evaluated. Assessment of subjective ocular discomfort related to DE symptoms was performed using the OSDI questionnaire to evaluate subjective ocular discomfort . The stu®, Heidelberg Engineering GmbH) to keep a stable distance between the cornea and the microscope head. One drop of artificial tear gel  was used as a coupling medium to ensure airless contact. Two-dimensional en face images were taken of the SBNP in the central cornea using a 400 µm field-of-view lens. All examinations were carried out in the same room under unchanged conditions.Then, in vivo corneal laser-scanning confocal microscopy was performed to describe the morphology of the SBNP. All patients were examined with the Rostock Cornea Module of Heidelberg Retina Tomograph-III  equipped with the built-in software Heidelberg Eye Explorer version 1.5.10.0. Before the examination, one drop of oxybuprocaine hydrochloride  was instilled topically. The microscope lens was covered by a sterile-packaged disposable polymethyl methacrylate cap (TomoCap2).ACCMetrics V.2 software was used to evaluate the morphometric parameters of the SBNP . A set op < 0.05.Variables of the selected sample were presented as means and standard deviations. For the purpose of selecting the adequate statistical procedure, the Shapiro–Wilk W test of normality was calculated. For comparison of the measured datasets, an independent sample t-test and a Mann–Whitney U test were performed. To further support the results of this study, we calculated and included effect-size (ES-Cohen’s d) values. For the correlation analysis, Pearson’s parametric and Spearman’s nonparametric calculations were performed. Statistical calculations were executed with Statistica software  and JASP software . The significance level was determined in all cases to be 2P-TASK1 signaling-axis activation. In summary, the referenced chronic corneal sensory-terminal Piezo2 channelopathy could result in the observed broken and dysfunctional regeneration activity in association with the theorized activated transcription, impaired Piezo2–Piezo1 crosstalk, activated LCs, activated corneal keratinocytes and breaks in the wound-healing process, not to mention a Th17/Treg imbalance in the neuroinflammatory link.The results of our confocal microscopy study demonstrated that indeed, corneal sensory afferents show reduced regeneration activity with underlying damaged nerve structure in DE secondary to RA. All investigated parameters were significantly lower in the RA patients compared to the control samples, such as the number of fibers, the total length of the nerves, the number of branch points on the main fibers, and the total nerve-fiber area. The authors of this manuscript propose that the observed corneal sensory morphology could have been the result of impaired crosstalk between corneal somatosensory-terminal Piezo2 and peripheral-cell Piezo1 due to chronic Piezo2 channelopathy. Moreover, the authors theorized that this corneal somatosensory-terminal Piezo2 channelopathy could evolve due to even noncontact mechanoenergetic corneal sensory-afferent damage crosslinked with underlying RA-derived spinal K


Subjects with bicuspid aortic valves (BAV) are at risk of developing valve dysfunction and need regular clinical imaging surveillance. Management of BAV involves manual and time-consuming segmentation of the aorta for assessing left ventricular function, jet velocity, gradient, shear stress, and valve area with aortic valve stenosis. This paper aims to employ machine learning-based (ML) segmentation as a potential for improved BAV assessment and reducing manual bias. The focus is on quantifying the relationship between valve morphology and vortical structures, and analyzing how valve morphology influences the aorta’s susceptibility to shear stress that may lead to valve incompetence. The ML-based segmentation that is employed is trained on whole-body Computed Tomography (CT). Magnetic Resonance Imaging (MRI) is acquired from six subjects, three with tricuspid aortic valves (TAV) and three functionally BAV, with right–left leaflet fusion. These are used for segmentation of the cardiovascular system and delineation of four-dimensional phase-contrast magnetic resonance imaging (4D-PCMRI) for quantification of vortical structures and wall shear stress. The ML-based segmentation model exhibits a high Dice score (0.86) for the heart organ, indicating a robust segmentation. However, the Dice score for the thoracic aorta is comparatively poor (0.72). It is found that wall shear stress is predominantly symmetric in TAVs. BAVs exhibit highly asymmetric wall shear stress, with the region opposite the fused coronary leaflets experiencing elevated tangential wall shear stress. This is due to the higher tangential velocity explained by helical flow, proximally of the sinutubal junction of the ascending aorta. ML-based segmentation not only reduces the runtime of assessing the hemodynamic effectiveness, but also identifies the significance of the tangential wall shear stress in addition to the axial wall shear stress that may lead to the progression of valve incompetence in BAVs, which could guide potential adjustments in surgical interventions. The aorta is the main artery in the human body, with the life-sustaining role of distributing oxygenated blood to all parts of the body via systemic circulation. With its complex morphology, it has been extensively researched to explore the space of parameters that can impact the biomechanical function of the aorta . The bicMeierhofer et al.  utilizedThe analysis of 4D-PCMRI faces challenges due to its relatively long lead times, requiring manual segmentation and the process of identification of anatomical landmarks for localizing flow characteristics. To address these limitations, machine learning (ML) algorithms have been employed to fully automate the cardiac imaging workflow ,19. PrevThe study aims to test ML-based segmentation using MRI data to analyze vortical structures and wall shear stress in subjects with BAV and contrast it against normal TAV. With the use of ML-based segmentation, this study aims to provide a physics-based understanding of the biomechanical characteristics of the aorta and provide valuable insights for clinical practice.The present study used cardiac MRI data sets acquired at Cincinnati Children’s Hospital Medical Center (CCHMC). All demographic information was anonymized  and CCHMC Institutional Review Board deemed the study to be exempt from any ethical inquiries ,3,4. TheAll MRI scans were performed using a 1.5 Tesla clinical MRI scanner  using a phased-array coil. The study of the protocol for the long-axis sagittal stack 4D phase-contrast magnetic resonance imaging (4D-PCMRI), the short-axis aortic root cine stack, and the aortic root phase-contrast velocity sequence was carried out, in addition to the noncontrast 3D mDixon angiogram for analysis. The short-axis aortic root cine stack was obtained using a steady-state free precession pulse sequence with specific parameters: a repetition time of 7.8 ms, an echo time of 4.7 ms, a flip angle of 15°, and sequential 2 mm slices without an interslice gap. For the short-axis aortic root phase-contrast velocity encoded sequence, a gradient echo sequence was employed with a repetition time of 4.3 ms, an echo time of 2.7 ms, a flip angle of 12°, and a slice thickness of 6 mm. The encoding velocity for this sequence was set at 1.5 m/s. Each cardiac cycle was represented by 30 phases for both sequences, resulting in a mean temporal resolution of 30–40 ms. The non-contrast coronal 3D mDixon angiogram was acquired using a repetition time of 5.3 ms, a flip angle of 15°, and 1 mm slices with no interslice gap. The 4D-PCMRI sagittal stack was obtained using a velocity encoding of 2 m/s, s repetition time of 3.5 ms, an echo time of 1.9 ms, and a flip angle of 8° [Semantic segmentation is one of the oldest problems in computer vision . It is dIt is possible to approximately classify the many instances of ML implementations for semantic segmentation problems in three main groups: weakly supervised methods , region-A particularly successful U-Net based implementation specialized in biomedical images is the