Abstract
Background: In Japan, so-called “specific health checkups” combined with “specific health guidance” have been carried out since 2008. Under this checkup and guidance system, “aggressive health guidance” is provided to people at high risk of metabolic syndrome. To the best of our knowledge, the effects of being notified of eligibility for “aggressive health guidance” on cardiovascular diseases risk factors have not been rigorously examined.
Method: According to the criteria for the “specific health guidance”, men younger than 65 years old with a waist circumference of less than 85 cm and having all of hypertension, dyslipidemia, and diabetes （two or all for smokers） are subject to either one of the following two measures after completing their “specific health checkup”. If their BMI （Body Mass Index） is 25 points or greater, they are notified of their eligibility for “aggressive health guidance.” If their BMI is less than 25, they only receive their health information. Focusing on this differential treatment according to BMI, using regression discontinuity design （RDD）, which is a method of determining the causal relationship from observational data, we examined the effects of being notified of eligibility for “aggressive health guidance.” BMI of 25 points at baseline was used as the cutoff. We used the data of a health insurance society from 2013 to 2015. Outcome variables are 10-year cardiovascular disease risk, waist circumference, BMI, systolic blood pressure, HbA1c, LDL-C, and HDL-C. 1,318 “specific health checkup” participants who met the criteria for the RDD analyses in baseline year（ 2013） were subject to the analyses. Outcome variables are those of 2014 and 2015.
Results: There were no significant differences between those who were notified of eligibility for “aggressive health guidance” and those who were not in any of the outcome variables except for HDL-C in 2014. Although HDL-C of those who were notified of the eligibility was significantly lower than that of those who were not in 2014, placebo tests showed that this was already the case in baseline year. Thus, we could not determine that the significant difference of HDL-C in 2014 was due to the notification of the eligibility for “aggressive health guidance”.
Limitation: Generalization of the results of this study is difficult because samples are limited to male members of a health insurance society, analyses were performed only in a very limited range, and the number of samples is extremely small.
