Exposure–outcome relationship between 5-y exposure to (A) road traffic noise and (B) railway noise and risk for stroke in models adjusted for age, sex, calendar year, educational level, marital status, area income, and other noise sources. The vertical whiskers show HRs with 95% CIs positioned at the median of each exposure category, compared with the reference category [see Table S6 for HRs (95% CIs), and numbers of cases]. Note: CI, confidence interval; HR, hazard ratio, , 24-h annual average noise level of road traffic noise.