Abstract
Aim
The aim of this research was to determine the prevalence, natural history, antecedents, associations, and impacts of xerostomia on oral health in a longitudinal cohort of adults in their thirties from the Dunedin Multidisciplinary Health and Development Study (DMHDS) in New Zealand.
Methods
The data were collected from 972 Study members at age 32 and 961 Study members at age 38 through face-to-face interviews, self-administered questionnaires, and clinical assessments. Information was analysed using the Statistical Package for the Social Sciences (SPSS) version 17.0 (SPSS Inc., Chicago, IL, USA). Univariate analysis was undertaken to describe the sociodemographic characteristics of the sample followed by bivariate analysis and one-way analysis of variance (ANOVA) to examine the associations between the dependent variable (xerostomia) and the independent variables. Chi-square tests were used to examine the statistical significance in differences found with a p value of <0.05 considered statistically significant. Exploratory data analysis (automatic interaction detection, using the exhaustive CHi-squared Automatic Interaction Detection (CHAID) procedure in the SPSS Answer Tree) was used to identify associations between medication exposure and the prevalence of xerostomia. Multivariate analyses were undertaken through logistic regression for predicting the putative risk factors for xerostomia prevalence at age 32 and 38 and the oral health impacts while controlling for confounders with Nagelkerke’s R2 used to estimate the amount of variance explained by each model. Odds ratio was computed to assess the strength of these relationships. Ethics approval for the DMHDS was obtained from the Otago Regional Ethics Committee for each assessment phase.
Results
One in ten Study members were xerostomic by age 38, with nearly 13% increase in the prevalence percent since age 32. One in twenty-five had xerostomia at both ages, one in twenty had remitted, and one in fifteen were incident cases of xerostomia between age 32 and 38. Prevalence of xerostomia at age 32 or 38 was associated with low socio-economic status, smoking, long-term smoking, taking 1+ medications from any source, taking 1+ prescription drugs, taking more number of medications, and dental anxiety. Remission, incidence or prevalence of xerostomia at both ages was associated with those taking 1+ prescription drugs. The medication category of antidepressants accounted for the greatest difference in xerostomia, followed by bronchodilators and nutrient supplements (CHAID analyses). At age 32, those of medium SES, those taking 1+ antidepressants or those taking 1+ nutrient supplements had greater than twice the odds of being xerostomic when controlled for other covariates. At age 38, those taking antidepressants at age 38 or those taking bronchodilators at both ages had greater odds of being xerostomic when controlled for other confounding factors. Xerostomic individuals rated poorer self-reported oral health, were more likely to experience one or more oral health impacts and one or more Oral Health Impact Profile (OHIP) impacts across all subscales and high rates of dental caries. A strong association between xerostomia and oral health-related quality of life (OHRQoL) was observed when controlled for indicators of poor clinical oral health such as sex, smoking status, SES, dentition status, and periodontal disease.
Conclusion
Xerostomia is not a trivial condition or a condition associated only with old age, but a condition that is prevalent at a younger age. Once the condition presents, it either worsens or ameliorates, or continues to persist. It is no longer considered a condition of an unknown aetiology but one that has known underlying risk factors. Hence, it is imperative that the assessment of xerostomia is included in the routine practice of dentistry. Xerostomia has a major impact on oral health and overall well-being. The earlier the condition is diagnosed, the better it can be managed, thus improving the overall well-being of the individual.