so-called nnU-Net . Its maiThe main advantage of TotalSegmentator is that it can segment a wide range of clinical data  with superior performances concerning other publicly available algorithms ,33,34. CThe ML-based segmentation algorithm identified most of the larger cardiovascular structures: left atrium, left ventricle, myocardium, right atrium, right ventricle, pulmonary artery, and aorta; see The calculation of pulse wave velocity (PWV) involves two crucial parameters: the Aortic Length measurement and the time interval between the upslopes of the flow curves. The time interval is determined by measuring the temporal distance from the point where the tangent of the aortic ascending flow curve reaches zero to the point where the tangent of the descending aorta curve also reaches zero. The calculated PWV values are 3.2 m/s for the TAV case and 3.3 m/s for the BAV case, indicating similar arterial stiffness. The distensibility was assessed using the relation Around the time of peak systole . The velocity gradient is larger on this side compared to the TAV case, resulting in increased axial wall shear stress d. HoweveAV cases .The cross-flow velocity component (y-axis) in the BAV case exhibits more significant levels compared to the TAV case, as illustrated in In the BAV cases, the axial velocity changes signify transitioning from positive to negative flow, which coincides with the location of the vortex core at In this study, we employed machine learning (ML)-based segmentation techniques on an MRI dataset to segment the anatomical structures of the cardiovascular system. The ML-based segmentation approach, trained on CT datasets, exhibited a high level of accuracy, with a Dice score of 0.86 of the main chambers of the heart, which is in good agreement with segmentation using CT data . HoweverThe ML-based segmentation method demonstrated robustness when applied to clinical MRI data, effectively reducing the time required for the entire heart segmentation compared to manual segmentation. The runtime for the segmentation process was less than approximately 2 min, and it demanded about 5 GB of RAM and GPU memory. As a result, this approach can be executed on a workstation, making it practical and feasible for routine usage.The functionally bicuspid aortic valve and trisinuate aortic root discussed in this study are more frequently linked to aortic valve narrowing and aortic enlargement . In thisThese findings have important implications for assessing congenitally malformed valves and providing insights for surgical interventions. Studies have shown that the fusion orientation and the level of hypoplasty of the commissural apex can guide decisions between preserving a functional bicuspid valve or re-configuring it to a tricuspid valve, optimizing the potential for long-lasting repairs ,38.The sub-optimal Dice score obtained for the aorta resulted in segmentation failure of the head and neck vessels, coronary arteries, and the fine details of the valve leaflets. In cases where segmentation failure occurs, it may be necessary to resort to manual segmentation, although this would incur additional turnaround time for the complete segmentation of the heart.One limitation of the ML-based segmentation method employed in this study is that it was trained on ECG-gated CT datasets. Consequently, the study was constrained to utilizing 3D mDixon data that were ECG-gated. Therefore, the physiological displacement of the heart throughout the cardiac cycle could impact the delineation of the 4D-PCMRI data, which evolve both spatially and temporally. This influences the flow quantification in the left ventricle, as it experiences significant volume changes during systolic contraction. However, for vessels that undergo moderate displacement and area changes, this factor is less significant. Nonetheless, including 4D-PCMRI data in the training datasets for the ML-based segmentation would help overcome this limitation and enhance the segmentation performance. This will be the objective of a future study.The study’s scope is constrained by the limited number of subjects, focusing on the functionally bicuspid aortic valve (BAV) with a trisinuate aortic root when compared to the normal trisinuate aortic valve (TAV). Nonetheless, the cohort size in this study is consistent with other studies . SubsequThe examined ML-based segmentation method demonstrated precise measurement of left ventricular volume and accurate identification of the thoracic aorta region, regardless of aortic pathology. These findings suggest that this method holds significant promise as a valuable tool for promptly assessing aortic pathologies like the bicuspid aortic valve in a clinical setting.The quantification of flow structures in TAV and BAV morphologies was accomplished using ML-based segmentation to delineate the 4D-PCMRI flow measurements. Comparative analysis revealed that BAVs exhibited a more pronounced impingement of the jet towards the convex side of the ascending aorta, in contrast to TAVs. At peak systole, the axial vorticity data in the ascending aorta demonstrated that BAV subjects displayed a significant vortex structure with a counterclockwise swirl, which was more prominent than in the normal TAV cases. This is in agreement with previous observations ,16,36. TThe quantitative assessment of vortical flow structures contributes to a deeper understanding of the relationship between hemodynamics in the proximal thoracic aorta and differences in aortic valvar morphology. The Computational Fluid Dynamics model in ideal ,42 and p


A standard treatment for locally advanced rectal cancer consists of trimodality therapy of neoadjuvant radiation +/− chemotherapy, surgery, and adjuvant chemotherapy. There is a need for biomarkers to predict treatment response and outcome with the aim of personalizing patient treatment. We analysed a class of promising biomarkers in the blood, namely circulating tumour cells and the expression of a panel of selected small RNAs (microRNAs) which are known to regulate genes and how cancers behave. We identified these cells in a majority of patients assessed in this study, and also determined microRNA expression changes during the course of treatment. Some of these changes were specifically associated with responses to treatment and could be potentially used to predict how patients respond to treatment. They may also be potential targets for drug development.TM  CTC Isolation and detection platform. We then subjected the isolated CTCs to miRNA expression analyses, using a panel of 106 miRNA candidates. We identified CTCs in 73% of patients at baseline; numbers fell and miRNA expression profiles also changed during treatment. Between baseline and during treatment (week 3) time-points, three microRNAs  were highly differentially expressed. Importantly, hsa-miR-19b-3p and hsa-miR-483-5p were found to correlate with good response to treatment. The latter (hsa-miR-483-5p) was also found to be differentially expressed between good responders and poor responders. These miRNAs represent potential predictive biomarkers, and thus a potential miRNA-based treatment strategy. In this study, we demonstrate that CTCs are present and can be isolated in the non-metastatic early-stage cancer setting, and their associated miRNA profiles can potentially be utilized to predict treatment response.Locally advanced rectal cancer (LARC) has traditionally been treated with trimodality therapy consisting of neoadjuvant radiation +/− chemotherapy, surgery, and adjuvant chemotherapy. There is currently a clinical need for biomarkers to predict treatment response and outcomes, especially during neoadjuvant therapy. Liquid biopsies in the form of circulating tumour cells (CTCs) and circulating nucleic acids in particular microRNAs (miRNA) are novel, the latter also being highly stable and clinically relevant regulators of disease. We studied a prospective cohort of 52 patients with LARC, and obtained samples at baseline, during treatment, and post-treatment. We enumerated CTCs during chemoradiation at these three time-points, using the Isoflux A standard treatment for locally advanced rectal cancer (LARC) is trimodality therapy, consisting