Browsing by Subject "risk"

Now showing 1 - 4 of 4
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    ItemOpen Access
    Are prediction models for vaginal birth after cesarean accurate?
    (American journal of obstetrics and gynecology, 2019-05) Harris, Benjamin S; Heine, R Phillips; Park, Jinyoung; Faurot, Keturah R; Hopkins, Maeve K; Rivara, Andrew J; Kemeny, Hanna R; Grotegut, Chad A; Jelovsek, J Eric
    BACKGROUND:The use of trial of labor after cesarean delivery calculators in the prediction of successful vaginal birth after cesarean delivery gives physicians an evidence-based tool to assist with patient counseling and risk stratification. Before deployment of prediction models for routine care at an institutional level, it is recommended to test their performance initially in the institution's target population. This allows the institution to understand not only the overall accuracy of the model for the intended population but also to comprehend where the accuracy of the model is most limited when predicting across the range of predictions (calibration). OBJECTIVE:The purpose of this study was to compare 3 models that predict successful vaginal birth after cesarean delivery with the use of a single tertiary referral cohort before continuous model deployment in the electronic medical record. STUDY DESIGN:All cesarean births for failed trial of labor after cesarean delivery and successful vaginal birth after cesarean delivery at an academic health system between May 2013 and March 2016 were reviewed. Women with a history of 1 previous cesarean birth who underwent a trial of labor with a term (≥37 weeks gestation), cephalic, and singleton gestation were included. Women with antepartum intrauterine fetal death or fetal anomalies were excluded. The probability of successful vaginal birth after cesarean delivery was calculated with the use of 3 prediction models: Grobman 2007, Grobman 2009, and Metz 2013 and compared with actual vaginal birth after cesarean delivery success. Each model's performance was measured with the use of concordance indices, Brier scores, and calibration plots. Decision curve analysis identified the range of threshold probabilities for which the best prediction model would be of clinical value. RESULTS:Four hundred four women met the eligibility criteria. The observed rate of successful vaginal birth after cesarean delivery was 75% (305/404). Concordance indices were 0.717 (95% confidence interval, 0.659-0.778), 0.703 (95% confidence interval, 0.647-0.758), and 0.727 (95% confidence interval, 0.669-0.779), respectively. Brier scores were 0.172, 0.205, and 0.179, respectively. Calibration demonstrated that Grobman 2007 and Metz vaginal birth after cesarean delivery models were most accurate when predicted probabilities were >60% and were beneficial for counseling women who did not desire to have vaginal birth after cesarean delivery but had a predicted success rates of 60-90%. The models underpredicted actual probabilities when predicting success at <60%. The Grobman 2007 and Metz vaginal birth after cesarean delivery models provided greatest net benefit between threshold probabilities of 60-90% but did not provide a net benefit with lower predicted probabilities of success compared with a strategy of recommending vaginal birth after cesarean delivery for all women . CONCLUSION:When 3 commonly used vaginal birth after cesarean delivery prediction models are compared in the same population, there are differences in performance that may affect an institution's choice of which model to use.
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    Frequency of Occult High-Grade Squamous Intraepithelial Neoplasia and Invasive Cancer within Anal Condylomata in Men Who Have Sex with Men
    (2010) Schlecht, Hans P; Fugelso, Dana K; Murphy, Ryan K; Wagner, Katiri T; Doweiko, John P; Proper, JoAnn; Dezube, Bruce J; Panther, Lori A
    Human papillomavirus causes anal condylomata, high-grade anal intraepithelial neoplasia, and anal squamous cell cancer. We found high-grade intraepithelial neoplasia or squamous cell cancer in 75 (47%) of 159 HIV-seropositive men who have sex with men (MSM) and in 42 (26%) of 160 HIV-seronegative MSM with anal condylomata meriting surgery (P < .001, determined by use of the X-2 test). Anal condylomata in MSM often harbor high-grade intraepithelial neoplasia and squamous cell cancer.
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    Optimal Critical Values for Pre-Testing in Regression
    (1976) Toyoda, T; Wallace, TD
    In this paper we derive and present optimal critical points for pre-tests in regression using a minimum average relative risk criterion. We use the same type risk functions as Sawa and Hiromatsu [8] who, in a recent paper in this journal, derived pre-test critical values using a minimax regret criterion. Since James-Stein type estimators can be shown to dominate any pre-test estimator for the risk functions used here and in [8], no normative claims are made for the critical values we give. However, the use of pre-testing procedures continues in practice and the results given here, contrasted with other results, add to information about the character of costs and returns to such practices.
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    The association between cognitive function and subsequent depression: a systematic review and meta-analysis.
    (Psychol Med, 2017-01) Scult, MA; Paulli, AR; Mazure, ES; Moffitt, TE; Hariri, AR; Strauman, TJ
    Despite a growing interest in understanding the cognitive deficits associated with major depressive disorder (MDD), it is largely unknown whether such deficits exist before disorder onset or how they might influence the severity of subsequent illness. The purpose of the present study was to conduct a systematic review and meta-analysis of longitudinal datasets to determine whether cognitive function acts as a predictor of later MDD diagnosis or change in depression symptoms. Eligible studies included longitudinal designs with baseline measures of cognitive functioning, and later unipolar MDD diagnosis or symptom assessment. The systematic review identified 29 publications, representing 34 unique samples, and 121 749 participants, that met the inclusion/exclusion criteria. Quantitative meta-analysis demonstrated that higher cognitive function was associated with decreased levels of subsequent depression (r = -0.088, 95% confidence interval. -0.121 to -0.054, p < 0.001). However, sensitivity analyses revealed that this association is likely driven by concurrent depression symptoms at the time of cognitive assessment. Our review and meta-analysis indicate that the association between lower cognitive function and later depression is confounded by the presence of contemporaneous depression symptoms at the time of cognitive assessment. Thus, cognitive deficits predicting MDD likely represent deleterious effects of subclinical depression symptoms on performance rather than premorbid risk factors for disorder.