Acquiring Medical Statistical Competencies in a Demanding Evidence-Based World: Thoughts and Experience from a Student Statistical Team in a Mexican Academic Center

Training and encouraging students to critically review the evidence and make evidence-based decisions should be one of the goals of medical education. We report our experience developing an extracurricular university student statistical team that offer statistical aid to other students and faculty. This includes supervised training sessions and mentoring in diverse scientific research fields performed in our university

Impartición de estadística médica en escuelas de medicina: hacia una formación integral

El avance de la información científica y la consecuente complejidad estadística ha generado una mayor demanda en las habilidades de lectura crítica tanto en el profesional como en el estudiante

Supplementary Material: Diagnostic Tests for Differentiation between Cushing´s Syndrome and Non-Neoplastic Hypercortisolism: A Systematic Review and Meta-analysis

Context: Differential diagnosis between Cushing’s syndrome (CS) due to neoplastic endogenous hypercortisolism and non-neoplastic hypercortisolism (NNH, pseudo-Cushing’s syndrome) is crucial. Due to worldwide corticotropin-releasing hormone test CRH shortage, accuracy of alternative tests to Dexamethasone (Dex)-CRH is clearly needed. Objective: Asses the diagnostic accuracy of Dex-CRH, desmopressin stimulation test, midnight serum cortisol (MSC), and late-night salivary cortisol (LNSC) levels to distinguish CS from NNH. Methods: Articles through March 2022 were identified from Scopus, Web of Science, MEDLINE, EMBASE, and PubMed. All steps through the systematic review were performed independently and in duplicate and strictly adhered to the updated PRISMA-DTA checklist. Data Synthesis: A total of 26 articles (2059 patients) were included. Dex-CRH had a pooled sensitivity and specificity of 91% (95%CI 87-94%; I2 0%) and 82% (73-88%; I2 50%), desmopressin test 87% (81-91%; I2 34%) and 91% (85-94%; I2 15%), MSC 91% (85-94%; I2 65%) and 80% (70-88%; I2 70%), and LNSC 78% (66-86%; I2 54%) and 88% (83-92%; I2 36%), respectively. SROC areas under the curve were Dex-CRH 0.949, desmopressin test 0.941, MSC 0.939, and LNSC 0.940 without visual or statistical significance. The overall risk of studies bias was moderate. Conclusion: Dex-CRH, the desmopressin stimulation test, and MSC have similar diagnostic accuracy, with Dex-CRH and MSC having slightly higher sensitivity, and the desmopressin test being more specific. LNSC was the least accurate, probably due to high heterogeneity, intrinsic variability, different assays, and lack of consistent reported cutoffs. Our results should increase clinicians’ confidence when deciding which test to perform when facing this challenging differential diagnosis. Key Words: Cushing’s syndrome, neoplastic endogenous hypercortisolism, non-neoplastic hypercortisolism, pseudoCushing’s, dexamethasone CRH test, desmopressin test, salivary cortisol, midnight serum cortiso

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Diagnostic Accuracy of the Triglyceride and Glucose Index for Insulin Resistance: A Systematic Review

Introduction. The triglyceride and glucose (TyG) index has been described as a biochemical marker of insulin resistance (IR); however, its diagnostic accuracy remains uncertain. Objective. To summarize the evidence assessing the diagnostic accuracy of the TyG index regarding IR. Methods. A comprehensive search in MEDLINE, EMBASE, Web of Science, and Scopus was performed without any language restriction. Studies assessing the diagnostic accuracy of the TyG index against the hyperinsulinemic-euglycemic clamp (HIEC) or any other IR biochemical were assessed independently and in duplicate. Diagnostic accuracy measures (sensitivity, specificity, positive predictive value, negative predictive value, and likelihood ratios) were extracted independently and in duplicate. The QUADAS-2 tool was used to assess the risk of bias of independent studies. Results. We identified 15 eligible studies with 69,922 participants and an overall quality of low to moderate. The TyG index was evaluated by HIEC and HOMA as reference tests. The highest achieved sensitivity was 96% using HIEC, and the highest specificity was of 99% using HOMA-IR, with a cutoff value of 4.68. AUC values varied from 0.59 to 0.88. Cutoff values for IR were variable between studies, limiting its comparability. Conclusion. In this systematic review, we found moderate-to-low quality evidence about the usefulness of the TyG index as a surrogate biochemical marker of IR. Due to the lack of a standardized IR definition and heterogeneity between studies, further validation and standardized cutoff values are needed to be used in clinical practice

Multidrug-Resistant Tuberculosis and Its Association with Adrenal Insufficiency: Assessment with the Low-Dose ACTH Stimulation Test

Background. Multidrug-resistant tuberculosis (MDR-TB) is a major public health care concern that affects the life of millions of people around the world. The association of tuberculosis and adrenal insufficiency is well known; however, it is thought to be less prevalent every time. A spike in TB incidence and a lack of evidence of this association in patients with MDR-TB call for reassessment of an illness (adrenal dysfunction) that if not diagnosed could seriously jeopardize patients’ health. Objective. To determine the prevalence of adrenocortical insufficiency in patients with MDR-TB using the low-dose (1 μg) ACTH stimulation test at baseline and at 6–12 months of follow-up after antituberculosis treatment and culture conversion. Methods. A total of 48 men or women, aged ≥18 years (HIV-negative patients diagnosed with pulmonary MDR-TB) were included in this prospective observational study. Blood samples for serum cortisol were taken at baseline and 30 and 60 minutes after 1 μg ACTH stimulation at our tertiary level university hospital before and after antituberculosis treatment. Results. Forty-seven percent of subjects had primary MDR-TB; 43.8% had type 2 diabetes; none were HIV-positive. We found at enrollment 2 cases (4.2%) of adrenal insufficiency taking 500 nmol/L as the standard cutoff point value and 4 cases (8.3%) alternatively, using 550 nmol/L. After antituberculosis intensive phase drug-treatment and a negative mycobacterial culture (10.2±3.6 months) adrenocortical function was restored in all cases. Conclusions. In patients with MDR-TB, using the low-dose ACTH stimulation test, a low prevalence of mild adrenal insufficiency was observed. After antituberculosis treatment adrenal function was restored in all cases. Given the increasing and worrying epidemic of MDR-TB these findings have important clinical implications that may help clinicians and patients make better decisions when deciding to test for adrenocortical dysfunction or treat insufficient stimulated cortisol levels in the setting of MDR-TB

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

Background Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks. Methods The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned. Results A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31). Conclusion Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov)