Impact of the consumption tax rate increase on out-of-hospital cardiac arrest in Japan: an interrupted time series analysis

OBJECTIVES: The Japanese government increased the consumption tax rate from 5% to 8% on 1 April 2014. The impact of this policy on the incidence of out-of-hospital cardiac arrest (OHCA) is unknown. Thus, we aimed to evaluate a potential association between the consumption tax rate increase and OHCA. DESIGN: An interrupted time series design. SETTING: National registry data for all cases of OHCA in Japan. PARTICIPANTS: All OHCA cases of presumed cardiac origin in Japan between January 2005 and December 2016. PRIMARY OUTCOME MEASURE: We used a quasiexperimental design with interrupted time series analysis to investigate whether the consumption tax rate increase was associated with changes in OHCA trends after adjusting for baseline trends. The effective date of the consumption tax rate increase (1 April 2014) was used to split the OHCA data into categories of before and after the change. RESULTS: In total, 808 055 OHCAs of presumed cardiac origin were reported during the study period. Prior to the consumption tax rate increase, the mean monthly OHCA rate was 5.12 cases per 100 000 population (mean monthly count: 5483.45). After adjusting for underlying trends, there was a substantial step change in the incidence of OHCAs (relative risk (RR): 0.921; 95% CI 0.889 to 0.955). CONCLUSIONS: The implementation of the consumption tax rate increase was associated with a significant decrease in the incidence of OHCAs in Japan.