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Welcome to the Systematic Review Data Repository
The Systematic Review Data Repository (SRDR) is a powerful and easy-to-use tool for the extraction and management of data for systematic review or meta-analysis. It is also an open and searchable archive of systematic reviews and their data.
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Recently Completed and Deposited Reports Data

Phenotypes and body mass in women with PCOS identified in Referral vs. Unselected populations: systematic review and meta-analysis


Public Report Complete
Statistics: 43 Studies, 2 Key Questions, 1 Extraction Form,
Date Created: Jan 23, 2015 09:08PM
Description: Objective: To compare the prevalence of PCOS phenotypes and obesity of PCOS women seen in the clinical (referred) setting vs. those identified in general population.

SRDR Project Indexing


Public Report Complete
Statistics: 143 Studies, 1 Key Question, 1 Extraction Form,
Date Created: May 20, 2018 11:24PM
Description: This is a Methods Research project that catalogs the various projects with publicly available data on the SRDR Webpage.

Screening for Elevated Blood Lead Levels in Childhood [Entered Retrospectively]


Public Report Complete
Statistics: 25 Studies, 6 Key Questions, 1 Extraction Form,
Date Created: Jul 09, 2019 04:09PM
Description: Background: In 2006, the United States Preventive Services Task Force (USPSTF) found insufficient evidence to recommend for or against routine screening for elevated blood lead levels in asymptomatic children aged 1 to 5 who are at increased risk for lead poisoning (I recommendation), and recommended against routine screening for those at average risk (D recommendation). Purpose: To synthesize evidence on the effects of screening, testing, and treatment for elevated blood lead level in children aged five and under in the primary care setting, in order to update a prior USPSTF review on screening for elevated blood lead levels in childhood. Data Sources: Cochrane CENTRAL and Cochrane Database of Systematic Reviews (through June 2018), and Ovid MEDLINE (1946 to June 2018), reference lists, and surveillance through December 5, 2018. Study Selection: English-language trials and observational studies of screening effectiveness, test accuracy, benefits and harms of screening and interventions in asymptomatic children five and under. Data Extraction: One investigator abstracted details about study design, patient population, setting, screening method, follow up, and results. Two investigators independently applied pre specified criteria to rate study quality using methods developed by the USPSTF. Discrepancies were resolved through consensus. Data Synthesis (Results): A total of 22 studies were included in this review (N=10,449). No studies directly evaluated clinical benefits or harms of screening versus not screening children for elevated blood lead levels. More than one positive answer on the 5-item 1991 Centers for Disease Control and Prevention (CDC) screening questionnaire was associated with a pooled sensitivity of 48 percent (95% confidence interval [CI], 31.4 to 65.6%) and specificity of 58 percent (95% CI, 39.9 to 74.0%) for identifying children with a venous blood level >10µg/dL (5 studies, N = 2,265). Adapted versions of the CDC questionnaire did not demonstrate improved accuracy. Capillary blood lead testing demonstrated sensitivity of 87 percent to 91 percent and specificity >90 percent, compared with venous measurement (4 studies, N = 1,431). Counseling and nutritional interventions or residential lead hazard control techniques did not reduce blood lead concentrations in asymptomatic children, but studies were few and had methodological limitations (7 studies, N = 1,419). A trial of dimercaptosuccinic acid (DMSA) chelation therapy found reduced blood lead levels in children at one week to one year but not at 4.5 to 6 years (N = 780), while another trial found no effect at one- and six-months (N = 39). Seven-year followup assessments showed no effect on neuropsychological development; a small deficit in linear growth (height difference at 7 years in treated patients 1.17cm; 95% CI, 0.41 to 1.93); and poorer cognitive outcomes reported as the Attention and Executive Functions sub-score of the Developmental Neuropsychological Assessment (NEPSY) (unadjusted difference -1.8; 95% CI, -4.5 to 1.0, adjusted P = 0.045) in children treated with DMSA chelation. Limitations: Limited to English-language articles; quality and applicability of studies were limited due to study design, poor reporting of statistical outcomes, and loss to follow up. Studies were lacking on the effectiveness of screening or effectiveness of treatments in reducing elevated blood lead levels or improving health outcomes in children. There was no direct evidence on the harms of screening children for elevated blood lead levels. Conclusions: Evidence on the benefits and harms of screening children for elevated lead levels is lacking. Screening questionnaires are not accurate for identifying children with elevated blood lead levels. Capillary blood testing is slightly less accurate than venous blood levels for identification of elevated blood levels. Treatment studies of chelating agents, often combined with environmental or household interventions, were not associated with sustained effects on blood level levels but were associated with harms.

