Association between accessibility to emergency cardiovascular centers and cardiovascular mortality in Japan

Abstract

Objective: The aim of this study was to examine the association between accessibility to cardiovascular emergency centers and cardiovascular mortality in Japan. Design: A semi-ecological study. Setting: Three databases were generated: accessibility to emergency cardiovascular centers, population records and death records. Main Outcome Measures: The standardized mortality ratio (SMR) for cardiovascular disease was adjusted by age and sex. Accessibility was represented by transfer time, number of cardiovascular emergency hospitals, and the proportion of habitable areas. Combinations of the three were divided into Categories 1-8 from the worst to the best, and the association with SMR was analyzed. Results: There were 1998 cardiovascular emergency hospitals. The median of crude mortality was 0.16%. The median SMR of the reference Category 8 (transfer time <30 min and habitable area ≥50% with cardiovascular emergency hospitals) was 0.96, but that of the low accessibility Category 1 (transfer time ≥30 min and habitable area <50% without cardiovascular emergency hospitals) was 1.10. The SMR of accessibility Category 1: Category 8 was 1.18 (95% confidence interval: 1.14-1.21). Conclusions: Decreased accessibility to cardiovascular emergency hospitals was associated with increased SMR. Areas with less accessibility and higher cardiovascular mortality were characterized by geographical variability in Japan.