BACKGROUND: Working at old ages is regarded as a good way to keep one's health according to the idea of productive aging. However, there is not enough evidence yet whether retirement is good or bad, or the kind of effects it has on the health of older adults aged 65 and over. We examined it by using a recent data of Wako city, a suburb area near Tokyo in Japan. METHODS: One thousand seven hundred sixty-eight participants answered to 3 waves of survey questionnaires: 2008, 2010, and 2012, successively. We considered 3 indicators of health; self-rated health, mental health (GDS15) and HLFC (Higher-Level Functional Capacity: TMIG-IC). In cross-sectional analysis, we compared these 3 indicators by three groups: full-time worker, part-time worker, and non-worker. In longitudinal analysis, we compared these three indicators by two groups: subjects who successively worked in 2008, 2010, 2012, and subjects who worked in 2008 but retired before 2010. We used one-way and two way repeated measures ANCOVA for these analyses, respectively. RESULTS: It was significantly clear that retirement worsened both mental health and HLFC in people aged 65 years and over; especially, mental health worsened rapidly and HLFC gradually. However, these indicators didn't worsen in subjects who changed from full-time jobs to part-time jobs. Quitting from part-time jobs deteriorated mental health gradually and HLFC moderately compared to full-time jobs. CONCLUSION: The results support the activity theory that older adults who quit from full-time jobs deteriorated both mental health and HLFC, though at different speeds. If they make a transit to part-time jobs, the deterioration would be moderate. It shows that working is an effective way of social participation for older people aged 65 years and over in Japan.
