Association between non-communicable diseases and work productivity and health-related quality of life among Japanese workers: a cross-sectional study using a claims database and survey data
Noriharu Itoh, Yoshiyuki Saito, Yoshimasa Ogata, Yusuke Karasawa, Kazutaka NozawaObjectives
To assess the impact of non-communicable diseases (NCDs) by number and pattern on productivity loss costs (PLCs) and health-related quality of life (HRQoL) in a large working-age population in Japan.
Design
Cross-sectional analysis of linked claims—survey data with sex-stratified multivariable regression.
Setting
Employment-Based Health Insurance Associations in Japan. Administrative claims using International Classification of Diseases, Tenth Revision codes were linked to an online questionnaire (November 2022).
Participants
Insured workers and families aged 18–65 years who completed the survey (n=18 236; mean age 48.7 years; 66.2% men).
Primary and secondary outcome measures
Primary: PLC, estimated from the Work Productivity and Activity Impairment instrument using the Human Capital Method (annual US$).
Secondary
HRQoL measured using the EuroQoL 5-Dimension 5-Level index. Exposures were NCD categories, multimorbidity counts and high-impact disease combinations. Models adjusted for sex, age and the number of other conditions.
Results
Multimorbidity (≥2 conditions) was present in 58.4% (56.3% men; 62.5% women); 29.3% had ≥5 conditions. Women had higher NCD prevalence (76.9% vs 70.0%), higher median PLC (US$3683 vs US$117) and lower median HRQoL (0.89 vs 1.00) than men. In adjusted analyses, neuropsychiatric conditions were associated with higher PLC in both sexes (men: US$2393 (95% CI 1966 to 2820); women: US$2097 (US$1442 to US$2751)). Musculoskeletal disorders were statistically significant in men but not in women (US$809 (US$381 to US$1236)), whereas genitourinary disorders were statistically significant in women but not in men (US$701 (US$121 to US$1282)). Neuropsychiatric disorders were associated with lower HRQoL in both sexes (men: −0.040 (−0.045 to −0.034); women: −0.044 (−0.053 to −0.035)); musculoskeletal disorders showed similar decrements (men: −0.031 (−0.037 to −0.025); women: −0.040 (−0.049 to −0.031)). Combinations involving sleep and neuropsychiatric disorders produced the highest PLC (eg, depressive episode and sleep disorder: men: US$5219.9 (US$3646.4 to US$6793.4); women: US$5858.5 (US$2634.4 to US$9082.5)). Each additional condition was independently associated with higher PLC and lower HRQoL.
Conclusions
In this cross-sectional study of Japanese workers, specific combinations of chronic conditions, particularly neuropsychiatric conditions co-occurring with sleep disorders and musculoskeletal disorders, were associated with greater productivity loss and lower HRQoL than predicted by the number of co-occurring diseases alone. These findings suggest that workplace health strategies addressing high-impact disease combinations may warrant further investigation in longitudinal studies.