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Background: Sun protection is recommended for skin cancer prevention, yet little is known about the role of sun protection on vitamin D levels. Our aim was to investigate the relationship between different types of sun protective behaviors and serum 25(OH)D levels in the general US population.Methods: Cross-sectional, nationally representative survey of 5,920 adults aged 18-60 years in the US National Health and Nutrition Examination Survey 2003-2006. We analyzed questionnaire responses on sun protective behaviors: staying in the shade, wearing long sleeves, wearing a hat, using sunscreen and SPF level. Analyses were adjusted for multiple confounders of 25(OH)D levels and stratified by race. Our primary outcome measures were serum 25(OH)D levels (ng/ml) measured by radioimmunoassay and vitamin D deficiency, defined as 25(OH)D levels <20 ng/ml.Results: Staying in the shade and wearing long sleeves were significantly associated with lower 25(OH)D levels. Subjects who reported frequent use of shade on a sunny day had -3.5 ng/ml (p (trend) < 0.001) lower 25(OH)D levels compared to subjects who reported rare use. Subjects who reported frequent use of long sleeves had -2.2 ng/ml (p (trend) = 0.001) lower 25(OH)D levels. These associations were strongest for whites, and did not reach statistical significance among Hispanics or blacks. White participants who reported frequently staying in the shade or wearing long sleeves had double the odds of vitamin D deficiency compared with those who rarely did so. Neither wearing a hat nor using sunscreen was associated with low 25(OH)D levels or vitamin D deficiency.Conclusions: White individuals who protect themselves from the sun by seeking shade or wearing long sleeves may have lower 25(OH)D levels and be at risk for vitamin D deficiency. Frequent sunscreen use does not appear to be linked to vitamin D deficiency in this population. [ABSTRACT FROM AUTHOR]

Introduction: Although the female athlete triad (Triad) has been associated with increased risk of bone-stress injuries (BSIs), limited research among collegiate athletes has addressed the associations between the Triad and non-BSI injuries., Objective: To elucidate the relationship between Triad and both BSI and non-BSI in female athletes., Design: Retrospective cohort study., Setting: Primary and tertiary care student athlete clinic., Participants: National Collegiate Athletic Association Division I female athletes at a single institution., Intervention: Participants completed a pre-participation questionnaire and dual-energy x-ray absorptiometry, which was used to generate a Triad cumulative risk assessment score (Triad score). The number of overuse musculoskeletal injuries that occurred while the athletes were still competing collegiately were identified through chart review., Main Outcome Measure: BSI and non-BSI were treated as count variables. The association between BSI, non-BSI, and Triad score was measured using Poisson regression to calculate rate ratios., Results: Of 239 athletes, 43% of athletes (n = 103) sustained at least one injury. Of those, 40% (n = 95) sustained at least one non-BSI and 10% (n = 24) sustained at least one BSI over an average follow-up 2.5 years. After accounting for sport type (non-lean, runner, other endurance sport, or other lean advantage sport) and baseline age, we found that every additional Triad score risk point was associated with a significant 17% increase in the rate of BSI (rate ratio [RR] 1.17, 95% confidence interval [CI] 1.03-1.33; p = .016). However, Triad score was unrelated to non-BSI (1.00, 95% CI 0.91-1.11; p = .99). Compared with athletes in non-lean sports (n = 108), athletes in other lean advantage sports (n = 30) had an increased rate of non-BSI (RR: 2.09, p = .004) whereas distance runners (n = 46) had increased rates of BSI (RR: 7.65, p < .001) and non-BSI (RR: 2.25, p < .001)., Conclusions: Higher Triad score is associated with an increased risk of BSI but not non-BSI in collegiate athletes., (© 2024 American Academy of Physical Medicine and Rehabilitation.)

