Mapping caries prevalence and water distribution in Wales-- Iechyd Morgannwg Health Authority as a case study.

STUDY OBJECTIVE To investigate the use of mapping in targeting water fluoridation to areas of high need in lechyd Morgannwg Health Authority, as defined by the upper quintile of the distribution of the percentage with dmft > 0 in dental planning areas. DESIGN Data from the 1997/98 childhood dental epidemiological survey and the Welsh Water Company water supply zones (as at 1997) were plotted. Maps were generated to identify the relationship between water supply areas, water supply sources and areas of high caries prevalence. SETTING Maps focussed upon one Welsh health authority, Iechyd Morgannwg Health Authority. Examinations for the childhood epidemiology programme took place in schools. PARTICIPANTS 5-year-old children examined in the 1997/98 survey. MAIN RESULTS Data presented by very different geographical boundaries were compared without having to carry out complex mathematical transformations. It was possible to quickly identify areas of Iechyd Morgannwg Health Authority with high levels of oral disease, the associated water supply zones and their water treatment centres with a view to possible future targeting of fluoridation. The maps identify the possibility of dilution, when a particular water supply zone was served by more than one treatment works. CONCLUSIONS This technique enables disparate and complex data bases to be combined enabling visual analysis of the results. The maps facilitate decision making as to the most beneficial areas to fluoridate. The results will be of value in determining the feasibility and targeting of water fluoridation in Wales.