Routine histopathological examination after cholecystectomy is costly, but the prevalence of unsuspected gallbladder cancer  is low. This study determined whether selective histopathological examination is safe.A comprehensive search of PubMed, Embase, Web of Science and the Cochrane Library was performed. Pooled incidences of incidental and truly incidental GBC  were estimated using a random‐effects model. The clinical consequences of truly incidental GBC were assessed.Seventy‐three studies (232 155 patients) were included. In low‐incidence countries, the pooled incidence was 0·32 (95 per cent c.i. 0·25 to 0·42) per cent for incidental GBC and 0·18 (0·10 to 0·35) per cent for truly incidental GBC. Subgroup analysis of studies in which surgeons systematically examined the gallbladder revealed a pooled incidence of 0·04 (0·01 to 0·14) per cent. In high‐incidence countries, corresponding pooled incidences were 0·83 (0·58 to 1·18), 0·44 (0·21 to 0·91) and 0·08 (0·02 to 0·39) per cent respectively. Clinical consequences were reported for 176 (39·3 per cent) of 448 patients with truly incidental GBC. Thirty‐three patients (18·8 per cent) underwent secondary surgery. Subgroup analysis showed that at least half of GBC not detected during the surgeon's systematic examination of the gallbladder was early stage (T1a status or below) and of no clinical consequence.Selective histopathological examination of the gallbladder after initial macroscopic assessment by the surgeon seems safe and could reduce costs. This meta‐analysis found that the incidence of truly incidental gallbladder cancer (GBC) was less than 0·5 per cent and decreased to less than 0·1 per cent when the surgeon performed a systematic macroscopic examination. At least 50 per cent of GBC that was not detected before or during surgery was of early stage and with no clinical consequences. Particularly in non‐endemic regions, selective histopathological examination after initital macroscopic assessment of the gallbladder by the surgeon seems safe and will likely result in significant cost and time savings.Open and palpate it Cholecystectomy for benign gallbladder disease is among the most frequently performed surgical procedures worldwide. For decades, it has been standard practice to send all gallbladder specimens for histopathological examination in order to exclude the presence of gallbladder cancer (GBC). This routine policy is costly and constitutes a significant workload for pathology departments, whereas the prevalence of unsuspected gallbladder cancer  is low. To save costs and reduce the workload of pathologists, selective histopathological examination has been proposedThis systematic review and meta‐analysis adhered to the Meta‐analysis Of Observational Studies in Epidemiology (MOOSE) guidelinesS1 (supporting information). The search results were imported into Covidence for further selectionA systematic literature search of PubMed, Embase, Web of Science and the Cochrane Library was conducted without language restriction and with a time limit set for studies published since 1 January 2009. The search was last updated on 1 June 2019. The search was performed with the assistance of a clinical librarian and included both medical subject heading (MeSH) terms and keywords. The search terms used were gallbladder (MeSH), cholecystitis (MeSH), cholecystectomy (MeSH), pathology (MeSH), gall bladder, histology, histopathology, routine, selective, carcinoma and cancer. Further details of the search can be found in All observational studies reporting the number of patients with GBC diagnosed during or after cholecystectomy performed for presumed benign gallbladder disease were eligible for inclusion. Studies that did not mention the total number of patients undergoing cholecystectomy, or the number of patients with GBC that was suspected or diagnosed before surgery, were excluded. In addition, studies that included specimens retrieved from cholecystectomy performed as an incidental procedure during other abdominal or pelvic operations were excluded. Preoperative gallbladder imaging was probably not done when the decision to perform a cholecystectomy was made during surgery, and this might have raised suspicion of GBC in these patients. Other exclusion criteria were: conference abstracts, no original data, no full text available, study performed in a centre with a selective policy of histopathological examination, studies that included post‐mortem specimens, and studies including specimens retrieved from cholecystectomies performed as part of more extensive, usually oncological, surgery (such as the Whipple procedure) rather than because of presumed benign gallbladder disease.Two reviewers independently screened the titles and abstracts of all retrieved references to identify studies that potentially met the inclusion criteria. Subsequently, the full texts of the remaining articles were independently assessed for eligibility by the same two reviewers. During all stages of the selection process, any conflict between the reviewers was resolved by discussion until consensus had been reached.For the purpose of this study, GBC included primary gallbladder malignancies regardless of histological type, gallbladder metastases and lymphoid malignancies. Incidental GBC was defined as GBC diagnosed during cholecystectomy or at histopathological examination, with no preoperative suspicion. Within this group, truly incidental GBC was defined as GBC diagnosed for the first time during histopathological examination without any suspicion before or during operation.Two reviewers independently extracted data from the included studies according to a predefined data extraction table. In case of disagreement, discussion took place until consensus had been reached. Collected data included study characteristics , the number of patients with (truly) incidental GBC and T category, age and sex of patients with truly incidental GBC, the consequences of truly incidental GBC for further management, and authors' recommendations about routine or selective histopathological examination. Study authors were contacted in case of missing data or uncertainty.Two reviewers critically appraised all studies according to the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence DataBecause of known variation in the geographical incidence of GBC, included studies were assigned to one the following two groups: studies from countries with a low incidence of GBC, and studies from countries with a high incidence of GBC. Allocation of studies into one of the groups was based on the age‐standardized incidence of GBC, as reported by GLOBOCAN 2018versus selective) and the costs of routine histopathological examination to achieve clinical benefit in one patient were evaluated.The main outcomes were: incidence of incidental GBC; incidence of truly incidental GBC; the ability of the surgeon to recognize GBC during surgery; and the clinical consequences of truly incidental GBC. Additionally, authors' recommendations regarding histopathological examination  were not reinterpreted by the authors as preoperative suspicion, when it was explicitly mentioned that GBC was not suspected before the operation. Studies that excluded patients with GBC suspected or diagnosed during surgery were not included in this analysis.To establish the incidence of truly incidental GBC, all studies reporting the number of patients with GBC that was not suspected or diagnosed before or during surgery were included. Surgical procedures that required conversion (for example due to dense adhesions) were not reinterpreted as intraoperative suspicious findings, if it was not explicitly mentioned in the article that the surgeon suspected GBC during surgery. Likewise, macroscopic abnormalities reported by the pathologist were not considered as intraoperative suspicious findings if the article did not explicitly mention that these were also detected by the surgeon and had raised suspicion during the operation.To assess the ability of the surgeon to recognize GBC during surgery, all studies reporting both the number of GBCs suspected or diagnosed during cholecystectomy (with or without opening the specimen) and the number of GBCs diagnosed during histopathological examination were included. Intraoperative sensitivity was defined as the fraction of incidentally detected cancers that were suspected by the surgeon during surgery.The clinical consequences of truly incidental GBC were grouped into seven categories: no further treatment; periodic surveillance; referral to oncologist (chemotherapy); referral to oncologist (unknown outcome); secondary surgery without 1‐year survival; secondary surgery with unknown survival ; and secondary surgery with at least 1‐year survival. In some studies, all patients were referred to the oncologist to discuss further management, regardless of tumour stage. When the oncologist decided that no additional diagnostic tests or any treatment were indicated, patients were assigned to the first group (no further treatment). Patients who received adjuvant or palliative chemotherapy were appointed to the third group (chemotherapy). If it was unclear whether the referral to the oncologist had led to additional diagnostic tests or treatment, patients were assigned to the fourth group (unknown outcome).To determine the value of systematic macroscopic examination by the surgeon, subgroup analyses were performed including the studies that specifically described that surgeons opened and systematically examined the mucosa of all removed gallbladders.To estimate the costs of routine histopathological examination to achieve clinical benefit in one patient, all studies that reported both the number of specimens with macroscopic abnormalities detected by the surgeon during systematic assessment of the gallbladder and the number of patients with truly incidental GBC were included. The analysis was based on the assumptions that: in the Netherlands, costs for histopathological examination are approximately €60 per gallbladder specimen; in a hypothetical situation of a selective policy, only specimens with macroscopic abnormalities are sent for histopathological examination; in the case of routine policy, all gallbladder specimens are sent for histopathological examination; and clinical benefit can be achieved only in patients with GBC of T1b status or above, as no further treatment is indicated for patients with less advanced GBC. To estimate the costs of a routine policy to achieve clinical benefit in one patient, the difference between costs made with a routine and selective policy was calculated and then divided by the number of patients with a normal‐looking gallbladder containing GBC of at least T1b category .I2 index and corresponding P value. All statistical analyses were performed using RStudio version 1.1.453 . The numbers of patients per category of clinical consequences of truly incidental GBC were reported as absolute numbers and percentages.The incidence of (truly) incidental GBC and the intraoperative sensitivity were meta‐analysed. Pooled percentages with corresponding 95 per cent c.i. were calculated using a generalized linear mixed model. A random‐effects model was used, considering the expected variation between the studies. Heterogeneity of the included studies was evaluated by calculating the Fig. In total, 937 studies were identified after removal of duplicates. Based on title and abstract, 135 studies were selected for full‐text assessment. Eighty articles were excluded because they did not meet the eligibility criteria Fig. 1. AfterFig. Fig. Meta‐analysis of 36 studies (129 059 patients) conducted in countries with a low incidence of GBC resulted in a pooled 0·32 (95 per cent c.i. 0·25 to 0·42) per cent incidence of incidental GBC Fig. 2. BasedFig. Fig. Based on 23 studies (50 264 patients), the pooled incidence of truly incidental GBC in low‐incidence countries was 0·18 (95 per cent c.i. 0·10 to 0·35) per cent Fig. 4. Meta‐Three studiesEighteen studies (38 598 patients) performed in countries with a low incidence of GBC reported both the number of GBCs suspected or diagnosed during cholecystectomy (with or without opening the specimen) and the number of GBCs diagnosed during histopathological examination  of the 176 patients did not receive further treatment. Twenty‐seven patients (15·3 per cent) were subjected to periodic surveillance. Fifteen patients (8·5 per cent) were referred to the oncologist and received chemotherapy. For a further 15 patients (8·5 per cent) who were referred to the oncologist, it was not reported whether treatment with chemotherapy was given. Survival data for these patients are provided in Table Details of truly incidental GBC, as reported by studies in which