Objective: To review population-based studies of the prevalence and incidence of epilepsy worldwide and use meta-analytic techniques to explore factors that may explain heterogeneity between estimates. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed. We searched MEDLINE and EMBASE for articles published on the prevalence or incidence of epilepsy since 1985. Abstract, full-text review, and data abstraction were conducted in duplicate. Meta-analyses and meta-regressions were used to explore the association between prevalence or incidence, age group, sex, country level income, and study quality. Results: A total of 222 studies were included (197 on prevalence, 48 on incidence). The point prevalence of active epilepsy was 6.38 per 1,000 persons (95% confidence interval [95% CI] 5.57–7.30), while the lifetime prevalence was 7.60 per 1,000 persons (95% CI 6.17–9.38). The annual cumulative incidence of epilepsy was 67.77 per 100,000 persons (95% CI 56.69–81.03) while the incidence rate was 61.44 per 100,000 person-years (95% CI 50.75–74.38). The prevalence of epilepsy did not differ by age group, sex, or study quality. The active annual period prevalence, lifetime prevalence, and incidence rate of epilepsy were higher in low to middle income countries. Epilepsies of unknown etiology and those with generalized seizures had the highest prevalence. Conclusions: This study provides a comprehensive synthesis of the prevalence and incidence of epilepsy from published international studies and offers insight into factors that contribute to heterogeneity between estimates. Significant gaps (e.g., lack of incidence studies, stratification by age groups) were identified. Standardized reporting of future epidemiologic studies of epilepsy is needed.

Importance: A comprehensive review of the evidence exploring the outcomes of enhanced recovery after surgery (ERAS) guidelines has not been completed.Objective: To evaluate if ERAS guidelines are associated with improved hospital length of stay, hospital readmission, complications, and mortality compared with usual surgical care, and to understand differences in estimates based on study and patient factors.Data Sources: MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Central were searched from inception until June 2021.Study Selection: Titles, abstracts, and full-text articles were screened by 2 independent reviewers. Eligible studies were randomized clinical trials that examined ERAS-guided surgery compared with a control group and reported on at least 1 of the outcomes.Data Extraction and Synthesis: Data were abstracted in duplicate using a standardized data abstraction form. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Risk of bias was assessed in duplicate using the Cochrane Risk of Bias tool. Random-effects meta-analysis was used to pool estimates for each outcome, and meta-regression identified sources of heterogeneity within each outcome.Main Outcome and Measures: The primary outcomes were hospital length of stay, hospital readmission within 30 days of index discharge, 30-day postoperative complications, and 30-day postoperative mortality.Results: Of the 12 047 references identified, 1493 full texts were screened for eligibility, 495 were included in the systematic review, and 74 RCTs with 9076 participants were included in the meta-analysis. Included studies presented data from 21 countries and 9 ERAS-guided surgical procedures with 15 (20.3%) having a low risk of bias. The mean (SD) Reporting on ERAS Compliance, Outcomes, and Elements Research checklist score was 13.5 (2.3). Hospital length of stay decreased by 1.88 days (95% CI, 0.95-2.81 days; I² = 86.5%; P < .001) and the risk of complications decreased (risk ratio, 0.71; 95% CI, 0.59-0.87; I² = 78.6%; P < .001) in the ERAS group. Risk of readmission and mortality were not significant.Conclusions and Relevance: In this meta-analysis, ERAS guidelines were associated with decreased hospital length of stay and complications. Future studies should aim to improve implementation of ERAS and increase the reach of the guidelines.

We thank Zack and Kobau for their interest in our article.1 We agree there is marked heterogeneity among studies and acknowledged this throughout the article. We attempted to mitigate heterogeneity by using a random effects model and reported medians with 25th and 75th percentiles alongside pooled estimates to provide readers with a more complete picture of data distribution and heterogeneity. In the article, we also identified geographic outliers.1 Despite marked heterogeneity, pooled estimates and medians were similar. Together, they provide a valid overview of this literature and were accompanied in the article by appropriately cautionary statements about their interpretation.1 Further, we attempted formal analyses of sources of heterogeneity, which proved difficult and did not yield definitive conclusions, and provided these results in supplementary e-tables.1