Determinants of change in oral health-related quality of life over 7 years among older Japanese.

Because there are more elderly people than ever before and because they are living for longer periods of time, it is essential to understand the determinants of healthy ageing. This study examined changes in oral health-related quality of life (OHRQoL) among Japanese elderly over a 7-year period. A sample of independently living individuals (aged 60+ years) underwent a questionnaire and dental examination at baseline and 7 years afterwards. The Geriatric Oral Health Assessment Index (GOHAI) was used to assess the impact of oral conditions. Occlusal force and salivary flow were also assessed. Of the 411 participants assessed at baseline, 130 (31·6%) accepted to participate after 7 years. There were no significant differences between those lost to follow-up and those assessed at 7 years, except that a higher proportion of the latter rated their baseline general health as good. Among the latter, the overall mean GOHAI score did not change significantly (11·8 at baseline and 11·1 at follow-up; P = 0·16). However, after controlling for age, gender and baseline GOHAI score, participants who had lost teeth or experienced a decline in occlusal force after 7 years had higher follow-up GOHAI scores (indicating poorer OHRQoL). Unfavourable changes in clinical oral status over time are reflected in poorer self-rated oral health.