title: Participation in health check-ups and mortality using propensity score matched cohort analyses.
abstract: OBJECTIVE
  All Japanese aged ≥40 years are eligible for free annual health check-ups including blood pressure and cholesterol measurements. It is well known that health check-up screenees are more likely to have healthy lifestyles and better health conditions than non-screenees. Therefore, controlling these factors is required to investigate whether screenees have a lower mortality risk than non-screenees independent of their lifestyles or health conditions.
  
  
  METHODS
  We followed 48,775 Japanese National Health Insurance beneficiaries aged 40-79 years since 1994 for 11 years. We used Cox proportional hazard models adjusted for possible confounding factors. We also performed propensity for use of the health check-up matched cohort analyses.
  
  
  RESULTS
  Compared to non-screenees, multiple-adjusted hazard ratios (95% confidence intervals) for all-cause and cardiovascular disease mortality among screenees were 0.74 (0.62-0.88) and 0.65 (0.44-0.95) for men and 0.69 (0.52-0.91) and 0.61 (0.36-1.04) for women, respectively. These relations were also observed when we used propensity matched cohort analyses.
  
  
  CONCLUSIONS
  This is the first study to show that mortality rates are lower among screenees than non-screenees in Japanese health check-ups when propensity matched cohort analyses were used for adjusting confounding factors. Further prospective studies, including randomized controlled trials, are required to confirm whether screening lowers mortality.
authors.affiliation: Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan. hozawa-thk@umin.ac.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hozawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kuriyama
authors.forename: Ikue
authors.initials: I
authors.lastname: Watanabe
authors.forename: Masako
authors.initials: M
authors.lastname: Kakizaki
authors.forename: Kaori
authors.initials: K
authors.lastname: Ohmori-Matsuda
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Sone
authors.forename: Masato
authors.initials: M
authors.lastname: Nagai
authors.forename: Yumi
authors.initials: Y
authors.lastname: Sugawara
authors.forename: Akemi
authors.initials: A
authors.lastname: Nitta
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.forename: Ichiro
authors.initials: I
authors.lastname: Tsuji
mesh_terms: D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends*; D010349:Patient Compliance / Q000706:statistics & numerical data*; D010808:Physical Examination / Q000706:statistics & numerical data*; D057216:Propensity Score; D016016:Proportional Hazards Models