Objectives: A "null field" is a scientific field where there is nothing to discover and where observed associations are thus expected to simply reflect the magnitude of bias. We aimed to characterize a null field using a known example, homeopathy (a pseudoscientific medical approach based on using highly diluted substances), as a prototype., Study Design and Setting: We identified 50 randomized placebo-controlled trials of homeopathy interventions from highly cited meta-analyses. The primary outcome variable was the observed effect size in the studies. Variables related to study quality or impact were also extracted., Results: The mean effect size for homeopathy was 0.36 standard deviations (Hedges' g; 95% confidence interval: 0.21, 0.51) better than placebo, which corresponds to an odds ratio of 1.94 (95% CI: 1.69, 2.23) in favor of homeopathy. 80% of studies had positive effect sizes (favoring homeopathy). Effect size was significantly correlated with citation counts from journals in the directory of open-access journals and CiteWatch. We identified common statistical errors in 25 studies., Conclusion: A null field like homeopathy can exhibit large effect sizes, high rates of favorable results, and high citation impact in the published scientific literature. Null fields may represent a useful negative control for the scientific process., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Objective: Meta-analysis and meta-regression are often highly cited and may influence practice. Unfortunately, statistical errors in meta-analyses are widespread and can lead to flawed conclusions. The purpose of this article was to review common statistical errors in meta-analyses and to document their frequency in highly cited meta-analyses from strength and conditioning research., Methods: We identified five errors in one highly cited meta-regression from strength and conditioning research: implausible outliers; overestimated effect sizes that arise from confusing standard deviation with standard error; failure to account for correlated observations; failure to account for within-study variance; and a focus on within-group rather than between-group results. We then quantified the frequency of these errors in 20 of the most highly cited meta-analyses in the field of strength and conditioning research from the past 20 years., Results: We found that 85% of the 20 most highly cited meta-analyses in strength and conditioning research contained statistical errors. Almost half (45%) contained at least one effect size that was mistakenly calculated using standard error rather than standard deviation. In several cases, this resulted in obviously wrong effect sizes, for example, effect sizes of 11 or 14 standard deviations. Additionally, 45% failed to account for correlated observations despite including numerous effect sizes from the same study and often from the same group within the same study., Conclusions: Statistical errors in meta-analysis and meta-regression are common in strength and conditioning research. We highlight five errors that authors, editors, and readers should check for when preparing or critically reviewing meta-analyses., (© 2022. The Author(s).)

Background: Bone stress injuries (BSIs) are common in athletes. Risk factors for BSI may differ by skeletal anatomy and relative contribution of trabecular-rich and cortical-rich bone., Hypothesis: We hypothesized that Female Athlete Triad (Triad) risk factors would be more strongly associated with BSIs sustained at trabecular-rich versus cortical-rich skeletal sites., Study Design: Cohort study; Level of evidence, 2., Methods: The study population comprised 321 female National Collegiate Athletic Association Division I athletes participating in 16 sports from 2008 to 2014. Triad risk factors and a Triad cumulative risk score were assessed using responses to preparticipation examination and dual energy x-ray absorptiometry to measure lumbar spine and whole-body bone mineral density (BMD). Sports-related BSIs were diagnosed by a physician and confirmed radiologically. Athletes were grouped into those sustaining a subsequent trabecular-rich BSI, a subsequent cortical-rich BSI, and those without a BSI. Data were analyzed with multinomial logistic regression adjusted for participation in cross-country running versus other sports., Results: A total of 19 participants sustained a cortical-rich BSI (6%) and 10 sustained a trabecular-rich BSI (3%) over the course of collegiate sports participation. The Triad cumulative risk score was significantly related to both trabecular-rich and cortical-rich BSI. However, lower BMD and weight were associated with significantly greater risk for trabecular-rich than cortical-rich BSIs. For every value lower than 1 SD, the odds ratios (95% CIs) for trabecular-rich versus cortical-rich BSI were 3.08 (1.25-7.56) for spine BMD; 2.38 (1.22-4.64) for whole-body BMD; and 5.26 (1.48-18.70) for weight. Taller height was a significantly better predictor of cortical-rich than trabecular-rich BSI., Conclusion: The Triad cumulative risk score was significantly associated with both trabecular-rich and cortical-rich BSI, but Triad-related risk factors appeared more strongly related to trabecular-rich BSI. In particular, low BMD and low weight were associated with significantly higher increases in the risk of trabecular-rich BSI than cortical-rich BSI. These findings suggest Triad risk factors are more common in athletes sustaining BSI in trabecular-rich than cortical-rich locations., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: A.S.T. has received research support from DJO and Uniform Health Services. M.F. has received consulting fees from Ipsen Bioscience and honoraria from Fidia Pharma. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2022.)

Sun exposure is a risk factor for skin cancer. Knowledge and behaviors around sun exposure protective measures are poorly described in athletes including runners. Our primary objective was to describe sun exposure behaviors and knowledge in a population of runners. A cross-sectional online survey was administered to 697 runners to measure the frequency of seven sun protective behaviors: sunscreen use on the face or body; wearing a hat, sunglasses, or long sleeves; running in shade; and avoidance of midday running. Between 54% and 84% of runners reported that they engaged in these behaviors at least sometimes, but only 7% to 45% reported frequent use. Of 525 runners who gave a primary reason for not using sunscreen regularly, 49.0% cited forgetfulness; 17.3% cited discomfort; and only a small percentage cited maintaining a tan (6.1%) or optimizing vitamin D (5.1%). Of 689 runners who responded to a question about what factor most influences their overall sun exposure habits, 39.2% cited fear of skin cancer, 28.7% cited comfort level, and 15.8% cited fear of skin aging. In addition to the seven individual behaviors, we also asked runners how frequently they took precautions to protect against the sun overall. We explored associations between participant characteristics and the overall use of sun protection using ordinal logistic regression. Overall, sun protection was used more frequently in runners who were female, older, or had a history of skin cancer. Runners appear to recognize the importance of sun protection and the potential consequences of not using it, but report forgetfulness and discomfort as the biggest barriers to consistent use. Interventions using habit-formation strategies and self-regulation training may prove to be most useful in closing this gap between knowledge and practice.

