Factors associated with dental caries among institutionalized residents with schizophrenia in Taiwan: a cross-sectional study

BACKGROUND Little research has been done on the relationship between dental caries and the personal characteristics of institutionalized residents diagnosed with schizophrenia. This study investigates the individual and treatment factors associated with the dental caries among institutionalized residents with schizophrenia in Taiwan. METHODS An oral health survey of institutionalized residents with schizophrenia in the largest public psychiatric hospital was conducted in Taiwan in 2006. Based on this data, multiple logistic analyses were used to determine the relationship between some explanatory variables and the outcome variables of dental caries among subjects with schizophrenia. RESULTS Among the 1,108 subjects with schizophrenia, age was the only variable independently associated with DMFT > 8 (OR = 7.74, 95% CI = 3.86-15.55, p < 0.001 in comparison to residents aged 65 + years vs. 20-44 years; OR = 3.06, 95% CI = 2.03-4.61, p < 0.001 in comparison to residents aged 55-64 years vs. 20-44 years) after making adjustments for other explanatory variables. In addition, those with an education of only elementary school (OR = 1.67, 95% CI = 1.08-2.56, p = 0.021), low income (OR = 1.58, 95% CI = 1.02-2.44, p = 0.039), and length of stay (LOS) of > 10 years (OR = 2.09, 95% CI = 1.30-3.37, p = 0.002) were associated with a care index < 54.7%. Older age, lower educational level, and longer hospital stays were associated with number of remaining teeth being < 24. CONCLUSIONS Aging was the most important factor related to a high level of dental caries. Low educational level, low income, and LOS were also associated with the indicators of dental caries among institutionalized subjects with schizophrenia. It is necessary to address the treatment factors such as prolonged stay in institutions when decision-makers are planning for preventive strategies of oral health for institutionalized residents with schizophrenia.