of neoadjuvant radiation +/− chemotherapy, surgery, and adjuvant chemotherapy. Despite trimodality therapy, around a third of patients still develop recurrent disease . CurrentLiquid biopsies in the form of circulating tumour cells (CTCs) or circulating nucleic acids (ctDNA and ctRNA) offer the promise of earlier detection of resistance to treatment whilst being relatively non-invasive. Serial liquid biopsies may also allow clinicians to monitor tumour biology and adapt treatments accordingly. There are various methodologies used in isolating CTCs . One of Circulating miRNAs are increasingly becoming a focus of research, as they are highly stable non-coding RNAs thought to regulate up to 30% of the human genome and are potentially key regulators in rectal cancer . The recThe aims of this study were to prospectively assess CTC change and to determine CTC/lymphocyte miRNA expression during the course of neoadjuvant chemoradiation for LARC. Finally, we correlated CTC/lymphocyte miRNA expression levels and change with tumour treatment response. To the best of our knowledge, our study is the first to describe miRNA profiles associated with CTCs isolated immunomagnetically during neoadjuvant chemoradiation in LARC.Patients were prospectively recruited from three centres in the South Western Sydney Local Health District, Australia. The inclusion criteria were: age > 18; tissue confirmation of LARC ; and planned treatment with neoadjuvant chemoradiation. Neoadjuvant chemoradiation consisted of 5-fluorouracil (5-FU) infusion or oral capecitabine concurrent with radiotherapy for 5–6 weeks. This was followed by surgery approximately 6–12 weeks after completion of chemoradiation. Patients were followed up in clinic every 3 months. Recurrence was defined as the appearance of local or distant disease. Ethical approval was obtained from the Sydney South West Area Health Service Ethics Review Committee . CTCs were collected at baseline (pre-treatment), during treatment (at week 3), and post-treatment (within 1 week pre-surgery). Two blood samples were collected using K2EDTA BCTs, the first for enumeration and the second for miRNA analyses. Tumour Regression Grade (TRG) and pTNM staging  were scored by two specialist pathologists on the surgical specimens ,9. All dTM) system, as per the manufacturer’s instructions. For enumeration, immunostaining was performed with anti-CD45 for negative selection of lymphocytes, pan-cytokeratin (CK) for positive selection of epithelial cells and Hoechst for DAPI/nuclear staining. For miRNA analyses, the isolated cell pellet was placed in a cryovial, snap frozen on dry ice, and stored in liquid nitrogen until RNA extraction.A 9 mL blood sample was drawn in a K2EDTA tube and processed within 24 h using the Isoflux® profiling: (i) A review of the literature involving miRNAs previously associated with LARC treatment, with a focus on studies that described change in expression during treatment and association with response; (ii) a review of miRNAs previously shown to be associated with colorectal cancer carcinogenesis and radiosensitivity, and (iii) additional miRNAs identified in a pilot study of rectal cancer patient CTC samples, SW480 cell line, and healthy patient samples using an OpenArray® panel with 758 potential target miRNAs. The candidates from this run were compared against those derived from the literature. Three approaches were combined to select candidate miRNAs for OpenArrayTM  total RNA purification kit as per manufacturer’s instructions. Reverse transcription and preamplification were performed using the TaqMan®  OpenArray® MicroRNA Panels protocol. The diluted preamplified product was subject to polymerase chain reaction (PCR) using QuantStudioTM . Customised OpenArray® miRNA plates containing the selected miRNA targets were used for the study samples. Data were output from the QuantStudioTM platform as CRT values. The QuantStudioTM platform uses CRT, the equivalent of Ct [RNA extraction was performed using the Norgennt of Ct . RT value for each patient, corresponding to 39 patients. The HTqPCR package was used to perform Ct data normalization and differential expression analysis as described below. HTqPCR incorporates the empirical Bayes moderated t-statistics from the limma package, with the associated p-values being used to assess the significance of the observed differential expression [All statistical analyses were performed using the following R packages available from CRAN: BMA (Bayesian Model Averaging) ; or Biocpression .The files were read into R using the HTqPCR function readCtData. Raw data were normalised, and three normalisation methods inside the package were tested: quantile normalisation, deltaCt normalisation, and geometric mean normalisation. Comparing the different normalisation methods, and after the removal of 3 patient samples, the quantile normalisation method performed best at reducing the variation between the data points and was used for the downstream analysis of differential expression. This is illustrated in RT values above 38 and below 14 were defined as unreliable. Clustering analysis of normalized miRNA data identified two major sample groups that correlated with sample collection dates  of the BMA package was run using the 16 miRs of interest and the information about patient response to treatment (good or bad) as a vector, with the following parameters: The BiomaRt package  in R wasCytoscape was used to produce the interaction network between some of the two miRNA targets found to be significant. AKR1C3 was considered as the gene of interest to start the network. The first neighbours of this gene were retrieved, resulting in only one other gene.https://github.com/GamaPintoLab/Lim-et-al-2023.git.R scripts used in this study are available at Fifty-two patients were prospectively recruited into this study from 2014–2017. The median patient age was 62 years, with more than two-thirds being male. The majority of patients were diagnosed with stage T3 and node-positive locally advanced rectal cancer. More than two thirds of the patients were of a good performance status. Complete pathological response was seen in 18%. The median follow up was 2.7 years, at which time 21% had recurred. TM instrument and CTC enumeration kit for the 52 patients are shown in A typical image of CTCs captured and the number of CTCs captured and identified using the IsofluxA three-tiered selection approach was applied to identify 106 candidate miRNAs of interest. The miRNAs, along with the approach used to select the miRNAs and accompanying references, as well as a data summary, are listed in The panel of selected miRNAs used in this study were assessed for differential expression during neoadjuvant treatment as described in the methods. The miRNAs that significantly changed over the course of treatment are listed in The differential expression analysis between the time-points  revealed six miRNAs to be differentially expressed between during treatment and post-treatment time-points. In addition, 12 miRNAs were differentially expressed between baseline and during treatment. Of these, three miRNAs  overlapped between the two group comparisons and are shown italicised and in bold in p = 0.048), illustrated in We next performed a differential expression analysis comparing good responders (TRG 0 and 1) and poor responders (TRG 2 and 3) for each of the time-points. Only one miRNA, hsa-miR-483-5p, was found to be differentially expressed in the post-treatment time-point between good and poor responders, with a fold change of 8.48 , have reported up to 84% having CTCs, the majority consisting of a non-metastatic CRC cohort of which a subgroup consisted of rectal cancers [Presence of CTCs was found in 73% of the patient cohort, which consists of non-metastatic patients. This is a high level for early-stage cancer and is consistent with the IsofluxSearchTM . Publica cancers . Another cancers .TM found 19% of patients had ≥1 CTC at baseline per 22.5 mL blood [CTCs have been found to be higher in rectal cancers treated with neoadjuvant chemoradiation compared to patients who have not received this therapy and there have been variable findings of CTC change with