the surgeon systematically examined the gallbladder mucosa, are presented in In 20 of the 39 studies conducted in countries with a low incidence of GBC, the authors explicitly mentioned the recommendation regarding histopathological examination  and with no clinical consequence in half of the patients. Based on these results, selective histopathological examination of gallbladder specimens seems safe, at least in non‐endemic regions, and might result in a reduction of more than 90 per cent in the number of gallbladders submitted for examination.The main argument used for justification of a selective policy is that the diagnosis of incidental GBC is unlikely in gallbladder specimens without macroscopic abnormalities. Several studies90. In the present review, T category was known for 18 of the 24 patients who were diagnosed with truly incidental GBC despite systematic macroscopic examination by the surgeon. Twelve patients were diagnosed with GBC with T1a status or less, meaning that at least 50 per cent (12 of 24) of missed GBC was inconsequential. Histopathological examination revealed GBC of T1b status or above in the remaining six patients, of whom three had additional surgery. Some might state that these patients would have been undertreated if the surgeon had decided to refrain from histopathological examination. However, the clinical impact of secondary surgery on survival has been questioned. StudiesThe value of histopathological examination depends mainly on the therapeutic options arising from the diagnosis. No additional treatment is indicated for patients with cancer confined to the epithelium or mucosa of the gallbladder (T1a status or below), provided the resection margin is not involved. For patients with T1b, T2 or T3 GBC, re‐resection to remove any residual disease is recommended, unless this is contraindicated by advanced disease or poor performance statuset al.A few other systematic reviews have addressed the question of whether it is necessary to send all gallbladder specimens for histopathological examination. In a review by Jayasundara and de SilvaTo comment on the safety of a selective policy, information on the ability of surgeons to identify GBC during surgery is highly relevant. To the authors' knowledge, this is the first meta‐analysis to calculate pooled percentages for both incidental and truly incidental GBC. In addition, subgroup analyses were performed of studies in which surgeons performed a systematic macroscopic assessment of the gallbladder mucosa. The differences between these incidences showed the ability of surgeons to recognize GBC during surgery and the added value of a proper macroscopic assessment of the gallbladder mucosa for identification of GBC. Furthermore, reporting these pooled percentages separately enabled studies to be included as long as they provided the numbers required for at least one intended analysis, resulting in a total of 73 included articles. A final strength of this review is that it provides an estimation of the costs of selective and routine histopathological examination. Although the estimated costs were based on data from only seven studies, and should therefore be interpreted with caution, this review provides insight into the potential cost savings that might result from implementation of selective histopathological examination.This systematic review is subject to some limitations. Only 11 studies had a prospective design, so the conclusions of the review are based mainly on retrospective data with its inherent shortcomings. A moderate risk of bias was present in most studies, caused mainly by low sample sizes and insufficiently described histopathological methods. The latter limits the robustness of the results presented in this review, as inaccurate histopathological examination and staging of GBC might have biased all reported outcomes. Thirty studies reported on the ability of surgeons to recognize GBC before histopathological examination, but macroscopic examination was performed systematically in only nine, mostly small, studies. The clinical consequences of truly incidental GBC were described for only 176 (39·3 per cent) of all 448 patients. Owing to reporting bias, the actual proportion of diagnoses resulting in a change of postoperative management might be lower. As well as the presence of macroscopic abnormalities, there might be other reasons  for surgeons to send removed gallbladders for additional assessment by the pathologist. As a result, the number of patients in whom GBC would have been missed with a selective policy might be even lower than reported. Another consequence is that the actual reduction in number of specimens sent for histopathological examination will likely be less than the reported 92·6 per cent. Based on a few single‐centre studiesversus routine histopathological examination. Whereas more than half of the studies from low‐risk areas suggested a selective policy, the vast majority of authors from high‐risk areas concluded that all gallbladder specimens should be assessed routinely by the pathologist. Owing to the lack of a uniform protocol for pathological examination, considerable variation is observed in the way pathologists conduct the routine assessment of gallbladder specimensWhen considering a selective policy, one should be aware of regional and ethnic variation in the worldwide distribution of GBC. As expected, different incidences of incidental GBC were observed in the meta‐analyses of studies conducted in low‐ and high‐risk areas. This variation in geographical incidence was reflected in the various authors' recommendations on selective Some might fear the possible medicolegal consequences of a missed incidental GBC. However, the threat of litigation should not justify the overuse of diagnostic tools, especially if the intervention has no benefit for the patient and might potentially even cause harm  and involve substantial costs. Guidelines based on high‐level evidence are required to provide medicolegal protection for surgeons. To gain more evidence on safety and potential cost savings of selective histopathological examination, a large prospective cohort of patients is required. The FANCY studyAppendix S1: Supporting informationClick here for additional data file.


Despite an increase in national health care service utilization, entry into the health care system remains inequitable. This disparity in health care access disproportionately affects those experiencing homelessness. Because the homeless population faces significant financial and nonfinancial barriers, health care system engagement with these individuals must be reconsidered.This article will describe the piloting of an interprofessional model within an urban library to address barriers to health care access that homeless individuals face.The library's unique status as a community hub presents an opportunity for partnership in addressing this population's health care access issues. This community‐based model is the first recorded to utilize three distinct professions—nursing, social work, and library science—in a public library.The implementation of this pilot project resulted in a high retention rate of referrals to community health services for those unstably housed and facilitated a system of warm transfers. Although opportunities to improve generalizability exist, this initiative sets the stage for discussion around co‐location of health and social services in a nontraditional community‐based setting to achieve equitable access to health care. The goal of the team was to connect the public with information and awareness of low or no‐cost health resources. The team of professionals operated under a patron‐centered interprofessional model , received referrals to another in‐library professional and different health and social service agencies. The remaining 165 patrons (46%) either left before a referral was possible or declined the referral. Of the 193 patrons who were referred, 158 82%) received referrals to external community health or social service organizations, 20 (10%) patrons were referred internally to other in‐library professionals, and 15 (8%) patrons received both an internal and subsequent external referral. Of those 158 external referrals, 89 patrons (56%) identified as homeless or unstably housed while 69 patrons (44%) identified as stably housed. Of the 20 patrons who were referred within the library, eight (40%) identified as stably housed, while 12 (60%) identified as unstably housed or homeless. Of the 15 patrons who received both an internal transfer and a proceeding referral to an external community resource, four (27%) patrons identified as stably housed, while 11 (73%) identified as unstably housed. Table % receiveOf those patrons who received only external referrals, 57% (90 patrons) completed the external referral. When broken down into self‐identified categories of stably housed and unstably housed, the referral retention rate for those who were unstably housed was 87% (77 patrons) while the referral retention rate for those who were stably housed was 19% (13 patrons). Of those who received only internal referrals, the total referral retention rate was 85% (17 patrons). When split into housing status categories, 92% (11 patrons) of those unstably housed completed the internal referral while 75% (six patrons) of those who identified as stably housed completed the internal referral. For the patrons that received an internal and subsequent external referral, there was a 100% (15 patrons) referral retention rate for patrons who identified as stably housed and unstably housed or homeless.Table 2.1These programmatic outcomes are limited because the patron's referral experience was not captured and evaluated. Similarly, the likelihood with which they would return or send others to the referred agency was not recorded. Other predictors of the quality of these referrals, such as self‐reported health status, number of previous primary care visits, sociodemographic information, and experience with previous health care providers, were not assessed.It is also difficult to control for other variables that could have exacerbated or alleviated the difficulty with which the patron completed the referral. These confounding variables include assessments of the social support structure and previous engagement with the health care system. Further, the team was unable to collect pre‐intervention data, as most participants were unwilling to participate due to lack of relationship development. Future studies should consider the inclusion and analysis of pre‐intervention data and measures of patron and professional experience with the patron‐centered interprofessional model.2.2The homeless population is at risk for missing appointments, not receiving adequate outpatient care, utilizing the emergency room at high rates and having frequently no‐show rates  a more comprehensive range of referral resources, (2) greater accountability, and (3) a broader network with which the patron could build rapport. Further research and more focused data analysis are necessary to understand the relationship of increased referral retention rate and the implementation of the interprofessional model (Franklin, Bernhardt, Lopez, Long‐Middleton, & Davis, Although the rationale behind the high referral retention rate was not explicitly researched, the co‐location of services in the library setting was pivotal to the success of the model. The free and public nature of the library situates itself as a critical community access point. Furthermore, its reputation as a neutral resource‐filled space and its centrally convenient location makes it an anchor point, both physically and socially. This present paper creates further opportunity to bolster the efficacy of place‐based health care delivery (Dankawa‐Mullan & Perez‐Stable, The success of its outcomes is supported by reports of positive health outcomes with interprofessional teamwork, especially in the management of chronic diseases (Franklin et al., 3The pilot intervention and preliminary results of an increased retention referral rate demonstrate the opportunity to integrate creativity and collaboration when implementing methods to help patrons gain entry into and remain in the continuum of care. In a time where determinants of access to care are so numerous and variant, this pilot suggests that the use of multiple professionals across disciplines allows for the sharing of unique perspectives that can address these manifold barriers. Future interventions should consider innovative interprofessional models in addressing traditional health care access problems for vulnerable populations such as the homeless.The author has no conflicts of interest or relationships to disclose.