Background and Purpose: Prediction models for functional outcomes after ischemic stroke are useful for statistical analyses in clinical trials and guiding patient expectations. While there are models predicting dichotomous functional outcomes after ischemic stroke, there are no models that predict ordinal mRS outcomes. We aimed to create a model that predicts, at the time of hospital discharge, a patient's modified Rankin Scale (mRS) score on day 90 after ischemic stroke. Methods: We used data from three multi-center prospective studies: CRISP, DEFUSE 2, and DEFUSE 3 to derive and validate an ordinal logistic regression model that predicts the 90-day mRS score based on variables available during the stroke hospitalization. Forward selection was used to retain independent significant variables in the multivariable model. Results: The prediction model was derived using data on 297 stroke patients from the CRISP and DEFUSE 2 studies. National Institutes of Health Stroke Scale (NIHSS) at discharge and age were retained as significant ( p < 0.001) independent predictors of the 90-day mRS score. When applied to the external validation set (DEFUSE 3, n = 160), the model accurately predicted the 90-day mRS score within one point for 78% of the patients in the validation cohort. Conclusions: A simple model using age and NIHSS score at time of discharge can predict 90-day mRS scores in patients with ischemic stroke. This model can be useful for prognostication in routine clinical care and to impute missing data in clinical trials., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Mlynash, Sainani, Albers and Lansberg.)

Introduction: Determinants of bone health and injury are important to identify in athletes. Bone mineral density (BMD) is commonly measured in athletes with Female Athlete Triad (Triad) risk factors; the trabecular bone score (TBS) has been proposed to predict fracture risk independent of BMD. Evaluation of TBS and spine BMD in relation bone stress injury (BSI) risk has not been studied in female collegiate athletes., Objective: We hypothesized that spine BMD and TBS would each independently predict BSI and that the combined measures would improve injury prediction in female collegiate athletes. We also hypothesized that each measure would be correlated with Triad risk factors., Design: Retrospective cohort., Setting: Academic Institution., Methods: Dual energy x-ray absorptiometry (DXA) of the lumbar spine was used to calculate BMD and TBS values. Chart review was used to identify BSI that occurred after the DXA measurement and to obtain Triad risk factors. We used logistic regression to examine the ability of TBS and BMD alone or in combination to predict prospective BSI., Results: Within 321 athletes, 29 (9.0%) sustained a BSI after DXA. BMD and TBS were highly correlated (Pearson correlation r = 0.62, P < .0001). Spine BMD and TBS had similar ability to predict BSI; the C-statistic and 95% confidence intervals were 0.69 (0.58 to 0.81) for spine BMD versus 0.68 (0.57 to 0.79) for TBS. No improvement in discrimination was observed with combined BMD + TBS (C-statistic 0.70, 0.59 to 0.81). Both TBS and BMD predicted trabecular-rich BSI (defined as pelvis, femoral neck, and calcaneus) better than cortical-rich BSI. Both measures had similar correlations with Triad risk factors., Conclusion: Lower BMD and TBS values are associated with elevated risk for BSI and similar correlation to Triad risk factors. TBS does not improve prediction of BSI. Collectively, our findings suggest that BMD may be a sufficient measure of skeletal integrity from DXA in female collegiate athletes., (© 2020 American Academy of Physical Medicine and Rehabilitation.)

Competing Interests: Competing interests: None declared.

Magnitude-based inference (MBI) is a controversial statistical method that has been used in hundreds of papers in sports science despite criticism from statisticians. To better understand how this method has been applied in practice, we systematically reviewed 232 papers that used MBI. We extracted data on study design, sample size, and choice of MBI settings and parameters. Median sample size was 10 per group (interquartile range, IQR: 8-15) for multi-group studies and 14 (IQR: 10-24) for single-group studies; few studies reported a priori sample size calculations (15%). Authors predominantly applied MBI's default settings and chose "mechanistic/non-clinical" rather than "clinical" MBI even when testing clinical interventions (only 16 studies out of 232 used clinical MBI). Using these data, we can estimate the Type I error rates for the typical MBI study. Authors frequently made dichotomous claims about effects based on the MBI criterion of a "likely" effect and sometimes based on the MBI criterion of a "possible" effect. When the sample size is n = 8 to 15 per group, these inferences have Type I error rates of 12%-22% and 22%-45%, respectively. High Type I error rates were compounded by multiple testing: Authors reported results from a median of 30 tests related to outcomes; and few studies specified a primary outcome (14%). We conclude that MBI has promoted small studies, promulgated a "black box" approach to statistics, and led to numerous papers where the conclusions are not supported by the data. Amidst debates over the role of p-values and significance testing in science, MBI also provides an important natural experiment: we find no evidence that moving researchers away from p-values or null hypothesis significance testing makes them less prone to dichotomization or over-interpretation of findings., Competing Interests: The authors have declared that no competing interests exist.