chemoradiation ,23,24,25We found an overall decrease in CTC numbers over the treatment course, though there is clear heterogeneity between patients. Overall, CTC counts appear to decrease between baseline and during treatment, as well as between baseline and post-treatment with mean CTC numbers post-treatment being slightly higher than during treatment, but lower than at baseline. This is largely consistent with the literature which has reported a fall in CTCs during treatment. Differences in isolation techniques likely account for differences in positivity rate. Importantly, we also looked at three time-points, and tracked CTC change over the treatment course. Most studies have focused on one or two time-points. The increase in CTCs we observed with tumour treatment is similar to another study that also looked at three time-points, albeit all post-treatment. The authors also observed an increase in CTCs within a week of surgery which fell after 6 months. It can be hypothesized that tumour disturbance with treatment or surgery may result in CTC dissemination which results in a transient rise .To our knowledge, there is no literature looking at the miRNA expression profiles of these CTCs and associated lymphocytes. We found that miRNA expression significantly changes during chemoradiation, with 12 differentially expressed miRNAs between baseline and during treatment. Three of these were also differentially expressed from during treatment to post-treatment. Importantly, of these miRNAs, there was a strong correlation between hsa-miR-19b with tumour response, suggesting that low levels of this miRNA correlate with a good response to chemoradiation.hsa-miR-95, hsa-miR-10a, and hsa-miR-16-1 have all been implicated in colorectal cancer carcinogenesis. These three miRNAs were found in our study to be significantly differentially expressed across treatment time-points. miR-95 is thought to target sorting nexin 1 (SNX1) and promotes cell proliferation and oncogenesis . miR-95-This finding of miR-19b and correlation with tumour response is supported by other studies in the literature, mainly in solid tissue ,32. miR-IGF2 and carcinogenesis, possibly making it a potential diagnostic biomarker [Another promising miRNA candidate is miRNA hsa-miR-483-5p, which was differentially expressed between good responders and poor responders and showed up as an independent variable in all our Bayesian models. This is consistent with the literature of this miRNA in solid tissue, where upregulated miR-483-5p was found in TRG1 patients (good responder) compared to TRG > 1 (poor responder) patients as classified by the Mandard TRG classification . Similariomarker .The gene ontology annotations for these two miRNAs are shown above and they may play a role in the Wnt and MAPK pathways. miR-483-5p is believed to regulate AKR1C3. The upregulation of hsa-miR-483-5p in responders when compared to non-responders could indicate that the targeting of AKR1C3 is contributing to a better response to the drug, which makes this miRNA a potential clinically useful predictor of response to treatment.In summary, the additional information from liquid biopsies measured during treatment of LARC is invaluable, as response prediction during chemoradiation may serve to either intensify or de-escalate treatment. This is particularly relevant due to the move toward total neoadjuvant therapy and the watch and wait approach, potential alternatives to shift the traditional paradigm of chemoradiation and surgery ,3. The nOur data show that CTCs were present in the vast majority of non-metastatic LARC patients, and fell during chemoradiation, although there was heterogeneity between patients. To our knowledge, this is the first study to report miRNA expression profiles from isolated CTCs in LARC rather than from solid tissue, and we found that expression changes during treatment, with three miRNAs being differentially expressed across the three time-points, and a further twelve miRNAs were differentially expressed in pairwise time-point comparisons. miR-19b-3p and miR-483-5p correlated with good response, the latter also found to be differentially expressed between good responders and poor responders. These findings are largely supportive of the literature and the putative targets of these miRNAs. Thus, they represent potential predictive biomarkers as well as a potential strategy to sensitise tumour cells to treatment.


The COVID-19 pandemic substantially disrupted healthcare utilization patterns, globally. South Korea had been praised widely in its efforts to contain the spread of the pandemic, which may have contributed to a significantly smaller reduction in healthcare utilization compared to neighboring countries. However, it remains unknown how the COVID-19 pandemic impacted utilization patterns across population sub-groups, particularly vulnerable patient groups in South Korea. This paper quantifies the changes in healthcare utilization attributable to COVID-19 and the COVID-19 vaccination by sub-groups.An interrupted time series analysis was conducted to examine the impact of COVID-19 on healthcare utilization in South Korea from January 2016 to December 2022 using aggregated patient-level data from the national health insurance system that accounts for 99% of all healthcare services in South Korea. We applied negative binomial models adjusting for seasonality and serial correlation. Falsification tests were conducted to test the validity of breakpoints. Stratified analyses by type of healthcare services, age, sex, income level, health facility type, and avoidable/non-avoidable hospitalizations was performed, and we assessed differences in utilization trends between population groups across three phases of the pandemic.In early 2020, the COVID-19 pandemic caused a reduction in monthly volume of outpatient utilization by 15.7%  and inpatient utilization by 11.6% . Most utilization recovered and rebounded to pre-COVID-19 levels as of December 2022 although variations existed. We observed heterogeneity in the magnitude of relative changes in utilization across types of services, varying from a 42.7%  decrease for pediatrics, a 23.4%  reduction in utilization of public health centers, and a 24.2%  reduction in avoidable hospitalizations compared to the pre-pandemic period. Contrary to global trends, health utilization among the elderly population (65 and older) in South Korea saw only marginal reductions compared to other age groups. Similarly, Medicaid patients and lower income groups experienced a smaller reduction compared to higher income groups.The impact of the COVID-19 pandemic on healthcare utilization in South Korea was less pronounced compared to the global average. Utilization of vulnerable populations, including adults over 65 years old and lowest-income groups reduced less than other type of patients.No funding. COVID-19 substantially disrupted the normal patterns of healthcare utilization globally, with a median reduction of 37.2% between the pandemic and pre-pandemic period and ranging from −19.8% to −50.5%.South Korea has been praised widely in its efforts to contain the spread of the pandemic with one of the lowest mortality rates among Organization for Economic Co-operation and Development (OECD) countries even at the height of the Omicron wave. Successful containment strategies possibly contributed to a significantly smaller reduction in healthcare utilization compared to neighboring countries.Recent analysis showed that the number of personal hospital visits still decreased by 11.9% in 2020 compared to the previous year. It remains unknown how the pandemic impacted utilization patterns across population sub-groups, particularly vulnerable patients in South Korea.In terms of the sources, we have referenced all literature databases available online. We also crosschecked our storyline and data from the NHIS reports and databases for triangulation. We focus on data collected post MERS (2015) to remove any impact of MERS on healthcare utilization, thus the timeframe is from 2016.To our knowledge, this is the first study to examine how Korea's healthcare utilization evolved due to COVID-19 to this granular level. The study is comprehensive