Influences on change in oral health-related quality of life

Background: Studies suggest that people with poor baseline self-rated dental health, or treatment need, have scope for improvement in their self-rated oral health. Objective: To test whether routine dental attendance improved the oral health-related quality of life (OHRQoL) of survey participants and whether change in OHRQoL is influenced by poor baseline OHRQoL or treatment need. Methods: An observational prospective cohort study of a representative sample of Tasmanian adults aged 15 years or more was used. A service use log book and 12 month follow-up mail self-complete questionnaires were added to the Tasmanian component of the Australian National Survey of Adult Oral Health 2004/06. The dependent variable was change in the Oral Health Impact Profile (OHIP–14) severity. The independent variable was dental attendance between baseline and follow-up. The main covariables were baseline OHIP–14 severity and self-reported treatment need. Results: Of the 1,745 in-scope households, 59.7% responded to the telephone interview, of whom 56.1% (409) completed the baseline questionnaires, and 73.5% of those completed the follow-up questionnaires. Survey participants with a low baseline OHIP–14 severity score sufferred a mean increase in OHIP–14 severity (1.07; 95%CI=0.44,1.70), while subjects with high baseline OHIP–14 severity score had a mean decrease in OHIP–14 severity (-2.16; -3.20,-1.12). Baseline treatment need was not associated with change in OHRQoL (p=0.84). In multivariate analysis, poor baseline OHIP–14 severity was associated with a decrease in OHIP-14 severity (Beta=-3.84, p<0.01), while having difficulty in paying a $100 dental bill (2.34, p<0.01) and dental attendance (1.23, p=0.01) were associated with an increase in OHIP-14 severity. Most of the explained variability in OHIP–14 severity came about due to the addition of baseline OHIP–14 severity into the model. Conclusion: Dental attendance and difficulty paying a $100 dental bill were significantly associated with a worsening OHRQoL and poor baseline OHRQoL with an improvement in OHRQoL.