Screening for HIV Infection in Asymptomatic, Nonpregnant Adolescents and Adults [Entered Retrospectively]


Public Report Complete
Statistics: 29 Studies, 5 Key Questions, 1 Extraction Form,
Date Created: Jul 11, 2019 07:26PM
Description: Background: A 2012 systematic review on HIV screening for the U.S. Preventive Services Task Force (USPSTF) found strong evidence that antiretroviral therapy (ART) is associated with improved clinical outcomes in persons with CD4+ T helper cell (CD4) counts less than 500 cells/mm3 and substantially decreases risk of HIV transmission, with certain antiretroviral agents potentially associated with long-term cardiovascular harms. The USPSTF previously found HIV screening tests to be highly accurate. Purpose: To systematically update the 2012 USPSTF review on screening for HIV in adolescents and adults, focusing on research gaps identified in the prior review. Data Sources: We searched the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and MEDLINE (2012 to June 2018) and manually reviewed reference lists, with surveillance through January 2019. Study Selection: Randomized, controlled trials (RCTs) and controlled observational studies on benefits and harms of screening versus no screening and on the yield of screening at different intervals; the effects of earlier versus later initiation of ART; and long-term (≥2 years) harms of ART. Data Extraction: One investigator abstracted data and a second investigator checked data abstraction for accuracy. Two investigators independently assessed study quality using methods developed by the USPSTF. Data Synthesis (Results): We did not identify any studies on benefits or harms of HIV screening versus no screening, or on the yield of repeat versus one-time screening or of screening at different intervals. Two new RCTs conducted completely or partially in low-resource settings found initiation of ART in persons with CD4 counts greater than 500 cells/mm3 associated with lower risk of composite clinical outcomes (mortality, AIDS-defining events, or serious non-AIDS events) (relative risk [RR], 0.44 [95% confidence interval (CI), 0.31 to 0.63] and RR, 0.57 [95% CI, 0.35 to 0.95]); early initiation of ART was not associated with increased risk of cardiovascular events. A large observational study also found initiation of ART in persons in high-resource settings with CD4 counts greater than 500 cells/mm3 to be associated with reduced risk of mortality or AIDS events, although the magnitude of effect was smaller. New evidence regarding the association between abacavir use and increased risk of cardiovascular events was inconsistent, and certain antiretroviral regimens were associated with increased risk of long-term neuropsychiatric, renal, hepatic, and bone adverse events. Limitations: Only English-language articles were included. Observational studies were included. Studies conducted in resource-poor settings were included, which might limit applicability to general screening in the United States. Conclusions: New evidence extends effectiveness of ART to asymptomatic persons with CD4 counts greater than 500 cells/mm3. Certain ART regimens may be associated with long-term cardiovascular, neuropsychiatric, hepatic, renal, or bone harms, but early initiation of ART is not associated with increased risk of cardiovascular events. Research is needed to inform optimal screening intervals.

Screening for HIV Infection in Pregnant Women [Entered Retrospectively]


Public Report Complete
Statistics: 36 Studies, 5 Key Questions, 1 Extraction Form,
Date Created: Jul 11, 2019 07:22PM
Description: Structured Abstract Background: A 2012 systematic review on HIV screening for the U.S. Preventive Services Task Force (USPSTF) found strong evidence that antiretroviral therapy (ART) greatly decreases the risk of mother-to-child HIV transmission but that use of ART may be associated with increased risk of preterm delivery. The USPSTF previously found HIV screening tests to be highly accurate. Purpose: To systematically update the 2012 USPSTF review on HIV screening in pregnancy, focusing on research gaps identified in the prior review. Data Sources: We searched the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and MEDLINE (2012 to June 2018) and manually reviewed reference lists, with surveillance through January 25, 2019. Study Selection: We selected randomized, controlled trials (RCTs) and cohort studies of pregnant women that reported risk of mother-to-child transmission or maternal or infant harms associated with prenatal HIV screening or ART during pregnancy. Data Extraction: One investigator abstracted data and a second investigator checked data abstraction for accuracy. Two investigators independently assessed study quality using methods developed by the USPSTF. Data Synthesis (Results): We identified no studies on the benefits or harms of prenatal HIV screening versus no screening, or on the yield of repeat versus one-time screening or screening at different intervals. One new RCT and five new cohort studies were consistent with the 2012 USPSTF review in finding combination ART highly effective at reducing the risk of mother-to-child transmission of HIV infection, especially if started early in pregnancy (rate of mother-to-child transmission <1%). As in the prior USPSTF review, one new RCT and several observational studies found certain ART regimens associated with increased risk of preterm delivery without increased risk of low birth weight. One RCT conducted in Africa found prenatal tenofovir-based ART associated with very preterm delivery and early infant death versus zidovudine-based ART, but the trial had methodological limitations. Prenatal exposure to most currently recommended ART drugs was not associated with increased risk of overall birth defects, but limited evidence found certain ART agents and regimens associated with increased risk of congenital abnormalities, cardiac anomalies, and echocardiographic changes, with no association with adverse neurodevelopmental outcomes. Evidence on long-term maternal harms associated with short-term exposure to ART during pregnancy remains limited, with some evidence of short-term harms. Limitations: Only English-language articles were included. Observational studies were included. Studies conducted in resource-poor settings were included, which might limit applicability to screening in the United States. Conclusions: Combination ART is highly effective at reducing risk of mother-to-child HIV transmission. The USPSTF previously determined that avoidance of breastfeeding and Caesarean delivery in women with HIV ribonucleic acid levels greater than 1,000 copies/mL near the time of delivery is also effective at reducing mother-to-child transmission, and that prenatal screening is accurate at diagnosing HIV infection. Use of certain ART regimens during pregnancy is associated with increased risk of preterm delivery and may be associated with other adverse pregnancy outcomes. Although more evidence is required to better understand short- and long-term maternal and infant harms, selection of ART regimens may help mitigate or reduce harms.

