A longitudinal study of factors that influence oral health-related quality of life

Abstract

Introduction: Several factors that influence oral health-related quality of life (OHRQoL) have been reported in cross-sectional studies but a conclusion has not been reached. It has been recommended that a longitudinal population-based study should be conducted in this research area. Objectives: This is a longitudinal study aiming to investigate the possible factors that influence OHRQoL. Methods: A representative sample was selected from school children in Hong Kong. Subjects were followed up from age 12 to 18. Sociodemographic factors including age, gender, parents’ education, and household income were collected. Periodontal status and caries experience were assessed according to WHO criteria. Malocclusion was assessed by four orthodontic indices. OHRQoL was measured by Child Perceptions Questionnaire (CPQ11-14) at ages 12 and 15, and Oral Health Impact Profile (OHIP-14) at age 18. Results: A total of 589 subjects (305 females, 284 males) were recruited at age 12. The participants at ages 15 and 18 were respectively 364 (186 females, 178 males) and 300 (165 females, 135 males). In these subjects, 331 (172 females and 159 males) were followed up from age 12 to 15, 204 (114 females and 90 males) were followed up from age 15 to 18, and 188 (106 females and 82 males) were followed up across all three surveys. Cross-sectional analysis showed that males were more tolerant of oral symptoms when compared with females at ages 12 and 15. Parents’ education had an impact on children’s OHRQoL at ages 12 and 18. Mother’s education was more associated with children’s OHRQoL at age 12; the effect of mother’s education was positive whereas the effect of father’s education was negative. Both mother’s and father’s education had some positive effect on children’s OHRQoL at age 18. Household income had a positive effect on OHRQoL only at age 18. Caries affected OHRQoL at age 12, while periodontal status affected OHRQoL at ages 12 and 15. Malocclusion had a negative effect on OHRQoL at ages 12, 15 and 18. Longitudinal analysis showed that age, gender, periodontal status, and malocclusion were influence factors of OHRQoL. Age 15 seemed to be the time when subjects’ OHRQoL changed most. This was shown from two aspects. First, subjects tended to have a worse OHRQoL at age 15 than at ages 12 and 18. Second, the influence of gender was only shown from age 12 to 15; males were more tolerant of oral symptoms than females in this age period. Periodontal status and malocclusion had a negative effect on OHRQoL after correcting other confounding factors. Conclusion: Among sociodemographic factors, age and gender were the principle influence factors of OHRQoL. Parents’ education mainly had an effect on children’s OHRQoL at age 12, while household income mainly had an effect at age 18. Among clinical factors, malocclusion and periodontal status were the principle influence factors of OHRQoL. Caries only had some effect on OHRQoL at age 12 in this cohort.