Jarman underprivileged area scores, tooth decay and the effect of water fluoridation.

OBJECTIVE

To examine the association between dental caries and Jarman underprivileged area scores at regional, district and electoral ward level and explore any possible relationship with water fluoridation.

DESIGN

An ecological study using the English results from the NHS dental surveys on 5-year-old children in 1991/2 and 1993/4, and the survey of 12-year-old children in 1992/3. Jarman underprivileged area scores were used from the 1991 census.

SETTING

The study used former English health authority regions and districts. The electoral wards were in non-fluoridated Salford and Trafford and Liverpool, and fluoridated Newcastle and North Tyneside.

SUBJECTS

The random sample of 5-year-old children examined in 1991/2 and 1993/4, and 12-year-old children in 1992/3, in studies coordinated by the British Association for the Study of Community Dentistry.

OUTCOME MEASURES

Correlations between regional, district and electoral ward mean dmft/DMFT and Jarman underprivileged area scores.

RESULTS

Significant correlations were demonstrated at a regional level in 5-year-old children in 1991/2, district level in 5-year-old children in 1991/2 and 1993/4 and at electoral ward level in both age groups in 1992/3 and 1993/4. Correlation coefficients varied between r = 0.88 to r = 0.46. Multiple linear regression at electoral ward level showed significant interactions between Jarman scores and water fluoridation. There was an average 44 per cent and 43 per cent reduction in caries in fluoridated electoral wards in 5- and 12-year-old children respectively. In deprived electoral wards, with a Jarman score of 40, the reduction in caries increased to 54 per cent and 56 per cent for 5- and 12-year-old children respectively.

CONCLUSIONS

Dental caries was associated with Jarman underprivileged area scores. The differential efficacy of fluoridation to deprived areas was demonstrated at electoral ward level. Water fluoridation was confirmed as an evidence based intervention which has halved the amount of tooth decay in 5- and 12-year-old children.