Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

Redundant publication of systematic reviews and meta-analyses (SRs/MAs) on the same topic presents an increasing burden for clinicians. The aim of this study was to describe variabilities in effect size and methodological quality of overlapping surgery-related SRs/MAs and to investigate factors associated with their postpublication citations. PubMed/MEDLINE was searched to identify SRs/MAs of RCTs on thoracoabdominal surgeries published in 2015. Previous SRs/MAs on the same topics published within the preceding 5 years (2011–2015) were identified and 5-year citation counts (through to 2020) were evaluated. Discrepancies in pooled effect sizes and their methodological quality using A Measurement Tool to Assess Systematic Reviews (AMSTAR) among overlapping SRs/MAs were assessed. The SR/MA-level factors associated with 5-year citation counts were explored, using a mixed-effects regression model with a random intercept for surgical topics. A total of 57 surgery-related SRs/MAs (48 topics) published in 2015 were identified, and 146 SRs/MAs had overlapping publications on 29 topics (60.4 per cent of all topics) in the preceding 5 years. There was considerable variability in methodological quality of SRs/MAs and coverage probability for relevant RCTs, resulting in discrepant effect size estimates for the same topic. High quality (AMSTAR score 8–11) was independently associated with higher 5-year citation counts (coefficient = 32.82; 95 per cent c.i. 15.63 to 50.02; P < 0.001). Overlapping SRs/MAs with high variability in results and methodological quality were common in surgery. A high-quality SR/MA score was an independent predictor of more frequent citations. Researchers and journal editors should concentrate their efforts on limiting publications to higher-quality reviews.

Background: Growing evidence suggests that women born preterm or small have an increased risk of experiencing hypertensive disorders during pregnancy; however, a quantitative summary of the evidence on this issue is unavailable. Objective: We aimed to systematically review the literature to describe the association between being born preterm, low birthweight (LBW), or small for gestational age (SGA), and future gestational hypertension, preeclampsia, or eclampsia. Methods: We searched the MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and ICTRP databases. We included all cohort and case–control studies examining the association between LBW, preterm birth, or SGA and hypertensive disorders in pregnancy. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model. We assessed the certainty of evidence for each outcome using the Grading of Recommendations, Assessment, Development, and Evaluation criteria. Results: Eleven studies were identified, totalling 752 316 participants. Being born preterm, LBW, or SGA was associated with gestational hypertension [pooled odds ratio (OR), 1.31; 95% confidence interval (CI) 1.15–1.50; moderate certainty of evidence] and preeclampsia (pooled OR, 1.35; 95% CI 1.23–1.48; moderate certainty of evidence). No study measured eclampsia as an outcome. Conclusion: Women born preterm, LBW, or SGA have an increased risk of gestational hypertension and preeclampsia. The course of the mother's own birth might be used to identify women at risk of gestational hypertension and preeclampsia.