Background: Vaccine hesitancy, the reluctance or refusal to receive vaccination, is a growing public health problem in the United States and globally. State policies that eliminate nonmedical ("personal belief") exemptions to childhood vaccination requirements are controversial, and their effectiveness to improve vaccination coverage remains unclear given limited rigorous policy analysis. In 2016, a California policy (Senate Bill 277) eliminated nonmedical exemptions from school entry requirements. The objective of this study was to estimate the association between California's 2016 policy and changes in vaccine coverage., Methods and Findings: We used a quasi-experimental state-level synthetic control analysis and a county-level difference-in-differences analysis to estimate the impact of the 2016 California policy on vaccination coverage and prevalence of exemptions to vaccine requirements (nonmedical and medical). We used publicly available state-level data from the US Centers for Disease Control and Prevention on coverage of measles, mumps, and rubella (MMR) vaccination, nonmedical exemption, and medical exemption in children entering kindergarten. We used county-level data individually requested from state departments of public health on overall vaccine coverage and exemptions. Based on data availability, we included state-level data for 45 states, including California, from 2011 to 2017 and county-level data for 17 states from 2010 to 2017. The prespecified primary study outcome was MMR vaccination in the state analysis and overall vaccine coverage in the county analysis. In the state-level synthetic control analysis, MMR coverage in California increased by 3.3% relative to its synthetic control in the postpolicy period (top 2 of 43 states evaluated in the placebo tests, top 5%), nonmedical exemptions decreased by 2.4% (top 2 of 43 states evaluated in the placebo tests, top 5%), and medical exemptions increased by 0.4% (top 1 of 44 states evaluated in the placebo tests, top 2%). In the county-level analysis, overall vaccination coverage increased by 4.3% (95% confidence interval [CI] 2.9%-5.8%, p < 0.001), nonmedical exemptions decreased by 3.9% (95% CI 2.4%-5.4%, p < 0.001), and medical exemptions increased by 2.4% (95% CI 2.0%-2.9%, p < 0.001). Changes in vaccination coverage across counties after the policy implementation from 2015 to 2017 ranged from -6% to 26%, with larger increases in coverage in counties with lower prepolicy vaccine coverage. Results were robust to alternative model specifications. The limitations of the study were the exclusion of a subset of US states from the analysis and the use of only 2 years of postpolicy data based on data availability., Conclusions: In this study, implementation of the California policy that eliminated nonmedical childhood vaccine exemptions was associated with an estimated increase in vaccination coverage and a reduction in nonmedical exemptions at state and county levels. The observed increase in medical exemptions was offset by the larger reduction in nonmedical exemptions. The largest increases in vaccine coverage were observed in the most "high-risk" counties, meaning those with the lowest prepolicy vaccine coverage. Our findings suggest that government policies removing nonmedical exemptions can be effective at increasing vaccination coverage., Competing Interests: I have read the journal's policy and the authors of this manuscript have the following competing interests: NCL reports funding from the World Health Organization for work outside of the current study. No other authors have competing interests.

Objectives: This study quantified the change in blood pressure (BP) during antivascular endothelial growth factor (VEGF) tyrosine kinase inhibitor (TKI) therapy, compared BPs between TKIs, and analyzed change in BP during antihypertensive therapy., Background: TKIs targeting VEGF are associated with hypertension. The absolute change in BP during anti-VEGF TKI treatment is not well characterized outside clinical trials., Methods: A retrospective single-center study included patients with metastatic renal cell carcinoma who received anti-VEGF TKIs between 2007 and 2018. Mixed models analyzed 3,088 BPs measured at oncology clinics., Results: In 228 patients (baseline systolic blood pressure [SBP] 130.2 ± 16.3 mm Hg, diastolic blood pressure [DBP] 76.8 ± 9.3 mm Hg), anti-VEGF TKIs were associated with mean increases in SBP of 8.5 mm Hg (p < 0.0001) and DBP of 6.7 mm Hg (p <0.0001). Of the anti-VEGF TKIs evaluated, axitinib was associated with the greatest BP increase, with an increase in SBP of 12.6 mm Hg (p < 0.0001) and in DBP of 10.3 mm Hg (p < 0.0001) relative to baseline. In pairwise comparisons between agents, axitinib was associated with greater SBPs than cabozantinib by 8.4 mm Hg (p = 0.004) and pazopanib by 5.1 mm Hg (p = 0.01). Subsequent anti-VEGF TKI courses were associated with small increases in DBP, but not SBP, relative to the first course. During anti-VEGF TKI therapy, calcium-channel blockers and potassium-sparing diuretic agents were associated with the largest BP reductions, with decreases in SBP of 5.6 mm Hg (p < 0.0001) and 9.9 mm Hg (p = 0.007), respectively., Conclusions: Anti-VEGF TKIs are associated with increased BP; greatest increases are observed with axitinib. Calcium-channel blockers and potassium-sparing diuretic agents were associated with the largest reductions in BP., (© 2019 The Authors.)

