Population-based changes in oral health-related quality of life in Australia

Good oral health is crucial for overall well-being; yet many people experience pain, discomfort, or social difficulties due to oral problems. Understanding how Australians' oral health and quality of life have changed over time helps identify whether national dental policies and access to care have improved. The study aimed to assess temporal changes in oral health-related quality of life (OHRQoL) and identify associated risk indicators using the short Oral Health Impact Profile (OHIP-14) instrument among Australian adults.

Data were sourced from the two most recent nationally representative surveys in Australia: National Survey of Adult Oral Health, NSAOH-1 (2004-06) and NSAOH-2 (2017-18). Both are population-based cross-sectional studies conducted in Australia, targeting adults aged 15 years and older. The outcome of interest was oral health-related quality of life (OHRQoL), measured using the validated short-form Oral Health Impact Profile (OHIP-14). Survey-weighted negative binomial regression models were employed to estimate both unadjusted and adjusted mean ratios (MRs) and their 95% confidence intervals (CIs) for OHIP-14 scores. Blinder-Oaxaca decomposition analysis was used to assess the contribution of changes in measured population characteristics to differences in mean OHIP-14 scores between two surveys.

In total, 4,170 participants completed the OHIP-14 questionnaire in 2004-06, and 2,836 did so in 2017-18. Between the two survey waves, the mean OHIP-14 score decreased from 7.3 to 5.5. After adjusting for all covariates, participants in NSAOH-1 had a 61% higher mean OHIP-14 score compared to those in NSAOH-2 (MR = 1.61; 95% CI: 1.53-1.70). Higher OHIP-14 scores were found among older adults, lower-educated, lower-income individuals, those with poorer health, smokers, frequent toothache sufferers, and people whose last dental visit was for a problem. The decomposition analysis showed that 41% of the difference in mean OHIP-14 scores was explained by measured population characteristics, Household income, and usual reason for dental visiting made the largest contributions to the explained component (80%), followed by smoking status (15%) and education level (9%).

OHRQoL among Australian adults improved over 14 years, reflected by lower mean OHIP-14 scores in NSAOH-2 than NSAOH-1. However, poorer OHRQoL remained associated with older age, female sex, socioeconomic disadvantage, poorer self-rated health and oral health, smoking, toothache, and problem-oriented dental visiting. Decomposition analysis suggested that changes in income and dental visiting patterns partly explained this improvement.