Role of behavioural and age-related factors in the long-term impact of tooth loss on oral health-related quality of life: A 25-year follow-up of Swedish older adults.

Objectives: The primary aim of this study was to assess any long-term association between tooth loss at age 50 and subsequent impaired oral health-related quality of life, OHRQoL, at age 65, 70 and 75, adjusted for time invariant socio-demographic-and time variant behavioural and age-related factors in terms of disadvantages with functional, social, health and psychological concerns. As a second aim, this study examined whether behavioural- and age-related factors played a role in explaining any long-term association between early tooth loss and subsequent OHRQoL.

Methods: In 1992, 6346 residents, aged 50, consented to participate in a prospective cohort study and 3060 completed postal questionnaire follow-ups every fifth year (six in total) until 2017. Information on tooth loss was assessed at baseline at age 50. Behavioural- and age-related covariates were assessed repeatedly at ages 65, 70 and 75. OHRQoL was the repeated outcome measure assessed by the Oral Impact on Daily Performance, OIDP at age 65, 70 and 75. Generalized Estimating Equations, GEE, with binomial logit function was used to test the association between tooth loss and prevalence of oral impacts (OIDP) adjusting for counfounders and potential mediators. The role of behavioural and age-related factors in explaining the association between early tooth loss and OHRQoL was tested using the change in estimate approach.

Results: Tooth loss and time variant behavioural- and age-related covariates associated independently with higher odds of impaired OHRQoL across time. The long-term impact of tooth loss seemed to be partly explained by time variant covariates related to functional and psychological concerns. Participants who had excessive tooth loss at age 50 were 2.5 times more likely to experience oral impacts before adjustment of covariates. After adjustment of functional- and psychological-covariates, participants were, respectively, 1.6 times and 1.4 times more likely to experience oral impacts.

Conclusion: This study revealed that early tooth loss at age 50 was independently associated with subsequent impaired OHRQoL at ages 65, 70 and 75. The aspects of behavioural- and age-related factors in terms of disadvantages in functional and psychological concerns seemed to play a role in explaining the long-term impact of tooth loss on impaired OHRQoL. A mid-life approach to the prevention of tooth loss for the protection of subsequent adverse health outcomes should guide health promotion interventions and also be recognized by oral health care providers both for patient interaction and clinical decision making.