as it covers the entire population across 7 years, stratified by sub-group categories, and uses a robust statistical method.The impact of the COVID-19 pandemic on healthcare utilization in South Korea was less pronounced compared to the global average. Utilization of vulnerable populations, including adults over 65 years old and lowest-income groups reduced less than other type of patients.It is important for policymakers to understand causes of utilization changes in population groups that were significantly impacted to make decisions on health policies for better and fairer healthcare systems and to adequately prepare and respond to a future pandemic. Our study provides new insight into South Korea's ‘relative’ preservation of healthcare utilization and may help policymakers and researchers in other countries to consider strategies that could curtail about the impact of COVID-19 and that of future pandemics on healthcare utilization.,The Coronavirus disease COVID-19) pandemic substantially disrupted the normal patterns of healthcare utilization globally, with a median reduction of 37.2% between the pandemic and pre-pandemic period, and ranging from −19.8% to −50.5%.9 pandemi,Restrictive measures to control the spread of the COVID-19 pandemic caused disruption to access to healthcare services particularly among vulnerable population groups. A systematic review across 20 countries estimated healthcare utilization was reduced by more than one-third,,,,Several factors could explain South Korea's smaller reduction of healthcare utilization. More effective management and control of COVID-19 is a leading explanation.This study examines two interrelated research questions: (i) did changes in healthcare utilization attributable to COVID-19 differ by sub-groups, including age, sex, health facility type, income level as proxied by insurance premiums, types of services (departments), and avoidable/non-avoidable services? We hypothesized that heterogeneity in the magnitude of relative changes in utilization existed across different sub-groups. And (ii) was the achievement of high rates of COVID-19 vaccination associated with changes in healthcare utilization across population groups? We hypothesized attaining World Health Organization (WHO)'s recommended 70% vaccination coverage (full doses) increased the level of healthcare utilization. The paper explores the potentially unequal access of health services among different socio-economic status groups through stratified analysis. We also seek to explore other possible reasons for the smaller than average health care utilization reduction besides lower incidence rates of COVID-19 cases in South Korea.Our primary source of data on healthcare utilization comes from monthly aggregates of medical claims data collected by the National Health Insurance Service (NHIS) in South Korea from January 2016 to December 2022 (NHIS-2022-1-788). We focus on data collected post MERS (2015) to remove any impact of MERS on healthcare utilization. We compared demographic and socioeconomic characteristics, including patient age, health facility type, income level based on premium contributions (interchangeably used as ‘income level’ in the paper), types of services (departments), and avoidable hospitalizationsWe conducted an exploratory analysis of aggregated monthly claims data. Healthcare utilization is defined as the sum of outpatient visits and inpatient utilization per month. Re-visits and re-admissions for the same patient in each month were recorded as separate visits and contributed to the overall number of visits. Outpatient utilization is defined as the sum of outpatient, emergency department, and pharmacy visits. In South Korea, pharmacy visits are counted as a separate outpatient encounter utilized when a patient visits a health facility and fills a prescription. Trends were plotted to visualize changes in health services utilization patterns disaggregated by population subgroups, to understand any significance and outliers.,25A set of stratified interrupted time series (ITS) analyses were performed to examine the impact of COVID-19 on healthcare utilization in South Korea from 2016 to 2022. To find the associations between COVID-19 and healthcare utilization, we applied a count data model of utilization events. We applied negative binomial regression models instead of Poisson models accounting for seasonality. This allowed the conditional variance of the outcome variable to be greater than its conditional mean, thus controlling for observed overdispersion in the data.We divided the time series into a pre-COVID-19 phase and then two phases of the COVID-19 period in order to fit a piecewise regression model with three segments. The ITS model included two breakpoints to assess the impact of both the first arrival of the first cases of COVID-19 and the era when vaccination coverage became prevalent in late 2021. The first breakpoint (‘onset of COVID-19’) was set at January 2020, given that the first case reported in South Korea was in January 2020 and when the government raised the Crisis Alert Level from 1 to 4 (highest). The second breakpoint (‘recovery period’) was set as October 2021 when the vaccination rate (fully vaccinated) achieved 70% coverage across the general population.xtbreak test command in Stata which tests for multiple breaks at unknown break dates.,To assess the robustness of the ITS model, we conducted two approaches using a falsification test drawing from techniques in both time series analysis and the regression discontinuity literature.Please, refer to supplementary material B for detailed timeline of events during the pandemic. Stratified analyses by sex, age, income-level, department, health facility type, and avoidable hospitalizations were conducted to assess potential differences in the utilization responses across sub-group variables (SGV).i at time tm. The following seasonally adjusted piecewise regression equationThis study was exempt from the approval by the Institutional Review Board (IRB) at Seoul National University (IRB No. E2203/003-001).The total number of patients in the analysis increased from 51,522,134 in 2016 to 51,948,854 in 2022. Based on the monthly aggregated data, the characteristics of patients who used healthcare services are presented in Monthly average outpatient utilization before COVID-19 was 107,352,911  and 99,209,540  between Jan 2020 and Dec 2022. This translates to approximately 2.1 utilization episodes per capita pre-COVID-19 to 1.9 per capita post-COVID-19. Per capita utilization is only available for total utilization and utilization stratified by age and income level.From 2016 to 2019, we observed steady annual increases ranging from 0.5% to 3% from the previous year; however, there was a 8.1% and 4.6% unadjusted monthly reduction in total outpatient and inpatient utilization per capita post-COVID-19, respectively, compared to pre-pandemic levels , Table 3Large variations due to COVID-19 on health utilization by age, health facility, income level and departments were observed. The youngest group (0–6-year-olds) health utilization decreased the most after COVID-19 for both outpatients and inpatients episodes per capita by 33% and 20.6%, respectively. Reductions of lesser magnitude were seen for ages 7–18. We also observe the highest utilization per capita for the youngest and eldest group with approximately 4 visits per capita.We also observed higher reduction in women compared to men. In addition, utilization by type of health facilities varied. Higher tier health facilities such as tertiary hospitals and clinics increased total utilization, while public health centers, which provides primary and essential healthcare services, decreased by 53% compared to pre-pandemic levels. Long-term care facilities experienced a 44.4% increase post-COVID-19.Model findings reflect a statistically significant reduction of 15.7%  and 11.6%  for outpatient and inpatient services, respectively, comparing pre-pandemic and post-pandemic levels . During Female rates of visiting outpatient services deceased slightly more than rates for males in January 2020 compared to pre-pandemic levels . HoweverOlder adults (65 years old