To develop and evaluate the classification accuracy of a computable phenotype for pediatric Crohn's disease using electronic health record data from PEDSnet, a large, multi‐institutional research network and Learning Health System.Using clinician and informatician input, algorithms were developed using combinations of diagnostic and medication data drawn from the PEDSnet clinical dataset which is comprised of 5.6 million children from eight U.S. academic children's health systems. Six test algorithms  that combined use of specific medications for Crohn's disease plus the presence of Crohn's diagnosis were initially tested against the entire PEDSnet dataset. From these, three were selected for performance assessment using manual chart review . Non‐cases were patients having gastrointestinal diagnoses other than inflammatory bowel disease. Sensitivity, specificity, and positive predictive value (PPV) were assessed for the primary case and primary non‐case algorithms.Of the six algorithms tested, the least restrictive algorithm requiring just ≥1 Crohn's diagnosis code yielded 11 950 cases across PEDSnet . The most restrictive algorithm requiring ≥3 Crohn's disease diagnoses plus at least one medication yielded 7868 patients . The most restrictive algorithm had the highest PPV (95%) and high sensitivity (91%) and specificity (94%). False positives were due primarily to a diagnosis reversal (from Crohn's disease to ulcerative colitis) or having a diagnosis of “indeterminate colitis.” False negatives were rare.Using diagnosis codes and medications available from PEDSnet, we developed a computable phenotype for pediatric Crohn's disease that had high specificity, sensitivity and predictive value. This process will be of use for developing computable phenotypes for other pediatric diseases, to facilitate cohort identification for retrospective and prospective studies, and to optimize clinical care through the PEDSnet Learning Health System. CPcomputable phenotypeEHRelectronic health recordICD9/10International Classification of Disease 9/10OMOPobservational medical outcomes partnershipSNOMED‐CTsystematized nomenclature of medicine—clinical terms1PEDSnet.org) is a multi‐institutional Learning Health System that aggregates electronic health record (EHR) data from eight of the nation's largest children's health systems,The era of using “Big Data” for research has resulted in many new opportunities to harness the power of electronic medical records and other complex data sets for improving child health. This is especially important because, compared to adults, there is a paucity of large, high quality data sources available for research on pediatric issues. Developed in 2014, PEDSnet  to describe a process for using EHR data to develop and evaluate discrete‐data computable phenotypes that could potentially be applied to other diseases and conditions; and (b) to develop and validate a computable phenotype specifically for Crohn's Disease to support case‐finding for future research.3The Children's Hospital of Philadelphia Institutional Review Board approved all study activities (approved protocol 16‐012878) and the other PEDSnet institutions relied on that determination. All analyses were completed using R 3.3.1 and Postgres 9.5.3.1The PEDSnet3.2Development of the Crohn's disease computable phenotype was done by defining a target case  and non‐cases that were lacking some or all the target criteria but were similar in other ways to cases, in order to optimize the algorithm's discriminant ability. For this work, we examined two non‐case algorithms—(a) patients with a gastrointestinal diagnosis other than Crohn's disease, ulcerative colitis or indeterminate colitis seen by any specialty or (b) patients with a diagnosis other than Crohn's disease, ulcerative colitis, or indeterminate colitis seen specifically by a gastroenterologist/in a gastroenterology clinic.Features to be tested in the various Crohn's disease algorithms were selected using disease expert and informatician input, with the goal of investigating the value of different data types. In order to evaluate different selection criteria, initially six alternative versions of the case algorithm were iteratively developed and assessed by cross referencing against a highly vetted, validated, national disease registry using data from one participating PEDSnet institution. This registry, supplied by the Improve Care Now network is considered a highly reliable source for identifying Crohn's disease patients as it represents a list of patients with a definitive diagnosis of Crohn's disease as determined by gastroenterologists, and in which the data undergoes rigorous external validation. Presence on this list was considered as an initial “gold standard” for selecting case algorithms to assess further, and this selection was based on computed positive predictive value (PPV) and sensitivity. The algorithms, ranging from one diagnosis (1d) through six diagnoses with medications (6 dm), identified the version that delivered the optimal tradeoff between sensitivity and specificity, rather than optimizing for one performance characteristic. This criterion was chosen because seeking a computable phenotype with this balance would permit the phenotype to be used for both case screening, without a high risk of missing true positives, and case selection, without a high risk of including false positives.Based on these results, four case algorithms were selected for further validity testing that included an assessment of the demographic distributions among the populations captured, and logistic regression models assessing the odds of a patient having an endoscopy or other radiographic exams focused on the gastrointestinal system . Based on the results from this further testing, one primary algorithm and one alternative algorithm for cases and one primary algorithm for non‐cases were chosen and externally validated across all sites using chart reviews. The small number of chart reviews for the alternative case algorithm was undertaken in order to understand discriminant validity between two closely related Crohn's disease algorithms.3.33.3.1Since Crohn's disease is a chronic condition with specific diagnostic codes and therapy, the starting criterion for case algorithms was physician‐recorded diagnosis. We used as a seed for assembling codesets the ICD‐9‐CM codes described by Ritchie et al.3.3.2https://www.nlm.nih.gov/research/umls/rxnorm/) using standard methods.The presence or absence of medications often used in Crohn's disease was used as a potential exposure for defining cases and non‐cases. Medications included3.4Six different Crohn's disease case algorithms were initially compared against a Crohn's disease registry at a single institution to begin to understand the interaction between sensitivity, specificity and number of times a diagnosis or medication was encountered in the chart (data not shown). From this we narrowed the potential algorithms down to four case and two non‐case algorithms, which used a combination of diagnoses and medications. Data from these four algorithms are the focus of the manuscript. All case algorithms required a Crohn's disease diagnosis recorded during a physician visit or specified as a problem list entry at least one or more times in the dataset, representing different encounters. Diagnoses captured during other, non‐face‐to‐face or non‐physician encounter types  were excluded to reduce the risk of inaccurate or unreliable diagnoses. Some of the test algorithms also included use of any Crohn's disease medications (at any point in time). Table Because the distinction between Crohn's disease and ulcerative colitis can be difficult to determine, and it is not uncommon for a patient to have both diagnoses recorded at some point in their chart,Non‐case test algorithms included patients with a gastrointestinal diagnosis other than Crohn's disease, ulcerative colitis, or indeterminate colitis seen at an in‐person encounter. One non‐case test algorithm included patients seen by any medical specialty  whereas the other  required having a visit specifically with a gastroenterologist or in a gastroenterology specialty care site Figure . Special3.5We conducted reliability testing across years to assess the stability of the computable phenotype by examining the proportion of cases that had at least one additional follow‐up visit for Crohn's in any subsequent year. To examine known‐group validity, patient age distributions and sex ratios were assessed to determine if any of the Crohn's disease algorithms generated cohorts with unexpected distributions of these variables.3.6At each PEDSnet institution, we conducted manual chart reviews of a random selection of 45 case patients using the final algorithm (3+ diagnosis codes plus 1+ medications) and 45 non‐case patients from the gastroenterology clinic population. The charts of an additional randomly selected 10 patients from each institution with an alternative case definition algorithm (1+ Crohn's disease diagnoses and 1+ medications) were also reviewed. Institutional chart reviewers received identical training and used an evaluation algorithm that systematically assessed different components of the electronic medical record  to determine whether the patient had a definitive diagnosis of Crohn's at the most recent gastroenterology visit . Chart review data were entered directly into a Research Electronic Data Capture (REDCap)4Figure 4.1As expected, with comparison to a Crohn's disease registry from one of the PEDSnet sites the least specific algorithm version led to highest sensitivity, and the most specific algorithm version led to the highest precision Figure . The fal4.2Table 4.3Sensitivity, specificity and positive predictive value for the primary case algorithm (3+ diagnosis codes plus 1+ medications), the alternative case algorithm (1+ diagnosis codes plus 1+ medication), and the non‐case algorithm (GI population) are shown in Table For discrepant cases identified using the 3+ diagnosis plus 1+ medication algorithm, two investigators conducted an error analysis to identify recurrent patterns. There was 100% agreement between the two investigators in the final disposition of the charts. There were two main reasons for these false positives (or type I errors): patients in whom an initial diagnosis of Crohn's disease was eventually reversed, and patients with indeterminate colitis or with suspected Crohn's that had not yet been biopsy confirmed. There were a small number of patients with other reasons for misclassification (n = 3) related to an initial concern for Crohn's that was eventually diagnosed as something else. No patients were identified where coding mistakes or “rule out” Crohn's disease resulted in the false positive result. Among those identified with the non‐case algorithm, the false negatives (or type II errors) included cases with insufficient follow‐up , and cases that represented early onset patients at the time of the data extract.5This study describes an overall process for developing computable phenotypes in PEDSnet, a large‐scale data network and Learning Health System, using Crohn's disease as a use case. Using a combination of informatics and clinical expertise and an internal validation and testing framework, we were able to confirm using records review that the process yielded a Crohn's disease computable phenotype with high sensitivity, specificity, and positive predictive value. We believe that this process can be generalized for