APOE and dementia: These associations remained after additional adjustment for comorbidities and apnea-hypopnea index scores (HR, 1.31 [95% CI, 1.14-1.50]; P < .001) and apolipoprotein E ε4 (HR, 1.22 [95% CI, 1.02-1.45]; P = .03), and they were consistent across sex and age groups.<h4>Conclusions and relevance</h4>In this IPD meta-analysis, a higher sleep EEG-based BAI was associated with a higher risk of incident dementia.