Objectives: Bone stress injuries (BSI) are common in runners of both sexes. The purpose of this study was to determine if a modified Female Athlete Triad Cumulative Risk Assessment tool would predict BSI in male distance runners., Methods: 156 male runners at two collegiate programmes were studied using mixed retrospective and prospective design for a total of 7 years. Point values were assigned using risk assessment categories including low energy availability, low body mass index (BMI), low bone mineral density (BMD) and prior BSI. The outcome was subsequent development of BSI. Statistical models used a mixed effects Poisson regression model with p<0.05 as threshold for significance. Two regression analyses were performed: (1) baseline risk factors as the independent variable; and (2) annual change in risk factors (longitudinal data) as the independent variable., Results: 42/156 runners (27%) sustained 61 BSIs over an average 1.9 years of follow-up. In the baseline risk factor model, each 1 point increase in prior BSI score was associated with a 57% increased risk for prospective BSI (p=0.0042) and each 1 point increase in cumulative risk score was associated with a 37% increase in prospective BSI risk (p=0.0079). In the longitudinal model, each 1 point increase in cumulative risk score was associated with a 27% increase in prospective BSI risk (p=0.05). BMI (rate ratio (RR)=1.91, p=0.11) and BMD (RR=1.58, p=0.19) risk scores were not associated with BSI., Conclusion: A modified cumulative risk assessment tool may help identify male runners at elevated risk for BSI. Identifying risk factors may guide treatment and prevention strategies., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Athletes in weight-bearing sports may benefit from higher bone mineral density (BMD). However, some athletes are at risk for impaired BMD with female athlete triad (Triad). The purpose of this study is to understand the influence of sports participation and Triad on BMD. We hypothesize that athletes in high-impact and multidirectional loading sports will have highest BMD, whereas nonimpact and low-impact sports will have lowest BMD. Triad risk factors are expected to reduce BMD values independent of sports participation., Methods: Two hundred thirty-nine female athletes participating in 16 collegiate sports completed dual-energy x-ray absorptiometry (DXA) scans to measure BMD z-scores of the lumbar spine (LS) and total body (TB). Height and weight were measured to calculate body mass index (BMI). Triad risk assessment variables were obtained from preparticipation examination. Mean BMD z-scores were compared between sports and by sport category (high-impact, multidirectional, low-impact, and nonimpact). Multivariable regression analyses were performed to identify differences of BMD z-scores accounting for Triad and body size/composition., Results: Athlete populations with lowest average BMD z-scores included synchronized swimming (LS, -0.34; TB, 0.21) swimming/diving (LS, 0.34; TB, -0.06), crew/rowing (LS, 0.27; TB, 0.62), and cross-country (LS, 0.29; TB, 0.91). Highest values were in gymnastics (LS, 1.96; TB, 1.37), volleyball (LS, 1.90; TB, 1.74), basketball (LS, 1.73; TB, 1.99), and softball (LS, 1.68; TB, 1.78). All Triad risk factors were associated with lower BMD z-scores in univariable analyses; only low BMI and oligomenorrhea/amenorrhea were associated in multivariable analyses (all P < 0.05). Accounting for Triad risk factors and body size/composition, high-impact sports were associated with higher LS and TB BMD z-scores and nonimpact sports with lower LS and TB BMD z-scores compared to low-impact sport (all P < 0.05)., Conclusions: Both sport type and Triad risk factors influence BMD. Athletes in low-impact and nonimpact sports and athletes with low BMI and oligomenorrhea/amenorrhea are at highest risk for reduced BMD.

Objective: The effects of in-utero HIV-exposure on infectious morbidity and mortality in settings with universal maternal treatment and high breastfeeding rates are unclear. Further, the benefits of exclusive feeding options have not been assessed in the Option B+ era. We investigated these in two African settings with high breastfeeding uptake and good HIV treatment infrastructure during the first year of life., Methods: Cox regression with time-changing variables in a birth cohort of 749 HIV-exposed uninfected and HIV-unexposed uninfected infants from Cape Town, South Africa and Jos, Nigeria., Results: There was no difference in infectious morbidity incidence between HIV-exposed uninfected and HIV-unexposed uninfected infants (hazard ratio 1.01; 95% CI 0.78-1.32) after adjusting for confounding variables. Formula-fed infants had significantly higher infectious morbidity incidence when compared with exclusively breastfed infants (hazard ratio 1.64; 95% CI 1.03-2.63) and mixed-breastfed infants (hazard ratio 1.42; 95% CI 1.00-2.02) after adjusting for potential confounding variables. There was no significant difference in mortality among HIV-exposed infants and HIV-unexposed infants during the first year of life in this cohort (2.04 versus 0.94%, P = 0.38). Notably, exclusive breastfeeding for only 4 months had protective effects on morbidity up to 1 year., Conclusion: In settings with universal antiretroviral coverage and high breastfeeding rates, breastfeeding mitigates the effects of in-utero HIV exposure among infants during the first year of life. These findings support previous recommendations for exclusive breastfeeding among HIV-infected women and highlight the role that breastfeeding plays on the health of infants in settings where exclusive breastfeeding is not always feasible or where replacement feeding is recommended.