other child health conditions within PEDSnet or other data sources that have similar data structures and definitions.Compared to more manual approaches, automated computable phenotypes are highly advantageous for developing study cohorts in terms of efficiency and cost. This is especially important for diseases or health conditions that are rare, where a large population of patients would need to be screened to obtain reasonable sample sizes for studies. Given the high performance of the Crohn's disease computable phenotype developed in this project, we believe that PEDSnet, which now contains robust health care data on over six million children across eight children's hospitals, is a unique and valuable resource for this type of work more broadly. Similarly, collaboratives such as the Observational Health Data Sciences and Informatics (OHDSI)In this study, we evaluated the computable phenotype for Crohn's disease in a population of children and adolescents specifically. This is notable because for some diseases differences in disease impact and treatment patterns often require different phenotypes to track disease activity in children than in adults.While the sex and age distributions for Crohn's disease are consistent with a previous cross‐sectional study conducted on pediatric claims data for 2004 to 2009, the overall prevalence of Crohn's disease reported here is much higher.For this study we developed a comprehensive SNOMED‐CT based diagnosis codeset, which allowed us to overcome discontinuities due to ICD version changes and low‐specificity codes, particularly in ICD‐9‐CM. We also utilized the multifaceted nature of EHR data,  to refine the phenotype. Adding a medication criteria to the algorithm further enhanced the algorithm's accuracy. While not done in this study, a previous study in adult Crohn's patients demonstrated that adding the presence of specific narrative phrases associated with Crohn's disease from clinical notes  improved the positive predictive value of the algorithm by 7% compared to an algorithm consisting of only ≥5 Crohn's ICD‐9 codes, and by 12% compared to an algorithm consisting of ≥1 outpatient Crohn's ICD‐9 code plus endoscopy.An important consideration for this study is that for this project we chose to develop a Crohn's disease computable phenotype that optimized sensitivity along with specificity. For some projects other prioritizations may be preferred and more or less exclusive categorizations may be needed. For example, if the goal is to directly contact patients for potential enrollment in a Crohn's medication trial, one might want to prioritize specificity so as not to erroneously convey to patients and their families that they have Crohn's disease when in fact they do not . On the other hand, if the goal is to screen children who have or are at risk for Crohn's for a longitudinal biomarker study, prioritizing sensitivity may be preferred . Adding to this balance is the fact that for rare diseases like Crohn's, the pretest probability of having this disease is low, so false negatives are relatively rare. The approach described in this manuscript should be considered a general framework for computable phenotyping that can be altered depending on researchers' study needs.This study should be considered in the context of several important limitations. First, while we describe an overall process for computable phenotype development, this particular study focused only on Crohn's disease. Further testing of the computable phenotype process as it is applied to other pediatric health conditions is needed to understand its generalizability for PEDSnet, as well as for other data sources. A second limitation is that, while one can reasonably calculate sensitivity and positive predictive values using the method and data source described, we reviewed only a subset of patient charts identified by our algorithms. It is nearly impossible to accurately define the frequency of false negatives in the entire population because of the possibility of incomplete data capture. A third limitation is that the use of broad fact ratios (here the presence of more Crohn's disease than ulcerative colitis diagnose), while producing simpler algorithms, may miss patients whose diagnoses converts from one to the other, whether through disease evolution or correction of miscoding.6We were able to successfully develop a computable phenotype for Crohn's disease from PEDSnet, a robust data source representing over six million children. Using a structured validation and evaluation process, we demonstrated that our EHR‐based algorithm for identifying Crohn's disease patients had a high sensitivity, specificity and positive predictive value. This computable phenotype will likely be of use for future studies to identify cohorts of pediatric Crohn's disease patients for retrospective observational analyses as well as prospective clinical trials. The overall approach we present can be applied to other pediatric disease states and conditions to advance child health research more broadly.Amanda Dempsey serves on Advisory Boards for Merck and Pfizer, and as a consultant to Pfizer for immunization‐related studies. She does not receive any research funding from these companies, and they played no role in this research. Michael Kappelman serves as a consultant to Johnson & Johnson, Abbvie, Pfizer, GlaxoSmithKline, and Lilly but these companies played no role in this research. All other authors have no conflicts of interest to declare.Figure S1 Performance of Crohn's Disease Computable Phenotype Algorithms Compared to a Manually Curated list of Crohn's Disease PatientsTable S1. Association of Crohn's Disease CP Algorithm Components with Select GI Clinical TestsTable S2. Crohn's disease codesetTable S3. Ulcerative colitis codesetTable S4. Indeterminate colitis codesetClick here for additional data file.


The effectiveness of school alcohol polices may be affected by the degree of strictness of rules, how they are implemented and enforced, students’ perception of the rules and the consequences of breaking them. The aim of the study was to test the hypothesis that more liberal school alcohol policies, lack of knowledge of the alcohol policy, lower prices of alcohol at school parties, and liberal party regulation were associated with more drinking among high school students.n = 68,898), participating in the Danish National Youth Study in 2014. Data came from questionnaires answered by high school students and school headmasters. Zero-inflated negative binominal regression with clustering of schools (n = 117) was used to assess the associations between alcohol policy reported by school headmaster and weekly alcohol intake reported by students. Multilevel negative binominal regression was used to assess the associations between alcohol price and liberal party regulations and units consumed at the last school party and units consumed at the school during the last school party.Participants were high school students (p = 0.000), compared to students who knew the policy. Lower beer prices were positively associated with the number of drinks consumed at the school (p = 0.004), but not with the total amount consumed at the last school party (p = 0.728). High school students who agreed that students who were drunk could buy alcohol had a higher alcohol intake at the last school party  and drank more at the school  compared to those who did not agree that students who were drunk could buy alcohol.In general, school alcohol policies were not associated with high school students’ weekly alcohol intake. High school students who did not know the school alcohol policy had a higher weekly alcohol intake (0.16 drinks 95% CL  School alcohol policies were generally not associated with drinking among high school students, whereas students’ lack of knowledge of the school policy was associated with a higher weekly alcohol intake. An addition, lower prices and liberal party regulation was associated with higher alcohol intake at school parties. Excessive alcohol use among young people is an international public health concern and developing effective ways of regulating alcohol use is a high priority. There is increasing recognition that alcohol use among young people is influenced by both individual and contextual factors such as social norms and availability and price of alcohol. At the national level, more comprehensive alcohol control policies that regulate the availability and prices of alcohol have been associated with reduced frequency of alcohol use among young people –4. FurthHigh school students spend most of their daytime at school and the school is one of the most influential socialization domains in young people’s lives. While the primary objective of a school is to educate, it also constitutes a social context where students interact with teachers and other students and share norms and values that may implicitly or explicitly, confer varying levels of approval toward alcohol use, affecting the behaviour of students –7. AlcohDanish adolescents have one of the highest prevalence of drunkenness among adolescents in Europe . Among DIn this study we use data from multiple data sources to obtain a comprehensive picture of alcohol policies at Danish high schools. We want to analyse the association between alcohol policies and alcohol use among students, as well as the association between students’ knowledge of the policy, alcohol prices at school parties and liberal regulation at school parties, and alcohol intake among students at school parties. We hypothesize that more liberal school alcohol policies, students’ lack of knowledge of the policy, lower prices and liberal regulation at school parties are associated with higher alcohol intake among students.The data came from the Danish National Youth Study 2014, a national survey of 75,858 high school and vocational school students. The Danish National Youth Study was conducted with the aim of investigating health, health behaviour and mental health among secondary education students in Denmark. All of Denmark’s 137 general high schools and the 12 largest vocational schools were invited to participate. Only high schools were included in this study. The school participant proportion was 87% and the individual participant proportion was 84% in high schools. Teachers gave students a code to access the electronic questionnaire and students answered the questionnaire in class during one to two lessons lasting 45 min each.In addition to the student questionnaire school headmasters were also invited to complete a questionnaire on school strategies for improving health and well-being, and the rules and general practice of schools when dealing with smoking and alcohol use among students. Of the 119 high school headmasters, 117 answered the school headmaster questionnaire. A thorough description of the study is reported elsewhere .n = 61) were randomly selected to participate in this more detailed alcohol study. In order to obtain data on party regulation and alcohol prices three to five students at each high school were asked to complete a short mobile questionnaire at the party (Friday) and after the party (Monday)  and those with missing data on weekly alcohol intake (n = 851) were deleted from the analyses leaving a total study population of 68,898 for further analyses.Information from the school headmaster questionnaire and student mobile questionnaire were merged on to the student questionnaire based on school. See Table Alcohol use was characterised by three measures.Weekly alcohol intake: participants were asked how many alcoholic drinks  they typically drink on each day of the week. A total weekly alcohol intake variable was calculated summing the daily intake.Units consumed during the last school party: participants who had been to a school party were asked how many alcoholic drinks they consumed at the last school party (including drinking at pre-parties and after-parties) . For each category the mid-point value was taken. Students who had never attended a school party were excluded (n = 4677), leaving n = 63,820 for analysis.Units consumed at school during the last school party: participants were asked how many of these drinks they consumed at the school during the last school party (excluding drinking at pre-parties and after-parties outside the school). Those who did not drink during the last school party and those who had never attended a school party were excluded, leaving n = 58,308 for analysis.School headmasters were asked ‘Has the school adopted an alcohol policy?’ (Yes/No) and whether ‘The alcohol policy is communicated to new students?’, if ‘It is checked if students comply with the alcohol policy’, and ‘Does it have consequences if students do not comply with the alcohol policy?’. The answers were coded ‘Yes’ for “Always/almost always” and “Often”, and ‘Not consistently’ for “Sometimes” and “Never or almost never”. School headmaster reported whether students were allowed to drink at introduction trips, study trips, educational events outside school hours, social events Monday to Thursday, and social events Fridays and Saturdays. Answers were dichotomised into ‘Yes’  and ‘No’ (“No” and “Do not arrange”). School headmasters were asked to indicate who was served alcohol at school events with the possible answers “Everyone”, “Everyone older than 16 years”, “everyone older than 18 years”, and “specific classes”.Students’ knowledge of the alcohol policy was measured in the student questionnaire by the question ‘Does your school have an alcohol policy?’ with the possible answers ‘Yes’, ‘No’ and ‘Don’t know’.Alcohol price was based on self-reported data on beer and alcopops from students who participated in the school party. At each school, between three and five students were asked to answer a short mobile questionnaire at the party and after the party. The questionnaire included questions about alcohol regulation at school parties, prices in the bar and whether there were adults in the bar. Prices on wine and spirits were excluded from the analyses due to missing data (e.g. few schools sold spirits). Students were asked to take photos of the bar menu and send it to the researchers. The pictures were used to validate students’ answers where there was discrepancy in students’ answers in the questionnaire.Bar staff/adults in the bar: as well as bar prices the students were asked to specify who sold alcohol at the bar.Party regulation was also measured by two items included in the student questionnaire. Participants were asked how much they agreed with the following: ‘Students are sent home if they are very drunk’, and ‘Students who are drunk can buy alcohol ’. Responses were dichotomized into ‘Agree’  and ‘Do not agree’ . “Neither disagree nor agree” was coded conservatively to ‘Disagree’.n = 117) was used to assess the associations between alcohol policy reported by school headmasters and weekly alcohol intake among students, as well as the associations between students’ knowledge of the alcohol policy and students’ weekly alcohol intake. Weekly alcohol intake was non-normally distributed with excessive zeros. The Vuong test showed that a zero inflated negative binominal model was preferred to a standard negative binominal regression model (p < 0.001). Multilevel negative binominal regression was used to assess the associations between alcohol price and students’ perceptions of party regulation and units consumed at the last school party and units consumed at the school during last school party. A two-level random intercept model was applied with students (level 1) nested within schools (level 2). All analyses were adjusted for age (continuous) and gender (boys/girls) and performed in STATA 15.We analysed data using multilevel modelling, thereby taking into account the hierarchical data structure. We had three outcomes: 1) weekly alcohol intake 2) units of alcohol consumed during last school party and 3) units consumed at school during the last school party. Zero-inflated negative binominal regression with clustering of schools , 29% lived with one parent and 6% lived alone (Table p = 0.025), compared to students in schools where the school headmaster reported that alcohol was not sold at social events at the weekend (5%). Some school headmasters reported that there were restrictions on who could buy alcohol at school events (26%). However, setting restrictions in terms of age limits on who could buy alcohol was not associated with students’ weekly alcohol intake.A total of 97% of school headmasters reported that they had adopted an alcohol policy Table . Not adop = 0.000). Not knowing whether the school had an alcohol policy was not associated with a higher weekly alcohol intake, compared to students who knew their school had an alcohol policy.Most students 64%) answered that their school had an alcohol policy, while 4,3% disagreed and 31% did not know whether their school had an alcohol policy (Table % answerep = 0.004) compared to students in schools with higher beer prices (25 DKK or more). The same tendency with higher alcohol intake at school were also seen with higher alcopop prices, however the test for trend was not significant (p = 0.071). Having adults in the bar or offering more types of alcoholic drinks were not associated with units consumed at last school party (data not shown).Lower prices for beer and alcopops were not associated with a higher total alcohol intake at school parties  Table . Howeverp < 0.001) compared to those who agreed that students are sent home if they were very drunk (Table p < 0.001) and drank more at the school  compared to those who did not agree that students who are drunk can buy alcohol.Students who did not agree that students are sent home if they are very drunk (50%) had a higher alcohol intake at the last school party  does not apply for private events. Most high schools allow alcohol at social events during the weekend (95%) and generally do not have strict rules on alcohol use. Allowing alcohol at social events at the school on Fridays and Saturdays was associated with higher weekly alcohol intake among students, compared to schools that did not allow alcohol at social events during the weekend. In line with this result, research among slightly older young people in the US showed that students attending colleges that ban alcohol were less likely to binge drink and more likely to abstain from alcohol  years do. HoweverIn line with our findings, the price of alcohol has previously been found to be an important factor in drinking among college students. Low prices and easy access to alcohol has been found to be strongly correlated to binge drinking among college students . Lower bLiberal party regulation was associated with a higher alcohol intake at school parties. Students who disagreed that students are sent home if they are very drunk were associated with higher total alcohol intake at the last school party, but not higher alcohol intake at the school. Students who agreed that students who are drunk can buy alcohol had a higher alcohol intake at the last school party, both in total and at the school. The result could possibly be due to reversed causation as only students who drink more at parties know whether they are sent home or can buy alcohol when they are drunk. This could also indicate that students’ perception of enforcement of the alcohol policy and the accessibility of alcohol might be crucial and may be more important than formal rules. University of Washington professor of Social Work Richard Catalano and colleagues  studied n = 117) and students , which reduced the risk of random errors.One of the major strength of this study is that data came from several different sources. By including data on school policy from school headmasters, student observation at school parties and questionnaire data on drinking among students, we were able to give a comprehensive and detailed picture of how different school policies affect students’ drinking. In addition, this study included a large number of schools . Party observation questionnaire.


This study aimed to compare outcomes of percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) in the elderly (≥75 years) versus nonelderly and assess the impact of successful CTO‐PCI in the elderly.PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched up to October 1, 2020. Mortality rates and major adverse cardiac events (MACE) were compared between elderly and nonelderly patients and successful versus failed CTO‐PCI in the elderly.2 = 0% p = .15) but higher tendency of in‐hospital MACE  in the elderly group. Risk of long‐term mortality  and long‐term MACE  were significantly increased in the elderly versus nonelderly. Elderly patients had a significantly reduced odds of successful PCI as compared to nonelderly patients . Successful CTO‐PCI was associated with reduction in long‐term mortality  and MACE  as compared to failed PCI in elderly.Eight studies were included. Meta‐analysis indicated no statistically significant difference in the risk of in‐hospital mortality (RR: 1.97 95% CI: 0.78, 4.96 IElderly patients may have a tendency of higher in‐hospital MACE with significantly increased long‐term mortality and MACE after CTO‐PCI. The success of PCI is significantly lower in the elderly. In elderly patients with successful PCI, the risk of long‐term mortality and MACE is significantly reduced. The cohort of the elderly population is increasing with a corresponding increase in the prevalence of the cardiac disease, especially coronary artery disease (CAD).Historical data indicates that coronary artery bypass graft (CABG) surgery or medical therapy were commonly used strategies for CTO.Despite evidence suggesting favorable outcomes with PCI for CTO, the procedure is infrequently performed in the elderly population. The reluctance stems from the fact that the disease is more complex in older patients and evidence from non‐CTO PCI studies indicating higher complications and mortality in the elderly.22.1The review is conducted as per the guidelines of the PRISMA statement .1. Studies were to compare outcomes of elderly patients with nonelderly patients (<75 years of age). Outcomes reported were to be mortality and/or major adverse cardiac events (MACE).OR2. Studies were to compare outcomes of successful and failed PCI for CTO in elderly patients. Outcomes of interest were mortality and/or MACE.No restriction was placed on the study design, sample size, language of publication, or date of publication. The following were the exclusion criteria for the review: 1. Studies comparing outcomes of PCI versus medical therapy only. 2. Studies comparing outcomes of PCI versus CABG only. 3. Studies not segregating data based on elderly and nonelderly subjects. 3. Studies using any other definition of the elderly population . 