Risk Factors Associated With Early vs Delayed Dementia After Intracerebral Hemorrhage

IMPORTANCE: Patients who have experienced intracerebral hemorrhage (ICH) appear to develop cognitive impairment at high rates, both early after ICH and over the long term. OBJECTIVE: To identify and compare risk factors for early and delayed dementia after ICH. DESIGN, SETTING, AND PARTICIPANTS: A longitudinal study enrolled patients who had experienced ICH from January 1, 2006, to December 31, 2013. A total of 738 participants 18 years or older, without pre-ICH dementia, who presented to a tertiary care academic institution with primary ICH were included in the analyses of early post-ICH dementia (EPID). After accounting for incident dementia and mortality at 6 months, 435 participants were included in the analyses of delayed post-ICH dementia (DPID). EXPOSURES: Intracerebral hemorrhage. MAIN OUTCOMES AND MEASURES: Cognitive performance was captured using the modified Telephone Interview for Cognitive Status test. Outcomes included EPID, diagnosed within 6 months after ICH, and DPID, diagnosed beyond 6 months after ICH. RESULTS: Among 738 patients who had experienced ICH (mean [SD] age, 74.3 [12.1] years; 384 men [52.0%]), 140 (19.0%) developed dementia within 6 months. A total of 435 patients without dementia at 6 months were followed up longitudinally (median follow-up, 47.4 months; interquartile range, 43.4-52.1 months), with an estimated yearly incidence of dementia of 5.8% (95% CI, 5.1%-7.0%). Larger hematoma size (hazard ratio [HR], 1.47 per 10-mL increase; 95% CI, 1.09-1.97; P