Purpose: A statistical method called "magnitude-based inference" (MBI) has gained a following in the sports science literature, despite concerns voiced by statisticians. Its proponents have claimed that MBI exhibits superior type I and type II error rates compared with standard null hypothesis testing for most cases. I have performed a reanalysis to evaluate this claim., Methods: Using simulation code provided by MBI's proponents, I estimated type I and type II error rates for clinical and nonclinical MBI for a range of effect sizes, sample sizes, and smallest important effects. I plotted these results in a way that makes transparent the empirical behavior of MBI. I also reran the simulations after correcting mistakes in the definitions of type I and type II error provided by MBI's proponents. Finally, I confirmed the findings mathematically; and I provide general equations for calculating MBI's error rates without the need for simulation., Results: Contrary to what MBI's proponents have claimed, MBI does not exhibit "superior" type I and type II error rates to standard null hypothesis testing. As expected, there is a tradeoff between type I and type II error. At precisely the small-to-moderate sample sizes that MBI's proponents deem "optimal," MBI reduces the type II error rate at the cost of greatly inflating the type I error rate-to two to six times that of standard hypothesis testing., Conclusions: Magnitude-based inference exhibits worrisome empirical behavior. In contrast to standard null hypothesis testing, which has predictable type I error rates, the type I error rates for MBI vary widely depending on the sample size and choice of smallest important effect, and are often unacceptably high. Magnitude-based inference should not be used.

Background and Objective: Semantic memory measures may be useful in tracking and predicting progression of Alzheimer disease. We investigated relationships among semantic memory tasks and their 1-year predictive value in women with Alzheimer disease., Methods: We conducted secondary analyses of a randomized clinical trial of raloxifene in 42 women with late-onset mild-to-moderate Alzheimer disease. We assessed semantic memory with tests of oral confrontation naming, category fluency, semantic recognition and semantic naming, and semantic density in written narrative discourse. We measured global cognition (Alzheimer Disease Assessment Scale, cognitive subscale), dementia severity (Clinical Dementia Rating sum of boxes), and daily function (Activities of Daily Living Inventory) at baseline and 1 year., Results: At baseline and 1 year, most semantic memory scores correlated highly or moderately with each other and with global cognition, dementia severity, and daily function. Semantic memory task performance at 1 year had worsened one-third to one-half standard deviation. Factor analysis of baseline test scores distinguished processes in semantic and lexical retrieval (semantic recognition, semantic naming, confrontation naming) from processes in lexical search (semantic density, category fluency). The semantic-lexical retrieval factor predicted global cognition at 1 year. Considered separately, baseline confrontation naming and category fluency predicted dementia severity, while semantic recognition and a composite of semantic recognition and semantic naming predicted global cognition. No individual semantic memory test predicted daily function., Conclusions: Semantic-lexical retrieval and lexical search may represent distinct aspects of semantic memory. Semantic memory processes are sensitive to cognitive decline and dementia severity in Alzheimer disease.

Importance: Many published randomized clinical trials (RCTs) make claims for subgroup differences., Objective: To evaluate how often subgroup claims reported in the abstracts of RCTs are actually supported by statistical evidence (P < .05 from an interaction test) and corroborated by subsequent RCTs and meta-analyses., Data Sources: This meta-epidemiological survey examines data sets of trials with at least 1 subgroup claim, including Subgroup Analysis of Trials Is Rarely Easy (SATIRE) articles and Discontinuation of Randomized Trials (DISCO) articles. We used Scopus (updated July 2016) to search for English-language articles citing each of the eligible index articles with at least 1 subgroup finding in the abstract., Study Selection: Articles with a subgroup claim in the abstract with or without evidence of statistical heterogeneity (P < .05 from an interaction test) in the text and articles attempting to corroborate the subgroup findings., Data Extraction and Synthesis: Study characteristics of trials with at least 1 subgroup claim in the abstract were recorded. Two reviewers extracted the data necessary to calculate subgroup-level effect sizes, standard errors, and the P values for interaction. For individual RCTs and meta-analyses that attempted to corroborate the subgroup findings from the index articles, trial characteristics were extracted. Cochran Q test was used to reevaluate heterogeneity with the data from all available trials., Main Outcomes and Measures: The number of subgroup claims in the abstracts of RCTs, the number of subgroup claims in the abstracts of RCTs with statistical support (subgroup findings), and the number of subgroup findings corroborated by subsequent RCTs and meta-analyses., Results: Sixty-four eligible RCTs made a total of 117 subgroup claims in their abstracts. Of these 117 claims, only 46 (39.3%) in 33 articles had evidence of statistically significant heterogeneity from a test for interaction. In addition, out of these 46 subgroup findings, only 16 (34.8%) ensured balance between randomization groups within the subgroups (eg, through stratified randomization), 13 (28.3%) entailed a prespecified subgroup analysis, and 1 (2.2%) was adjusted for multiple testing. Only 5 (10.9%) of the 46 subgroup findings had at least 1 subsequent pure corroboration attempt by a meta-analysis or an RCT. In all 5 cases, the corroboration attempts found no evidence of a statistically significant subgroup effect. In addition, all effect sizes from meta-analyses were attenuated toward the null., Conclusions and Relevance: A minority of subgroup claims made in the abstracts of RCTs are supported by their own data (ie, a significant interaction effect). For those that have statistical support (P < .05 from an interaction test), most fail to meet other best practices for subgroup tests, including prespecification, stratified randomization, and adjustment for multiple testing. Attempts to corroborate statistically significant subgroup differences are rare; when done, the initially observed subgroup differences are not reproduced.

