Oral health-related quality of life outcomes in a randomized clinical trial to assess a community-based oral hygiene intervention among adults living in low-income senior housing

Background Quality of life outcomes have been used frequently in clinical trials of oral health interventions. This study assessed the effects of a randomized trial on oral health related quality of life comparing an individual-based oral hygiene intervention to a community-based intervention. Methods Participants were recruited from six low-income senior housing residences. Buildings were randomly assigned to receive the individual-based intervention followed by the community-based intervention or to receive the community-based intervention followed by the individual intervention. Participants’ oral hygiene was assessed at baseline (T0), one month after the first intervention (T1) and one month after the second intervention (T2) and six months after the T2 assessment (T3). Oral hygiene was measured by the Gingival Index (GI) and Plaque scores (PS). Surveys collected data on beliefs, attitudes, behaviors and self-reported health status at T0, T1 and T2. Only oral hygiene and quality of life, measured by the General Oral Health Assessment Index (GOHAI), was assessed at all time points. general linear mixed models (GLMM) were used to assess changes in GOHAI over time, the interaction of condition by time and the contribution of psychosocial, behavioral, health status and background variables to changes in GOHAI. Results 331 people completed T0 assessments; 306 completed T1; 285 completed T2 and 268 completed T3. Scores on GOHAI at T0 ranged from 10 to 48 with a mean of 39.7 (sd = 7.8) and a median of 42. At T1, mean GOHAI was 40.7 (sd = 8.2), at T2 mean GOHAI was 41.1 (sd = 7.8) and at T3, GOHAI was 42.3 (sd = 8.2). GLMM showed that GOHAI improved significantly from T0 to T3 (p = 0.01) but the time by intervention interaction was not significant indicating that both interventions were effective in improving GOHAI but one intervention was not better than the other. Ethnicity, health status, worries, self-efficacy, number of missing teeth and symptoms of dry mouth were related to improvements in GOHAI. Neither GI nor PS were related to GOHAI. Conclusions The participants reported relatively good oral health related quality of life which improved significantly over time. Improvement occurred among all participants regardless of condition, suggesting that either intervention would be effective in future studies. Trial Registry: Clinicaltrials.gov, Clinical Trials ID #NCT02419144; Title: A Bi-level Intervention to Improve Older Adult Oral Health Status; Registered 04/07/2015 URL: https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0005H9X&selectaction=Edit&uid=U0000KBK&ts=2&cx=-rajj5q