Showing papers by "A. John Spencer published in 1995"

Associations between exposure to fluoridated drinking water and dental caries experience among children in two Australian states.

Abstract: Objectives: This study assessed associations between exposure to fluoride in water and dental caries experience among children in two Australian states. Methods: Cross-sectional data were obtained from 9, 690 South Australian children aged 5–15 years and 10, 195 Queensland children aged 5–12 years. School dental service practitioners recorded DMFS and dmfs data. A questionnaire to parents gained information about residential history that was used to calculate children's percent of lifetime exposed to fluoridated water. Results: Greater exposure to fluoride in water was associated with lower dmfs and DMFS in both states (P<.01), although in South Australia the effect for DMFS was statistically significant only after controlling for extent of unknown fluoridation exposure and for fluoride supplements. Caries-fluoridation associations were stronger for dmfs compared with DMFS and for Queensland (5% of population fluoridated) compared with South Australia (70% of population fluoridated). Effects for DMFS persisted after controlling for socioeconomic factors. Conclusions: Fluoridation was associated with lower caries experience. The weaker association with DMFS in South Australia may be due to less caries and more fissure sealants in that state, and is consistent with a “diffusion” effect, whereby a high proportion of the population exposed to fluoridation diminishes differences among exposure groups.

Methodological aspects of a computer-assisted telephone interview survey of oral health.

Abstract: Despite the reported benefits of computer-assisted telephone interview (CATI) methods, experiences from their use in Australian oral health surveys have not been described. This report aimed to present methodological aspects of a CATI survey conducted in the five mainland states. A response rate of 66 per cent was obtained, yielding 4050 completed interviews. Analysis revealed generally small levels of non-response bias: persons who avoided or delayed dental treatment because of cost and non-health card holders were harder to contact, while non-English speakers and persons aged 20–29 years were less likely to participate. A total of 1770 person hours of interview time was spent on the survey: 64.5 per cent of that time was spent on the telephone with an average of 10 minutes 17 seconds per call (13 minutes 37 seconds per completed call). Only seven questions had missing data for more than 1 per cent of respondents. Comprehension of questions and cooperation with the interview was rated by interviewers as ‘good’ or ‘very good’ for more than 90 per cent of respondents. The CATI method was highly efficient and yielded good quality data for the survey.

Predictors of fixed orthodontic treatment in 15‐year‐old adolescents in South Australia

Abstract: An understanding of the determinants of the provision of fixed orthodontic treatment would be beneficial in the planning of any system aimed at rationalising supply. The aim of this longitudinal study was to determine those factors which were predictive of the provision of fixed orthodontic treatment in adolescents. Baseline data, at age 13 years, on oral health, the history of orthodontic consultation and interceptive orthodontic care, a dental appearance score (DAI), socio-demographic characteristics and self and parental perceptions of both dental appearance and need for fixed orthodontic treatment were obtained from 2793 adolescents under the care of the South Australian School Dental Service who had not undergone fixed orthodontic treatment. Data on the orthodontic care provided to these adolescents in the ensuing 2 years were collected. At the end of the 24-month period 433 adolescents (15.5%) had undergone fixed orthodontic treatment. Significant bivariate associations were found between the provision of fixed orthodontic treatment and the DAI score, sex of the adolescent, familial history of fixed orthodontic treatment, income, private insurance, orthodontic consultation and interceptive orthodontic care before the age of 13 years and self and parental perceptions of both dental appearance and the need for fixed orthodontic treatment. Logistic regression was used to produce a predictive model of fixed orthodontic treatment. The model explained 30.2% of the variance, with a specificity of 0.94, a sensitivity of 0.49 and a hit rate of 0.84%. Odds ratios greater than one were found for the DAI score, private insurance, females, self and parental perception of need, higher incomes and orthodontic consultation and interceptive orthodontic care before the age of 13 years.