Effects of being eligible for specific health guidance on health outcomes: A regression discontinuity analysis using Japan's data on specific health checkups

Abstract

The significance of general health checkups and guidance is controversial. To examine the effectiveness of Japan's specific health checkup (SHC) and specific health guidance (SHG) programs, this study applied a regression discontinuity design (RDD) using the SHC results database collected by a private company. We applied a sharp RDD with a cutoff body mass index (BMI) of 25 kg/m2 for those with a waist circumference (WCF) of <85 cm in men and < 90 cm in women, with risks of hypertension, dyslipidemia or diabetes, and aged between 40 and 64 years. Study outcomes were differences in BMI, WCF, and major cardiovascular risk factors between the baseline year and the following year. We analyzed the data of baseline years of 2015, 2016, and 2017 separately and their pooled data. We judged the results to be robust significant when significant results in the same direction were found in all four analyses. A total of 1,041,607 observations out of 614,253 people were analyzed. We found robust significant results that those eligible for SHG in the baseline year had a lower BMI (both men and women) and lower WCF (men only) in the following year than those not eligible for SHG: BMI for men (−0.12 kg/m2, 95% CI [confidence interval]: −0.15 to −0.09); BMI for women (−0.09 kg/m2, 95% CI: −0.13 to −0.06); and WCF for men (−0.36 cm, 95% CI: −0.47 to −0.28) in the pooled data. Robust significant results were not found in WCF for women or in major cardiovascular risk factors.