and above) had the least impact on both outpatient and inpatient utilization services for post-COVID-19. For ages 65–74, utilization decreased by just 5.7% for outpatient services with a 4.9% decrease for inpatient services . ReflectWe also observed variations across insurance premium contribution levels which are partly reflective of income level. All insurance contribution groups reduced their outpatient and inpatient utilization services in January 2020 as shown in The decreases of outpatient health services were the greatest in the pediatrics department and otorhinolaryngology (ENT) department in January 2020 compared to pre-pandemic levels . HoweverA 23.4%  and a 22.7%  statistically significant reduction in outpatient visits at public health centers and clinics, respectively, were observed in January 2020 . The impInpatient services can be divided into avoidable and non-avoidable hospitalizations. A 24.2%  and a 8.1%  statistically significant reductions were observed post-COVID-19 for avoidable hospitalization and non-avoidable hospitalization utilizations, respectively . In OctoFalsification tests examined whether the ITS results were sensitive to the choice of breakpoints using two approaches.Our study investigated the impact of changes in healthcare utilization attributable to COVID-19 and the COVID-19 vaccination by stratification including age, health facility type, income level, types of services, and avoidable/non-avoidable hospitalization. Findings were derived from the most comprehensive source of healthcare data available in South Korea. We find significant reductions in both monthly volume outpatient (−15.7%) and inpatient health service utilization (−11.6%) due to COVID-19 in early 2020 with similar trends observed for both adjusted and unadjusted figures. Possibly linked to South Korea's effective management and control, effective administration of COVID-19 vaccines, and health system resiliency, even at the peak of the Omicron surge, the total healthcare utilization rebounded above pre-pandemic levels as of December 2022.,,We observed wide heterogeneity in the magnitude of relative changes in utilization across different types of services, age, sex, income level, health facility types, and avoidable/non-avoidable hospitalizations. This includes large variations in the changes in service utilization by income levels, with the least reduction shown for Medicaid patients and lower income groups compared to higher income groups. However, the fastest increases occurred for higher income group after October 2021. The youngest age groups experienced the largest drop possibly due to parents’ fear of infection,,,,,This reduction of healthcare utilization during the pandemic can be attributed to a myriad of factors, which could stem from changes in health seeking behavior due to fear of cross-infection at the point of care, strict social distancing and isolation policies, and suspension of schools.Groups of high vulnerability such as the elderly and those with limited income had protection. Contrary to global trends, outpatient and inpatient health care utilization among the elderly population (65 and older) in South Korea experienced the least reduction compared to other age groups. Although there were reductions in long-term care for the elderly, the preservation of acute care for the elderly is notable. Other commentators have credited the country's effective management of medical systems to along with a strong COVID-19 containment policy in healthcare settings.Most health service utilization rebounded to pre-pandemic levels as of December 2022 and possible factors include the high vaccination rate, the lifting of almost all levels of social distancing measures, and deliberate efforts to maintain the continuity of health services in the country. It is not possible for this analysis to untangle relative impact of the multiple related factors working together to restore service utilization in late 2022.,,Although further research is needed to better understand the full health effects of COVID-19-related disruptions in utilization, it is well known that avoidance of and delayed access to health services was associated with poor health outcomes and may cause the occurrence and worsening of diseases and complications.To our knowledge, this is the first study to examine how Korea's healthcare utilization evolved due to COVID-19 to this granular level. The study is comprehensive as it covers the entire population across 7 years, stratified by sub-group categories, and uses a robust statistical method. It is important for policymakers to understand causes of utilization changes in population groups that were significantly impacted to make decisions on health policies for better and fairer healthcare systems and to adequately prepare and respond to a future pandemic. Our study provides new insight into South Korea's ‘relative’ preservation of healthcare utilization and may help policymakers and researchers in other countries to consider strategies that could curtail about the impact of COVID-19 and that of future pandemics on healthcare utilization.The results are subject to three important limitations. First, the data is aggregated which may potentially mask important nuances that may be present in the underlying individual level data. Second, the data did not disaggregate between COVID-19 services and non-COVID-19 services, thus we were not able to explore the direct contribution of COVID-19 caseloads to care-seeking. Third, there is a possibility of data collection errors and delay in reporting, which may have impacted the results. For instance, NHIS reported that November to December 2022 medical utilization data may be subject to errors due to incomplete validation from the verification department. Fourth, the health insurance claims data will not include utilizations that are not covered by health insurance.In conclusion, our study showed that COVID-19 significantly impacted healthcare utilization with a strong rebound. The study also showed heterogeneity in the impact among certain sub-groups population, but a remarkable ability to protect the access to care of vulnerable groups like the elderly and those with lower income. Preserving the mechanisms behind the institutional capacity of the country's preparedness and response to the pandemic should be a key interest for South Korean policymakers. Those in the global community eager to learn strategies and policies to shield vulnerable groups during future crises would also benefit from more detailed attention to the South Korean record to prepare for potential future pandemics.Katelyn J. Yoo conceptualized and wrote the first draft, conducted the analysis, analyzed and interpreted data, and edited and reviewed drafted materials.YoonKyoung Lee assisted literature review, conducted data analysis and interpretation, and reviewed drafted materials.Seulbi Lee assisted with data collection and formatting, reviewed all citations and reviewed drafted materials.Rocco Friebel contributed to shaping the storyline, edited and provided feedback on data interpretation and all drafts.Soon-ae Shin led the collection of the data and reviewed drafted materials.David Bishai contributed to study design, provided feedback on data interpretation and edited and provided feedback on all drafts.Taejin Lee contributed to study design, provided feedback on data interpretation and provided feedback all drafts.Healthcare utilization data is deemed “sensitive” data in South Korea by the Personal Information Protection Act (PIPA). The data cannot be publicly shared because of data privacy restriction which protects patient confidentiality. Access to data is possible only once approval from the South Korean government and National Health Insurance Service (NHIS) has been obtained.The Lancet Group takes a neutral position with respect to territorial claims in published maps and institutional affiliations.The authors whose names are listed immediately above certify that they have NO affiliations with or involvement in any organization or entity with any financial interest , or non-financial interest  in the subject matter or materials discussed in this manuscript.


