Byline: Kai Cao, From the Department of Epidemiology and Health Statistics, School of Public Health, Capital Medical University (KC, CW, QL, KY, LT, XG); Beijing Municipal Key Laboratory of Clinical Epidemiology (KC, CW, QL, KY, LT, XG); Beijing Key Laboratory of Environment Toxicology (ML); School of Public Health, Capital Medical University (ML); and Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory (KC), Beijing, China.; Meiling Liu; Chao Wang; Qingrong Liu; Kun Yang; Lixin Tao; Xiuhua Guo Abstract To estimate children's long-term seizure outcomes after hemispheric surgery and the associated predictors.A systematic review of 4 databases and a meta-analysis were performed from January 1, 1995 to August 31, 2015. The databases included PubMed, Embase, Science Direct, and Web of Science; patients were classified into the Engel Class I group and the Engel Class II to IV group, according to their seizure outcomes. Nine potential predictors were then stratified across the groups and estimated using the Wilcoxon rank-sum test for continuous variables and the Chi-squared test for categorical variables.The search yielded 15 retrospective studies, with a total sample size of 380. Five years after surgery, 268 (0.71, 95% confidence interval [CI]: 0.64-0.78) children were seizure free; the seizure onset age in the Engel Class I group was significantly higher than that of the Engel Class II to IV group (standardized mean difference [SMD] = 0.26, 95% CI: 0.03-0.49, P = 0.028); specifically, when predicting the positive long-term outcomes, the odds ratio for late onset age ([greater than or equal] 3.6 months, median value of the Engel Class II-IV group) versus early onset age was 2.65 (95% CI: 1.454-4.836, z = 3.18, P = 0.001). The abnormal magnetic resonance imaging (MRI) findings were more predictive for positive seizure outcomes than the normal findings (odds ratio [OR] = 4.60, 95% CI: 1.27-16.62, P = 0.02).Following hemispheric surgery, the long-term prognosis of children with epilepsy was good. Late seizure onset (ageÇè[greater than or equal] Çè3.6 months) and abnormal MRI findings were positive predictors for long-term seizure control in children.