Background: The female athlete triad (referred to as the triad) contributes to adverse health outcomes, including bone stress injuries (BSIs), in female athletes. Guidelines were published in 2014 for clinical management of athletes affected by the triad., Purpose: This study aimed to (1) classify athletes from a collegiate population of 16 sports into low-, moderate-, and high-risk categories using the Female Athlete Triad Cumulative Risk Assessment score and (2) evaluate the predictive value of the risk categories for subsequent BSIs., Study Design: Cohort study; Level of evidence, 3., Methods: A total of 323 athletes completed both electronic preparticipation physical examination and dual-energy x-ray absorptiometry scans. Of these, 239 athletes with known oligomenorrhea/amenorrhea status were assigned to a low-, moderate-, or high-risk category. Chart review was used to identify athletes who sustained a subsequent BSI during collegiate sports participation; the injury required a physician diagnosis and imaging confirmation., Results: Of 239 athletes, 61 (25.5%) were classified into moderate-risk and 9 (3.8%) into high-risk categories. Sports with the highest proportion of athletes assigned to the moderate- and high-risk categories included gymnastics (56.3%), lacrosse (50%), cross-country (48.9%), swimming/diving (42.9%), sailing (33%), and volleyball (33%). Twenty-five athletes (10.5%) assigned to risk categories sustained ≥1 BSI. Cross-country runners contributed the majority of BSIs (16; 64%). After adjusting for age and participation in cross-country, we found that moderate-risk athletes were twice as likely as low-risk athletes to sustain a BSI (risk ratio [RR], 2.6; 95% confidence interval [95% CI], 1.3-5.5) and high-risk athletes were nearly 4 times as likely (RR, 3.8; 95% CI, 1.8-8.0). When examining the 6 individual components of the triad risk assessment score, both the oligomenorrhea/amenorrhea score ( P = .0069) and the prior stress fracture/reaction score ( P = .0315) were identified as independent predictors for subsequent BSIs (after adjusting for cross-country participation and age)., Conclusion: Using published guidelines, 29% of female collegiate athletes in this study were classified into moderate- or high-risk categories using the Female Athlete Triad Cumulative Risk Assessment Score. Moderate- and high-risk athletes were more likely to subsequently sustain a BSI; most BSIs were sustained by cross-country runners.

Objective: To determine whether raloxifene, a selective estrogen receptor modulator, improves cognitive function compared with placebo in women with Alzheimer disease (AD) and to provide an estimate of cognitive effect., Methods: This pilot study was conducted as a randomized, double-blind, placebo-controlled trial, with a planned treatment of 12 months. Women with late-onset AD of mild to moderate severity were randomly allocated to high-dose (120 mg) oral raloxifene or identical placebo provided once daily. The primary outcome compared between treatment groups at 12 months was change in the Alzheimer's Disease Assessment Scale, cognitive subscale (ADAS-cog)., Results: Forty-two women randomized to raloxifene or placebo were included in intent-to-treat analyses (mean age 76 years, range 68-84), and 39 women contributed 12-month outcomes. ADAS-cog change scores at 12 months did not differ significantly between treatment groups (standardized difference 0.03, 95% confidence interval -0.39 to 0.44, 2-tailed p = 0.89). Raloxifene and placebo groups did not differ significantly on secondary analyses of dementia rating, activities of daily living, behavior, or a global cognition composite score. Caregiver burden and caregiver distress were similar in both groups., Conclusions: Results on the primary outcome showed no cognitive benefits in the raloxifene-treated group., Classification of Evidence: This study provides Class I evidence that for women with AD, raloxifene does not have a significant cognitive effect. The study lacked the precision to exclude a small effect., (© 2015 American Academy of Neurology.)