4. Studies not reporting relevant data. 5. Review articles and unpublished studies were also excluded.2.2An electronic search was conducted by two reviewers, independent of each other, for the following databases: PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar. The time limit was from the inception of databases to October 1, 2020. The terms used for the literature search included: “percutaneous coronary intervention,” “chronic total occlusion,” “elderly,” “older adults,” “geriatric,” and “age.” Search terms were used in different combinations to find relevant articles. After the deduplication of articles, the search records were analyzed by their titles and abstracts separately by the two reviewers. Articles matching the inclusion criteria were identified and full texts of these were extracted. Individual studies were then assessed for final inclusion in the study. Any disagreements were resolved by discussion. After completion of the search and identification of included studies, the bibliography of included articles was hand searched for any other potential article.2.3The following data were extracted from the included studies: names of first authors, publication year, study type and location, study groups, sample size, demographic details of the sample, medical history of the sample , the success of PCI, CTO location, contrast volume use, procedural time, study outcomes, and follow‐up time.For the first part of the review, mortality and MACE were compared following CTO‐PCI in elderly versus nonelderly. We also performed a separate analysis comparing major bleeding, cardiac tamponade, emergent CABG, MI, and cerebrovascular accident (CVA) between the elderly and nonelderly groups. Finally, the success rates of PCI were compared between the elderly and nonelderly groups. For the second part of the review, we compared mortality and MACE between successful PCI versus failed PCI for CTO in the elderly.Since only observational studies were included in the review, the risk of a bias assessment tool for nonrandomized studies (RoBANS) was used to assess the quality of included studies.2.42 statistic. I2 values of 25–50% represented low, values of 50–75% medium, and more than 75% represented substantial heterogeneity. As less than 10 studies were included in the meta‐analysis, funnel plots were not used to assess publication bias.“Review Manager”  was used for the meta‐analysis. Using a random‐effects model, all categorical adverse outcomes were summarized using risk ratios (RR) with 95% confidence intervals (CI). The success of PCI between elderly and nonelderly was compared using odds ratios (OR). We also extracted data on hazard ratio (HR) for mortality or MACE if reported by the included studies. The generic inverse variance model of the meta‐analysis software was used to pool the HR. Meta‐analysis was conducted only if at least three studies reported the same outcome. Heterogeneity was assessed using the I3The PRISMA flowchart of the review is presented in Figure 3.12 = 0% p = .15)        and long‐term outcomes were compared separately for this part of the analysis. A meta‐analysis of data from 4977 patients indicated no statistically significant difference in the risk of mortality between elderly and nonelderly patients undergoing CTO‐PCI  Figure . Pooled ) Figure . On furt2 = 41% p < .00001)  and cardiac mortality . A meta‐analysis of four studies reporting data on long‐term MACE indicated a significantly increased risk of MACE in the elderly undergoing CTO‐PCI    Figure . Results) Figure . On comp3.22 = 39% p = .32)  as well as for cardiac mortality . On the other hand, pooled analysis of four studies indicated significantly reduced risk of long‐term MACE in patients with successful PCI as compared to failed PCI     In‐hospital mortality for CTO‐PCI may not be different between elderly and nonelderly, but there is a tendency of higher risk of early MACE in the elderly group. (2) Risk of long‐term mortality and MACE is significantly increased in the elderly following CTO‐PCI. (3) Success of PCI is significantly lower in the elderly versus nonelderly. 4) In elderly patients with successful PCI, the risk of long‐term mortality and MACE is significantly reduced as compared to those with failed CTO‐PCI.CTO is common in the elderly population and accounts for poor clinical outcomes in this age group. Therefore, the European Society of Cardiology (ESC) and the European Association for Cardio‐Thoracic Surgery (EACTS) recommend that myocardial revascularization in the presence of CTO be considered if there are symptoms or objective evidence of cardiac ischemia in the area of the occluded artery.In this context, an important question that needs to be answered is if CTO‐PCI has similar outcomes in elderly and nonelderly subjects? The concern of poor outcomes in the elderly with CTO arises from the fact that the disease is more extensive in older adults and coronary arteries are more tortuous with heavy calcification of atherosclerotic plaques.The success of PCI for CTO in the literature ranges widely from 59 to 87.5%.Our review has some limitations. Foremost, our meta‐analysis included only observational studies and not randomized controlled trials. Selection bias may have skewed outcomes of the individual studies and thus influencing the results of this meta‐analysis. Second, there were significant baseline differences in the elderly and nonelderly groups. There was no reporting of multivariable‐adjusted HR for comparing outcomes of elderly and nonelderly groups. Several of these baseline variables could have generated bias in the results. Third, outcomes of CTO‐PCI also depend on the experience and skill of the operator. The influence of this variable could not be judged on the study results. Last, the number of patients in the elderly group in some studies was not high (<100 patients). This compounded by the limited number of studies available for each meta‐analysis may have reduced the statistical power of the review.5To conclude, our study indicates that elderly patients may have a tendency of higher in‐hospital MACE with significantly increased long‐term mortality and long‐term MACE after CTO‐PCI.The success of PCI is significantly lower in the elderly versus nonelderly patients. In elderly patients with successful PCI, the risk of long‐term mortality and MACE is significantly reduced as compared to those with failed CTO‐PCI. Further larger studies using multivariable‐adjusted models are needed to strengthen the evidence.The authors declare that they have no competing interests.Chenmin Cui conceived and designed the study. Chenmin Cui and Zhichao Sheng collected the data and performed the literature search. Chenmin Cui was involved in the writing of the manuscript. All authors have read and approved the final manuscript.FIGURE S1 Forest plot of in‐hospital major bleeding after CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S2 Forest plot of emergent CABG after CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S3 Forest plot of in‐hospital MI after CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S4 Forest plot of in‐hospital cardiac tamponade after CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S5 Forest plot of in‐hospital CVA after CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S6 Forest plot of success of CTO‐PCI in elderly versus nonelderlyClick here for additional data file.FIGURE S7 Forest plot of long‐term mortality after successful versus failed CTO‐PCI in elderlyClick here for additional data file.FIGURE S8 Forest plot of long‐term MACE after successful versus failed CTO‐PCI in elderlyClick here for additional data file.FIGURE S9 Forest plot of hazard ratios of long‐term mortality after successful versus failed CTO‐PCI in elderlyClick here for additional data file.FIGURE S10 Forest plot of hazard ratios of long‐term MACE after successful versus failed CTO‐PCI in elderlyClick here for additional data file.TABLE S1 Risk of bias in included studiesClick here for additional data file.


Due to the complexity of the inflammation process and its role in common diseases like asthma, cancer, skin disorders or Alzheimer's disease, anti‐inflammatory drugs are of high pharmaceutical interest. Nature is a rich source for compounds with anti‐inflammatory properties. Several studies have focused on the structural optimization of natural products to improve their pharmacological properties. As derivatization through total synthesis is often laborious with low yields and limited stereoselectivity, the use of biosynthetic, enzyme‐driven reactions is an attractive alternative for synthesizing and modifying complex bioactive molecules. In this minireview, we present an outline of the biotechnological methods used to derivatize anti‐inflammatory natural products, including precursor‐directed biosynthesis, mutasynthesis, combinatorial biosynthesis, as well as whole‐cell and  Nature's wealth of bioactive molecules. This minireview gives an overview of biotechnological methods that can be used for the derivatization of natural anti‐inflammatory agents. It covers established techniques such as whole‐cell biotransformation and precursor‐directed biosynthesis, as well as recently developed concepts that involve enzyme engineering. Selected examples illustrate the diversity of structural modifications that are now possible through bioengineering. It was though not until the end of the 18th century that scientists isolated and characterized the active compounds therein. The initially isolated salicin was described as the sugar conjugate of salicylic acid, and the latter soon found its way into treatment of fever and inflammatory rheumatoid arthritis.Inflammation is initiated by a multitude of external and internal triggers and it can lead to acute or chronic diseases with characteristic symptoms including pain, fever, reddening, swelling and impaired functionality.Inflammatory processes include complex physiological pathways, that also interconnect with many other signaling cascades, affecting cancer development, blood coagulation as well as immune and allergic reactions.Natural products played essential roles in the identification of inflammatory pathways. An illustrative example is given by the bacterial macrolides sirolimus (rapamycin) and tacrolimus (FK506). Following the discovery that both natural products bind the FK‐binding protein 12 (FKBP‐12), the respective downstream mechanism through the phosphatase calcineurin and the kinase target of rapamycin (TOR) could be clarified.21; Figure Natural products are often regarded as evolutionarily optimized ligands for biological targets and receptors.11, 12in vitro conditions.Although semisynthetic approaches are of high relevance, they are occasionally hampered by positional selectivity and the reactivity of interfering functional groups. A smart way to circumvent these issues is the use of biotechnological methods, which allow the derivatization of natural products in a regio‐ and stereocontrolled manner. The available techniques can be roughly divided into those, which make use of living cells to biosynthesize unnatural analogues and those, in which the modifications are carried out with purified enzymes under 2.1A well‐known method to increase the structural diversity from an isolated natural product is whole‐cell biotransformation. The molecule of interest is fed to an organism other than the producer (in most cases a fungus or a bacterium), which then carries out various site‐specific and stereospecific reactions Figure A.18, 18, 19Another easy way to obtain natural product derivatives is to supply the producer organism with analogues of biosynthetic building blocks, such as halogenated amino acids or aryl carboxylic acids. Depending on cellular uptake and the substrate tolerance of the biosynthesis enzymes, these analogues can compete with and replace the metabolically derived precursors Figure B.[22] The aforementioned issues can be circumvented with a technique called mutasynthesis. This technique presupposes the elimination of a biosynthetic precursor or intermediate by targeted gene inactivation. The resulting mutant is no longer capable to make the corresponding natural product unless the missing building block is added to complement the biosynthesis. If the mutant is instead exposed to a non‐natural surrogate of the precursor, this so‐called “mutasynthon” will be recruited for the biosynthesis and form a natural product analogue without an accompanying parental molecule Figure C.14, 14, 23Both PDB and mutasynthesis exploit the inherent promiscuity of biosynthetic enzymes. In general, the substrate flexibility of these catalysts confines the range of possible derivatizations, but this boundary can be overcome through genetic engineering. An increasing number of studies make use of biosynthesis enzymes that were mutagenized in order to expand or to alter their substrate specificity Figure D.24, 24, 27We refer to the corresponding studies as mutaXchange, even though the term enzyme‐directed mutasynthesis is also used in the literature.2.2in vitro biotransformation is analogous to whole‐cell biotransformation, it offers several advantages over the latter. As applied biocatalysts are known, they can be used in a much more directed and predictable way. Transport limitations due to poor cellular uptake of the natural product substrate are avoided and the purification of the conversion products becomes easier, as no metabolic by‐products need to be separated. It should be noted that in vitro biocatalysis has become quite popular in pharmaceutical industry for the design of greener, sustainable manufacturing processes. This development is also not restricted to natural product‐derived drugs, as illustrated by the enzymatic synthesis of the antihyperglycemic agent sitagliptin.The structural diversification of natural products can also be carried out with purified enzymes in a biocatalytic approach Figure F. Althou3In the following section, we shall highlight anti‐inflammatory natural products that have been bioengineered to improve their properties (Table S1). This compilation is far from comprehensive and it is also not intended to be so. The examples were chosen to illustrate the different methods introduced in Section 2 and will mainly cover studies that have been reported since 2010.3.12) is among the clinically most relevant immunosuppressant compounds.Tacrolimus ‐4,5‐dihydroxycyclohex‐1‐enecarboxylic acid (DHCHC)l‐pipecolate unit is attached by an NRPS. A subsequent cyclization generates the macrolide scaffold of 2, which is then subjected to further oxidation and methylation reactions.[The bacterial natural product is assembled by a polyketide synthase (PKS)‐nonribosomal peptide synthetase (NRPS) enzyme complex.44, 452 was extensively modified both chemically and biotechnologically to create analogues with improved stability, solubility and reduced toxicity. Structure‐activity relationship (SAR) studies indicated two sites on this natural product to be of primary interest for derivatizations. Thus, modifications at the cyclohexyl moiety do not affect the inhibition of calcineurin, but influence stability and solubility, whereas modifications in the allyl side chain directly correlate with the immunosuppressive bioactivity.[The molecular structure of activity.50, 51To alter the cyclohexyl moiety through bioengineering, the DHCHC pathway needs to be inactivated in the tacrolimus‐producing bacterium. Feeding of the mutant with cyclic carboxylic acids fuels the biosynthesis and leads to the mutasynthetic production of various derivatives Figure .[50, 2 is biosynthetically accessible via the enzyme TcsB, an unusual β‐ketoacyl synthase. Thus, after disruption of the tcsB gene, unnatural extender units similar to allylmalonyl‐CoA can be channeled into tacrolimus biosynthesis. One noteworthy compound that was produced in this way is 36‐methyl‐tacrolimus.tcsB mutant.The allyl side chain of 3.23) is the prototype of a family of red‐colored pigments featuring a tripyrrole ring structure.3 and its analogues are less known. Various studies showed that the prodiginines delay the progression of arthritis and improve gastric inflammations by interference with inflammatory mediators, such as the IL‐2 receptor α‐chain, NFκB, nitric oxide (NO), iNOS or JNK.[In silico studies further suggest that the prodiginines act as COX‐2 inhibitors.Prodigiosin .in vitro.In 2018, the production of prodiginines by whole‐cell biotransformation was reported. In this study, the key biosynthesis enzyme PigC from 3.34) are bacterial siderophoresThe myxochelins  in 1817 and is, after morphine, the alkaloid with the second highest abundance in opium.[5 gained increasing attention as a chemotherapeutic agent due to its potent tubulin‐binding properties and its good safety profile.5 and some semisynthetic derivatives were reported to possess anti‐inflammatory activity. The tested noscapinoids were shown to inhibit the TLR‐induced release of TNF‐α, IL‐8 and NO without affecting cell viability.5 were found to be significantly more potent than the natural product, thus demonstrating the importance of derivatization.The benzylisoquinoline alkaloid noscapine  and involves a number of biocatalytic steps via the intermediates norcoclaurine, reticuline (7), scoulerine, canadine and secoberbine. In 2016, the Smolke group achieved the production of 5 in a microorganism for the first time. After reconstitution of 16 biosynthetic enzymes in the yeast Saccharomyces cerevisiae, the alkaloid could be produced from the precursors canadine and norlaudonosoline.5de novo from a simple carbon source.The biotechnological production of noscapine analogues became possible following the discovery and characterization of its biosynthesis gene cluster in the opium poppy.104 The 7, a key intermediate in noscapine biosynthesis, with a titer of 4.6 g/L.5, which then enabled the production of N‐demethylated and different hydroxylated noscapine derivatives under in vitro conditions.Recently, metabolic engineering of yeast allowed the production of 3.5Among higher terrestrial plants, the saponins are widely distributed as defense compounds against herbivores and pathogens.Panax ginseng named ginsenosides. Rare ginsenosides can be obtained by enzymatic deglycosylation and hydrolysis. These conversions are typically carried out with microorganisms, such as lactic acid bacteria or fungi as Aspergillus niger.[8) was approved by the China Food and Drug Administration for treatment and prevention of arthritis.8 is produced by deglycosylation of protopanaxadiol‐type ginsenosides  should be addressed to the authors.SupplementaryClick here for additional data file.


The abscopal effect was first described in 1953 by Dr Mole as “an effect of ionizing radiation at a distance from the irradiated volume but within the same organism,” and it now refers to shrinkage of non‐irradiated primary and/or metastatic lesions following radiotherapy.IJU Case Reports, Ishiyama et al. reported the case of a patient with renal pelvic cancer who had recurrence after radical nephroureterectomy.In this issue of et al. investigated the characteristics of the abscopal effect among the 126 patients who received an immune checkpoint inhibitor and radiation therapy. Twenty‐four of these patients had eligible non‐irradiated lesions and an abscopal effect was observed in seven patients .Based on the promising anti‐tumor efficacy and a manageable safety profile, pembrolizumab therapy has been rapidly introduced and the paradigm of medical treatment for metastatic urothelial cancer is dramatically changing in clinical practice in Japan.The author declares no conflict of interest.


A key implication of the cancer stem cell model is that for a cancer therapy to be curative, it is imperative to eliminate the cancer stem cells (CSCs) that drive tumor progression. The California Institute for Regenerative Medicine is supporting two novel approaches that target CSCs, one an antibody‐mediated immunotherapy targeting CD47 and the other an antibody targeting ROR1. This article summarizes the evidence that CSCs are targeted and discusses the results of early clinical trials within the context of the CSC model. The Cancer Stem Cell (CSC) model asserts that tumors contain a subpopulation of CSC that drive tumor progression, positing that standard therapies are rarely curative because they spare the CSC, resulting in relapse after remission. Therapies that target primarily CSC are predicted to result in stable disease (SD) when used alone but are anticipated to induce durable responses when combined with standard therapies. The premise and predictions of the cancer stem cell model of cancer are being tested in the clinic as cancer stem cell‐targeted therapies enter clinical trials. This article describes two such approaches and discusses whether the initial clinical results are consistent with predictions of the model. Validation of the cancer stem cell model in humans has implications for the design of curative treatments for many human cancers.1The California Institute for Regenerative Medicine (CIRM), California's stem cell funding agency, selects highly meritorious projects using a rigorous peer review process and then partners with grantees to develop novel stem cell‐based treatments, including therapies aimed at eradicating cancer stem cells (CSCs). This article highlights two such approaches that are now in clinical trials.2The CSC model asserts that tumors are comprised of heterogeneous hierarchies of cancer cells, not all of which are capable of sustaining tumor growth or initiating new tumors. Rather, there exists within most tumors a unique subset of cells, termed CSCs, that have stem cell‐like properties such as relative quiescence as well as ability to self‐renew and differentiate. It is these cells that drive both tumor progression and metastasis.Evidence for the existence of CSCs was first provided in acute myelogenous leukemia (AML)Phenotypic as well as functional overlap between normal tissue stem cells and CSCs has been described in a number of cancers. AML LSC exhibit cell surface marker expression patterns characteristic of normal hematopoietic stem or progenitor cells.The CSC model can explain why most cancers recur after remissions induced by standard anticancer therapies. Stem cell‐like characteristics, such as relative quiescence as well as elevated levels of multidrug resistance transporters and DNA damage repair enzymes, enable CSCs to withstand chemotherapy or radiation and subsequently repopulate tumors and drive relapse.In the case of targeted therapies, expression of the target on more differentiated progeny cells within the tumor but not on CSCs would also spare CSCs and allow for relapse.A clear corollary of the CSC model is that a cancer therapy will never be curative unless the CSC population is eliminated. Many efforts are therefore underway to develop CSC‐targeted approaches.3CD47 is expressed widely on both cancer and normal cells throughout the body.This strategy has been extended to other cancers. Overexpression of CD47 is correlated with poor prognosis in non‐Hodgkin's lymphoma (NHL), ovarian