COVID-19 can affect many organ systems, including the CNS, with symptoms of altered mental status and seizures. We present a case of a 30-year-old man with cerebral palsy who developed seizures after a COVID-19 infection. Admission labs were remarkable for hypernatremia, and elevated creatine kinase, and troponin levels as well as creatinine above baseline. MRI was performed demonstrating a small, evolving acute/subacute abnormality in the midline splenium of the corpus callosum. An EEG showed moderate to severe abnormalities with low-voltage delta waves. The patient was treated with medication and advised to follow up with a neurologist. One month later, no residual CT abnormality corresponding to the previously reported lesion in the midline splenium of the corpus callosum was observed. Although epilepsy is a common finding in patients with cerebral palsy, the complete lack of seizure activity throughout this patient's early life, coupled with previously unremarkable brain imaging, further supports our claim that his recent onset of seizures was directly related to COVID-19. This case highlights the possibility of new seizures in patients with pre-existing neurological conditions after COVID-19 infection and emphasizes the need for more research. The novel COVID-19 (SARS-CoV-2) has caused widespread disruption for the past three years, leaving many questions unanswered. Some patients continue to suffer from the effects of 'Long COVID' where symptoms persist after the resolution of the acute infection. In some cases, these symptoms may include rare neurological complications. Kincaid et al. report a patient with 'Long COVID' returning to the hospital six days following his discharge with new onset seizure activity reportedly unexplained by any other causes [Herein we present a case of a 30-year-old black male with cerebral palsy who developed seizures shortly after a COVID-19 infection. Epilepsy is common among patients with cerebral palsy; however, it typically manifests within the first two years of life. Thus, here we suggest that 'Long COVID' may likely be the cause of new-onset seizures in this patient. The purpose of our report is to increase awareness of a rare but potentially debilitating complication and provide information on the diagnosis and management of COVID-19-related seizures.A 30-year-old black male with cerebral palsy and previous hospitalization for COVID-19 presented to the ED on post-discharge day five due to focal tonic-clonic seizure with impaired awareness. On the previous visit, a CT head was performed for evaluation of acute encephalopathy, which was negative for any acute intracranial abnormality. The patient was later discharged with a single dose of Paxlovid.He then returned to the ED five days later with reports of continued high-grade fevers (101-103 °F) refractory to antipyretic agents and subsequent tonic-clonic seizures associated with tongue biting. Seizure episodes reportedly lasted 20 minutes and were bilateral tonic-clonic movements occurring in the upper extremities. Seizure activity was controlled with 5 mg midazolam administered by EMS en route to the hospital.On arrival at the ED, the patient was postictal, febrile to 104 °F, and tachycardic. Admission labs were remarkable for hypernatremia, creatine kinase, and troponin levels. Serum creatinine was also noted to be above baseline  which can lead to lethargy, weakness as well as seizures in severe cases as the serum sodium concentration approaches > 158 mmol/L. In our patient in the context of a prior COVID-19 infection with continued high-grade fevers 101-103 F), hypernatremia may be occurring secondary to dehydration. However, in a case series of 12 critically ill COVID-19+ patients, hypernatremia (151-159 mmol/L) was found to persist throughout the ICU stay but was not correlated with severe neurological symptoms  F, hyper,5.6 mmol/L Previously reported cytotoxic lesions of the corpus callosum (CLOCC) have occurred in various medical conditions, including infections, trauma, and malignancy . In two Additionally, the transient nature of cytotoxic lesions of the corpus callosum (CLOCC) increases the risk for a misdiagnosis of cerebrovascular accident (CVA)/transient ischemic attack (TIA) and subsequent treatment with medications which may increase bleeding risk . To makeIndividuals with cerebral palsy have a significantly higher risk of developing epilepsy when compared to the general population, with seizure rates reaching 20%-45% in children with CP . In thesThe above case report further emphasizes the need for continued research involving atypical presentations of COVID-19. COVID-19 has the ability to affect many organ systems including the CNS and can manifest with symptoms of altered mental status and/or seizures. Initial diagnostic testing may include cerebral imaging modalities such as MRI or CT of the head, as well as EEG, and cerebrospinal fluid analysis. Diagnostic testing can help to establish patient prognosis and guide further therapy. Although glucocorticoids and immunomodulatory agents have been proven to reduce mortality in patients with dyspnea and supplemental oxygen use, their benefits in the management of COVID-19 encephalopathy remain unclear.While prior studies have explored the potential association between cytotoxic lesions in the corpus callosum and COVID-19, our patient's condition was further complicated by cerebral palsy. The symptoms of COVID-19 in neurologically impaired patients may vary, and it is important for physicians to be mindful of these changes as they can influence future treatment plans. More information is needed to better understand and determine the neurologic impact of COVID-19 infection.


Typical segmentation algorithms operate at low resolutions without fully exploiting multi-granularity visual features. Moreover, several related studies do not release their datasets that are key for the research on deep learning-based solutions. We propose a novel end-to-end retinal layer segmentation network based on ConvNeXt, which can retain more feature map details by using a new depth-efficient attention module and multi-scale structures. In addition, we provide a semantic segmentation dataset containing 206 retinal images of healthy human eyes (named NR206 dataset), which is easy to use as it does not require any additional transcoding processing. We experimentally show that our segmentation approach outperforms state-of-the-art approaches on this new dataset, achieving, on average, a Dice score of 91.3% and mIoU of 84.4%. Moreover, our approach achieves state-of-the-art performance on a glaucoma dataset and a diabetic macular edema (DME) dataset, showing that our model is also suitable for other applications. We will make our source code and the NR206 dataset publicly available at ( The retina is often referred to as the “window to the body,” as the early stages of many chronic diseases are associated with structural changes in the tissues of retinal layers . Since OManual segmentation of retinal layers, traditionally an early method, has been labor-intensive, expensive, and challenging to standardize among different specialized ophthalmologists. Hence, automatic segmentation methods for retinal layers have become indispensable. Thanks to the rapid advancements in deep learning-based techniques, computational imaging approaches have become increasingly adept at automatically addressing this progression. These techniques rely on specialized datasets corresponding to the task to function reliably  images currently exist online. Since the introduction of the fully convolutional network (FCN)  employed in our proposed framework is based on an enhanced version of the convolutional block attention module (CBAM) . The OCT machine uses a superluminescent diode with a wavelength of 840 nm as its optical source. The images are captured at a resolution of 500 × 750 pixels. We use this dataset for semantic segmentation, which allows us to study the variations in retinal layer thickness in healthy human eyes.The NR206 dataset originates from 206 optical coherence tomography (OCT) retinal images of normal, healthy human eyes that are part of the OCTID  the glaucoma dataset  and conduct 4-fold cross-validation experiments on it. For the other two public datasets, we set the image size to  for the glaucoma dataset  denotes the output probability of category xi. Specifically, when a retinal image is processed by a segmentation model, each pixel is associated with m values , and each value represents the output probability of each category. We translate these values so that the minimum value is greater than 0 and the sum of these m values is 1. The transformed values are p (xi), where In our segmentation task, each pixel is associated with multiple category output probabilities. We use the entropy measure  the impact of various feature backbones on the segmentation performance and 2) the role of the DE-CBAM module on the whole framework.We presented a novel multi-scale end-to-end network for improved retinal layer segmentation in normal healthy human eyes. Our network incorporates a state-of-the-art attention module to efficiently utilize feature information and utilizes a ConvNeXt-based backbone for accurate segmentation. In addition, we provide a semantic segmentation dataset comprising 206 retinal layer OCT images of healthy human eyes, with each image annotated into nine classes. The dataset has an average percentage of annotated pixels in the retinal layer of 14.82%, excluding the background. This dataset is readily usable without requiring any pre-processing steps. We validate our approach on the NR206 dataset and a glaucoma dataset, demonstrating superior segmentation performance compared to other state-of-the-art methods. Our approach achieves an average Dice score of 91.3% and mIoU of 84.4% on the NR206 dataset and similar excellent performance on the glaucoma dataset. Furthermore, we evaluate our method on a DME dataset to demonstrate its generalization capability, achieving the best performance with a smaller number of parameters. In future research, we suggest exploring the application of retinal layer segmentation in the early detection of ophthalmic diseases. This field holds significant potential for improving disease diagnosis and treatment monitoring in ophthalmology.