Pre-Exposure Prophylaxis for the Prevention of HIV Infection [Entered Retrospectively]


Public Report Complete
Statistics: 52 Studies, 5 Key Questions, 1 Extraction Form,
Date Created: Jul 11, 2019 07:14PM
Description: Background: Effective prevention strategies for HIV infection are an important public health priority. Pre-exposure prophylaxis (PrEP) involves use of antiretroviral therapy (ART) regularly (e.g., daily) or before and after HIV exposure events to decrease the risk of acquiring HIV infection. Purpose: To synthesize evidence for the U.S. Preventive Services Task Force (USPSTF) on effects of PrEP on risk of HIV acquisition, mortality, harms, and other clinical outcomes; effects of adherence on PrEP-associated outcomes; and accuracy of methods for identifying potential candidates for PrEP. Data Sources: We searched the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, MEDLINE, and Embase from inception to June 2018 and manually reviewed reference lists; additional surveillance for new literature was conducted through January 25, 2019. Study Selection: Randomized, controlled trials on the benefits and harms of PrEP versus placebo or no PrEP in adults without HIV infection at high risk of becoming infected; studies on the diagnostic accuracy of instruments for predicting incident HIV infection; studies on effects of adherence to PrEP on risk of HIV infection; and studies on rates of adherence to PrEP in U.S. populations. Data Extraction: One investigator abstracted data and a second investigator checked data abstraction for accuracy. Two investigators independently assessed study quality using methods developed by the USPSTF. Data Synthesis (Results): In populations at higher risk of acquiring HIV infection, PrEP was associated with decreased risk of HIV infection versus placebo or no PrEP (11 trials; relative risk [RR], 0.46 [95% confidence interval (CI), 0.33 to 0.66; I2=67%; absolute risk reduction, -2.0% [95% CI, -2.8% to -1.2%] after 4 months to 4 years). Effects were consistent across HIV risk categories and for PrEP with tenofovir disoproxil fumarate plus emtricitabine or tenofovir alone. There was a strong association between higher adherence and greater efficacy (adherence ≥70%: 6 trials; RR, 0.27 [95% CI, 0.19 to 0.39]; I2=0%; adherence >40% to <70%: 3 trials; RR, 0.51 [95% CI, 0.38 to 0.70]; I2=0%; and adherence ≤40%: 2 trials; RR, 0.93 [95% CI, 0.72 to 1.20]; I2=0%; p<0.00001 for interaction). No trial reported effects of nondaily dosing except for one trial of event-driven PrEP (RR, 0.14 [95% CI, 0.03 to 0.63]). There was no difference between PrEP and placebo or no PrEP in risk of serious adverse events (12 trials; RR, 0.93 [95% CI, 0.77 to 1.12]; I2=56%). PrEP was associated with increased risk of renal adverse events (12 trials; RR, 1.43 [95% CI, 1.18 to 1.75]; I2=0%; absolute risk difference, 0.56% [95% CI, 0.09% to 1.04%]) and gastrointestinal adverse events (12 trials; RR, 1.63 [95% CI, 1.26 to 2.11]; I2=43%; absolute risk difference, 1.95% [95% CI, 0.48% to 3.43%]); most adverse events were mild and resolved with discontinuation of PrEP or with longer therapy. The association between PrEP and fracture was not statistically significant (7 trials; RR, 1.23 [95% CI, 0.97 to 1.56]; I2=0%). There were no differences between PrEP and placebo in risk of sexually transmitted infections, but most trials were blinded. Among women who became pregnant in trials of PrEP, PrEP was not associated with increased risk of spontaneous abortion (3 trials; RR, 1.09 [95% CI, 0.79 to 1.50]; I2=0%) or other adverse pregnancy outcomes. Instruments for predicting risk of incident HIV infection had moderate discrimination and require further validation. Adherence to PrEP in U.S. populations of men who have sex with men varied from high to low. Limitations: Restricted to English language, statistical heterogeneity in some pooled analyses, most randomized trials were conducted in low-income settings, limited evidence on adherence in U.S. populations, and evidence lacking in adolescents and pregnant women. Conclusions: In adults at increased risk of HIV infection, oral PrEP with tenofovir or tenofovir disoproxil fumarate plus emtricitabine is associated with decreased risk of HIV infection compared with placebo or no PrEP, although effectiveness decreases with inadequate adherence. PrEP is associated with increased risk of renal and gastrointestinal adverse events. Evidence on the accuracy of instruments for identifying persons at high risk of HIV infection is limited, with further validation needed.



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The data contained in this project are distributed under the terms of the Creative Commons Attribution-NonCommerical license, which permits the use, dissemination, and reproduction in any medium, provided the original work is properly cited, and that the use is non-commercial and otherwise in compliance with the license. See: https://creativecommons.org/licenses/by-nc/3.0/

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