Objective: To test the hypothesis that obstructive sleep apnea (OSA) is a risk factor for development of postoperative atrial fibrillation (POAF) after cardiac surgery., Design: Retrospective analysis., Setting: Single-center university hospital., Participants: Five hundred forty-five patients in sinus rhythm preoperatively undergoing coronary artery bypass grafting (CABG), aortic valve replacement, mitral valve replacement/repair, or combined valve/CABG surgery from January 2008 to April 2011., Interventions: Retrospective review of medical records., Measurements and Main Results: Postoperative atrial fibrillation was defined as atrial fibrillation requiring therapeutic intervention. Of 545 cardiac surgical patients, 226 (41%) patients developed POAF. The risk was higher in 72 OSA patients than 473 patients without OSA (67% v 38%, adjusted hazard ratio 1.83 [95% CI: 1.30-2.58], p<0.001). Of the 32 OSA patients who used home positive airway pressure (PAP) therapy, 18 (56%) developed POAF compared with 29 of 38 (76%) patients who did not use PAP at home (unadjusted hazard ratio 0.63 [95% CI: 0.35-1.15], p = 0.13)., Conclusion: OSA is significantly associated with POAF in cardiac surgery patients. Further investigation is needed to determine whether or not use of positive airway pressure in OSA patients reduces the risk of POAF., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Adolescent runners may be at risk for low bone mineral density (BMD) associated with sports participation. Few prior investigations have evaluated bone health in young runners, particularly males., Purpose: To characterize sex-specific risk factors for low BMD in adolescent runners., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Training characteristics, fracture history, eating behaviors and attitudes, and menstrual history were measured using online questionnaires. A food frequency questionnaire was used to identify dietary patterns and measure calcium intake. Runners (female: n = 94, male: n = 42) completed dual-energy x-ray absorptiometry (DXA) to measure lumbar spine (LS) and total body less head (TBLH) BMD and body composition values, including android-to-gynoid (A:G) fat mass ratio. The BMD was standardized to Z-scores using age, sex, and race/ethnicity reference values. Questionnaire values were combined with DXA values to determine risk factors associated with differences in BMD Z-scores in LS and TBLH and low bone mass (defined as BMD Z-score ≤-1)., Results: In multivariable analyses, risk factors for lower LS BMD Z-scores in girls included lower A:G ratio, being shorter, and the combination of (interaction between) current menstrual irregularity and a history of fracture (all P < .01). Later age of menarche, lower A:G ratio, lower lean mass, and drinking less milk were associated with lower TBLH BMD Z-scores (P < .01). In boys, lower body mass index (BMI) Z-scores and the belief that being thinner improves performance were associated with lower LS and TBLH BMD Z-scores (all P < .05); lower A:G ratio was additionally associated with lower TBLH Z-scores (P < .01). Thirteen girls (14%) and 9 boys (21%) had low bone mass. Girls with a BMI ≤17.5 kg/m(2) or both menstrual irregularity and a history of fracture were significantly more likely to have low bone mass. Boys with a BMI ≤17.5 kg/m(2) and belief that thinness improves performance were significantly more likely to have low bone mass., Conclusion: This study identified sex-specific risk factors for impaired bone mass in adolescent runners. These risk factors can be helpful to guide sports medicine professionals in evaluation and management of young runners at risk for impaired bone health., (© 2015 The Author(s).)

Background: Running is a popular sport that may be performed safely during pregnancy. Few studies have characterized running behavior of competitive female runners during pregnancy and breastfeeding., Hypothesis: Women modify their running behavior during pregnancy and breastfeeding., Study Design: Observational, cross-sectional study., Level of Evidence: Level 2., Methods: One hundred ten female long-distance runners who ran competitively prior to pregnancy completed an online survey characterizing training attitudes and behaviors during pregnancy and postpartum., Results: Seventy percent of runners ran some time during their pregnancy (or pregnancies), but only 31% ran during their third trimester. On average, women reduced training during pregnancy, including cutting their intensity to about half of their nonpregnant running effort. Only 3.9% reported sustaining a running injury while pregnant. Fewer than one third (29.9%) selected fetal health as a reason to continue running during pregnancy. Of the women who breastfed, 84.1% reported running during breastfeeding. Most felt that running had no effect on their ability to breastfeed. Women who ran during breastfeeding were less likely to report postpartum depression than those who did not run (6.7% vs 23.5%, P = 0.051), but we did not detect the same association of running during pregnancy (6.5% vs 15.2%, P = 0.16)., Conclusion: Women runners reported a reduction in total training while pregnant, and few sustained running injuries during pregnancy. The effect of running on postpartum depression was not clear from our findings., Clinical Relevance: We characterized running behaviors during pregnancy and breastfeeding in competitive runners. Most continue to run during pregnancy but reduce total training effort. Top reasons for running during pregnancy were fitness, health, and maintaining routine; the most common reason for not running was not feeling well. Most competitive runners run during breastfeeding with little perceived impact.