Substance use has been one of the most alarming public health problems worldwide, particularly among younger generations.This study evaluated the effectiveness of a web-based substance use prevention intervention targeted at adults aged 20-29 years.The intervention materials comprised 5 sets of infographics and 1 animation, all of which focused on mixed themes: (1) the concept of substance use and its harmful effects on health; (2) misinformation regarding new psychoactive substances; (3) regulation of illicit drugs, particularly marijuana; (4) the brain disease model of addiction; (5) critical thinking skills that improve health literacy; and (6) decision-making and communication skills that help people refuse illegal drugs. The study assigned eligible participants into experimental and control groups on the basis of the parity of their participant numbers. These participants completed web-based baseline and follow-up questionnaires that assessed their knowledge, behavioral intention, self-efficacy, and life skills related to substance use prevention. Knowledge was assessed using 8 questions concerning understanding of substance use harms and the regulation of illicit drugs. Behavioral intention and self-efficacy were assessed using 5-point Likert-type scales. Participants’ ability to apply life skills to avoid substance use was assessed using 3 testing scenarios regarding substance use. The study used generalized estimating equations to examine the intervention’s effectiveness.P<.001), behavioral intention (P<.001), and self-efficacy (P<.001) but not their life skills (P=.61) related to substance use prevention. Participants in the experimental group responded to a satisfaction survey with positive feedback on the intervention.A total of 1065 participants  completed the intervention and questionnaires in 2019. The average ages of the experimental and control groups were 25.68 (SD 2.71) and 25.66 (SD 2.69) years, respectively. The study observed no significant differences in the demographic variables between the 2 groups. The results of the generalized estimating equation analyses indicated that the intervention significantly improved participants’ knowledge (The web-based intervention was effective in improving participants’ knowledge, behavioral intention, and self-efficacy concerning substance use prevention. The findings support continued efforts to use web-based interventions to prevent substance use among young adults. According to the 2020 World Drug Report, drug use has increased rapidly worldwide over the past 2 decades, particularly among younger generations . The 202The internet has given rise to a new platform for substance use prevention education. Web-based interventions have the potential to increase participants’ understanding of illegal drugs and their risks with comparable effectiveness to that of traditional classroom lectures. Furthermore, the application of web-based interventions may assist school health education and increase students’ willingness to learn . The effStudies have attempted to leverage web-based interventions for substance use prevention education and shown mixed evidence ,11. TheoThe study selected research participants from young adult internet users aged 20-29 years in Taiwan. The internet use rate reached 100% among a representative sample of Taiwanese people aged 20-29 in 2020 . The stuThe study procedure and materials were approved by the institutional review board of the National Taiwan Normal University (#201903HM009).The study based the design of the intervention materials on a literature review, needs assessment, behavioral theories, and meetings with experts. The needs assessment stage involved quantitative and qualitative methods. The quantitative component involved a web-based survey of the learning needs and interests related to substance use prevention of 357 participants aged 20-29 years. The qualitative component involved the implementation of in-depth interviews with young substance users and health care professionals involved in addiction treatment to understand their motives, experiences, and reflections of substance use as references for compiling the intervention materials.The study primarily based the intervention content design on need assessment results and behavior theories, including the health belief model , theory This study used a quasi-experimental design, given that the implementation of random assignment was not feasible at baseline under resource constraints. All intervention activities were conducted on the web-based platform, which displayed the intervention materials and questionnaires. The study divided all eligible participants, after their completion of the baseline assessment, into experimental and control groups on the basis of the parity of their participant numbers, which they were assigned upon accessing the platform. The study guided participants in the experimental group to review all of the infographics and watch the animation, whereas the study asked those in the control group to watch a set of videos about reproductive health education. The study asked participants in both groups to complete a follow-up evaluation questionnaire immediately after participating in the preceding activities.Participants’ knowledge on substance use prevention was assessed using 8 questions concerning the understanding of substance use harms  and the regulation of illicit drugs . The study calculated the scores referring to the correct responses for each participant, with a higher score indicating a greater understanding. Behavioral intention, the participants’ self-rated likelihood of avoiding substance use, was assessed using a 5-point Likert-type scale comprising 4 items, such as “Please rate the likelihood of you refusing substance use if you are invited by friends to try using an additive substance.” Higher scores represented a stronger behavioral intention to avoid substance use. The self-efficacy measure also used a 5-point Likert-type scale with 4 items, such as “Please rate the level of confidence toward your ability to verify the online misinformation about using addictive substances.” Higher scores indicated greater confidence in the ability to resist substance use. Finally, the study assessed participants’ ability to apply life skills to avoid substance use, using 3 testing scenarios . The higher scores of correct responses indicated a better ability to apply life skills to prevent substance use in daily life. These measurements were developed along with the intervention content design on need assessment results and behavior theories.t test. The study used generalized estimating equations (GEEs) to examine whether the web-based intervention had improved participants’ knowledge, behavioral intentions, self-efficacy, and life skills concerning substance use prevention. The GEE method can be used to analyze repeated measures with non-normal response variables, and it can take into account the correlation of within-subject data.The study used SAS  to analyze the data. Characteristics and baseline data of 2 groups of participants were compared using an independent samples The average ages of all 1065 participants, the experimental group, and the control group participants were 25.67, 25.68, and 25.66 years, respectively. Both the experimental and control groups had a higher proportion of women than men . The study observed no significant differences in the demographic variables between the 2 groups, as displayed in t test indicated that the control group scored significantly higher (P<.05). In the follow-up test, the average scores of the control and experimental groups on the questions in the same section were 6.08 and 6.32, respectively. The study observed a significant difference between the 2 groups (P<.01), with the experimental group scoring higher  was found between the control (4.62) and experimental (4.56) group scores for behavioral intention. In the follow-up test, the mean scores of the control and experimental groups on the questions in the same section were 4.47 and 4.79, respectively, and the results of the t test revealed a significant difference (P<.01) between the 2 groups  between the control (4.70) and experimental (4.65) groups in their average self-efficacy scores for resisting substance use. In the follow-up test, the experimental group (4.74) outperformed the control group , such as featuring internet celebrities, providing additional animations, and displaying intervention messages on public transportation digital displays and screens. Similar strategies were deployed in cancer awareness campaigns targeting young women, and the campaigns made a positive impact as an effective public health communication initiative . Future Several limitations in this study should be mentioned. First, the participants took the follow-up test immediately after the intervention; thus, the long-term outcome or lag effect was not observed. Second, for the self-report questionnaires, using a single format of Likert-type items might have resulted in eliciting routine response patterns and socially desirable responses, which might have biased the results. Questions concerning substance use might be considered sensitive information by some participants. The study made the questionnaires anonymous to encourage truthful answers; however, social desirability bias could still have affected the responses. Third, factors affecting substance use behaviors are complicated, and social or cultural factors were not comprehensively addressed in this intervention, although these factors may also shape substance use behaviors. Finally, we recruited the study participants through convenience sampling, which may not be representative of the entire young adult population (aged 20-29 years) in Taiwan.In conclusion, this web-based substance use prevention intervention has the potential to enhance the knowledge, self-efficacy, and behavioral intention of young adults concerning substance use prevention. The high internet use rate among young people in Taiwan can facilitate the adoption of the web-based intervention. Web-based intervention promotion and diverse topics of materials  should be developed further to promote substance use prevention in young people.