cancer, gastric cancer, and lung cancer. In xenograft models of multiple patient‐derived solid tumors, treatment with an anti‐CD47 antibody inhibited tumor growth and prevented metastasis, consistent with an effect on CSCs.4CD47 functions as a ligand for signal regulatory protein‐α (SIRPα) on phagocytic macrophages, transmitting a “don't eat me” signal that inhibits phagocytosis.5The anticancer effects of the anti‐CD47 antibody in mouse models were synergistically enhanced by combining with another anticancer drug such as rituximab in a NHL modelRituximab is an anti‐CD20 monoclonal antibody that binds to normal and malignant B cells and is used to treat B‐cell lymphomas such as NHL. It is believed to act via its Fc effector functions, in part by engaging Fc receptors on NK cells and inducing antibody‐dependent cellular cytotoxicity. Macrophages also express Fc receptors and are postulated to contribute to the efficacy via antibody‐dependent cellular phagocytosis triggered by opsonization of target cells and engagement of macrophage Fc receptors by the rituximab Fc‐domain.Azacytidine is an anticancer chemotherapeutic indicated for the treatment of AML and myelodysplastic syndromes (MDS). Its mechanisms of action include inhibition of DNA methylation and cytotoxicity due to incorporation into DNA and RNA.6A humanized anti‐CD47 antibody  has been tested in early clinical trials. Despite widespread expression of CD47 on normal cells, CD47 blockade selectively targets cancer cells and not normal cells (except for aging red blood cells), presumably because cancer cells express prophagocytic signals that are absent from normal cells.The efficacy outcomes of four phase 1 trials in AML, NHL, and solid tumors, using magrolimab either as monotherapy or in combination with rituximab or azacytidine, are summarized in Table The ORR was significantly greater when magrolimab was combined with another cancer drug as predicted by preclinical experiments, either azacytidine in AML and MDS patients or rituximab in NHL patients, over and above expected outcomes from treatment with azacytidine or rituximab alone Table . In the In the phase 1b NHL trial in which magrolimab was combined with rituximab, 95% of patients had rituximab‐refractory disease, making it unlikely that the observed response rates (50% OR with 36% CR) were due to rituximab alone and suggesting that addition of magrolimab can overcome rituximab resistance.Viewed from the perspective of the CSC model, patients in this study, having relapsed after a median of four previous therapies, likely had tumors that were enriched for LSC. While the underlying mechanisms of resistance to rituximab are not well understood,7ROR1 is an embryonic tyrosine kinase‐like orphan receptor expressed on chronic lymphocytic leukemia (CLL) cells but not on normal B cells or most other adult cells.8ROR1 is a receptor for Wnt5a and ROR1‐dependent Wnt5a signaling has been implicated in CSC maintenance and self‐renewal and also in metastasis.A humanized anti‐ROR1 antibody (cirmtuzumab) was developed that inhibits ROR1‐dependent Wnt5a signaling by binding with high affinity to an epitope in the extracellular domain of ROR1.Cirmtuzumab blocked Wnt5a‐enhanced proliferation of CLL cells and inhibited leukemic engraftment in a mouse model.9Efficacy outcomes from two clinical trials using cirmtuzumab are summarized in Table Ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor that blocks B‐cell receptor signaling, is an effective therapy for patients with CLL although it does not completely eradicate disease.These preclinical experiments provided a rationale for combining cirmtuzumab with ibrutinib clinically and a phase 1/2 trial is currently testing the combination in CLL patients. Interim data from the first 12 patients in the phase 1 portion of the trial showed an overall objective response rate of 91.7% with a CR rate of 25% after 24 to 48 weeks of treatment10While acknowledging the extreme heterogeneity and complexity of human tumors, a simplified interpretation of the CSC model predicts the following: Therapies that target bulk tumor but not the CSC subpopulation may cause tumor shrinkage, inducing objective responses and even complete responses, but the responses will not be durable. In contrast, a therapy that targets primarily the CSC subpopulation but not bulk tumor cells might arrest tumor progression without inducing tumor shrinkage, resulting in SD without objective responses. A key prediction of the CSC model is that durable objective/complete responses will only be achieved by combined targeting of both bulk tumor cells and the CSC subpopulation.The two CSC‐targeted therapeutic strategies described above work by completely different mechanisms. Yet it is interesting to note a number of parallels. First, in both cases, high‐level expression of the target in human tumors is a negative prognostic marker, predicting shorter OS. Second, clinical evaluation of these strategies as monotherapy resulted primarily in SD, a result consistent with the predictions of the CSC model. Third, there is strong preclinical rationale for combination therapy with other anticancer drugs and although it is still too early to tell what the clinical combination trials will show, initial results appear promising and are consistent with additive or synergistic effects. Importantly, both approaches are well tolerated in humans and there appear to be no limiting toxicities.While overall response rate (ORR) is an accepted endpoint for evaluating efficacy of anticancer therapies, it does not test the basic premise of the CSC model. More meaningful endpoints will be duration of response, progression‐free survival, relapse‐free survival, and ultimately, OS. It remains to be seen whether the approaches described in this article will lead to long‐term, durable responses when combined with another anticancer therapy, as predicted by the CSC model.The author declared no potential conflicts of interest.


The quest for the effective treatment against coronavirus disease 2019 pneumonia caused by the severe acute respiratory syndrome (SARS)‐coronavirus 2(CoV‐2) coronavirus is hampered by the lack of knowledge concerning the basic cell biology of the infection. Given that most viruses use endocytosis to enter the host cell, mechanistic investigation of SARS‐CoV‐2 infection needs to consider the diversity of endocytic pathways available for SARS‐CoV‐2 entry in the human lung epithelium. Taking advantage of the well‐established methodology of membrane trafficking studies, this research direction allows for the rapid characterisation of the key cell biological mechanism(s) responsible for SARS‐CoV‐2 infection. Furthermore, 11 clinically approved generic drugs are identified as potential candidates for repurposing as blockers of several potential routes for SARS‐CoV‐2 endocytosis. More broadly, the paradigm of targeting a fundamental aspect of human cell biology to protect against infection may be advantageous in the context of future pandemic outbreaks. A key step in COVID‐19 pathogenesis is the entry of the SARS‐CoV‐2 virus into the airway epithelial cells; this process employs the cellular mechanisms of endocytosis, and therefore targeting these mechanisms has therapeutic potential for treating COVID‐19. Generic drugs that have been shown to inhibit endocytosis represent promising candidates for development of affordable anti‐COVID‐19 treatments. COVID‐19coronavirus disease 2019SARSsevere acute respiratory syndromeCoV‐2coronavirus 2CoVcoronavirusMERSMiddle East respiratory syndromeACE2angiotensin‐converting enzyme 2CtBPC‐terminal binding proteinAP2adaptor protein 2AP180adaptor protein 180Arfadenosine diphosphate‐ribosylation factorRac1Ras‐related C3 botulinum toxin substrate 1Cdc42cell division control protein 42https://www.worldometers.info/coronavirus/). This current epidemiological, economical and potentially political disaster in the making follows in the wake of earlier outbreaks of respiratory infections SARS and Middle East respiratory syndrome (MERS), also caused by coronaviruses [At the time of writing this piece, the pandemic of the atypical pneumonia coronavirus disease 2019 (COVID‐19) caused by a novel coronavirus severe acute respiratory syndrome (SARS)‐coronavirus 2 (CoV‐2) has spread globally, with more than 4 million cases and close to 300 000 deaths . Nasal epithelial cells abundantly express a wide variety of endocytic markers, suggesting the presence of multiple active pathways, in agreement with ultrastructural evidence [To establish which endocytic pathways are likely to operate in nasal epithelial cells and pneumocytes, some clues can be gleaned from the local expression profile for the key endocytic proteins as evidenced by the Human Protein Atlas . These lines provide several key methodological advantages: they are well‐characterised, easy to maintain using standard cell culture protocols and retain the key characteristics of the primary cell type of origin. For emulation of the respiratory tract environment, the cell lines can be grown in an air–liquid interface culture as described before [A suitable starting model for initial investigation of SARS‐CoV‐2 endocytosis can involve established immortalised cell lines derived from the respiratory tract epithelium  involved in SARS‐CoV‐2 endocytosis, one can employ standard methods of multicolour fluorescence immunocytochemistry, light microscopy and colocalisation analysis. The proportion of the internalised virus colocalising with the classical markers of membrane trafficking compartments will indicate the intracellular itinerary of the virus . For thiFor a more detailed investigation of the endocytic route of the virus, viral infection can be combined with uptake of typical cargoes for different endocytic pathways. This approach would allow tracking of the virus in relation to other endocytic pathways and also to investigate the effect of viral infection on the general membrane trafficking network of the host cell. Suitable cargo molecules include transferrin for clathrin‐dependent endocytosis , choleraWhat is the relative contribution of different endocytic pathways to SARS‐CoV‐2 infection? To address this question, loss‐of‐function analysis can be performed, involving knockdown of the key regulatory proteins for different endocytic pathways, for example dynamin 2, caveolin‐1, flotillin‐1 and CtBP , 44  are on the World Health Organization’s List of Essential Medicines, ensuring their wide availability across the world. Also, several of the above have been tested (or are being tested) for topical delivery into the respiratory tract (Table Despite frenzied efforts to find effective treatments for COVID‐19, very little is currently known about the fundamental cell biology of the SARS‐CoV‐2 infection. The pivotal event underpinning SARS‐CoV‐2 infection is likely endocytosis of viral particles; therefore, blockade of this process may provide for a major therapeutic breakthrough. The tools of membrane trafficking research can be readily applied to rapidly characterise the endocytic route of virus entry in a cell‐based model of disease, providing a key insight into the disease mechanism (Fig. The generalised strategy of targeting the membrane trafficking of the host cell biology to prevent viral infection holds great promise for future therapeutic applications, considering the existence of other zoonotic coronaviruses capable of binding to human cells . More brThe authors declare no conflict of interest.