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The CATFISH study: An evaluation of a water fluoridation program in Cumbria, UK
Michaela Goodwin1, Tanya Walsh1, William Whittaker2
1Division of Dentistry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
Insights
Water fluoridation showed a beneficial effect on children's dental health, reducing caries experience in both younger and older cohorts. However, its impact was smaller than previously reported, necessitating consideration alongside other preventive measures.
Area of Science:
- Public Health
- Pediatric Dentistry
- Epidemiology
Background:
- Community water fluoridation is a key public health strategy for preventing dental caries.
- Contemporary caries levels are lower due to widespread fluoride toothpaste use, potentially altering the impact of water fluoridation.
- Assessing the effectiveness of water fluoridation in current conditions is crucial for public health policy.
Purpose of the Study:
- To evaluate the effectiveness of a community water fluoridation program on contemporary child populations.
- To assess both systemic and topical effects of water fluoridation on dental caries in children.
- To compare caries experience in children exposed to fluoridated water versus those in control groups.
Main Methods:
- A longitudinal prospective cohort study design was employed in Cumbria, England.
- Two cohorts were recruited: a Birth Cohort (conceived after fluoridation reintroduction) and an Older Cohort (aged ~5 years at reintroduction).
- Caries experience in primary and permanent teeth was the primary outcome, analyzed using regression models.
Main Results:
- The Birth Cohort showed a beneficial effect of water fluoridation (adjusted OR 0.74), with 17.4% experiencing caries versus 21.4% in the control group.
- The Older Cohort also demonstrated a beneficial effect (adjusted OR 0.80), with 19.1% experiencing caries versus 21.9% in the control group.
- Both cohorts showed a beneficial effect on decayed, missing, or filled teeth (dmft/DMFT) counts (IRR 0.61 and 0.69, respectively).
Conclusions:
- Water fluoridation demonstrated a positive impact on reducing caries prevalence in children, though the effect was less pronounced than in historical studies.
- The findings highlight the need to consider the clinical significance of water fluoridation's benefits in conjunction with other preventive dental measures.
- The study did not find conclusive evidence that water fluoridation's effectiveness varied significantly across different socioeconomic deprivation levels.
Objectives:
The objective was to assess the effectiveness of a Water Fluoridation program on a contemporary population of children.
Methods:
The study used a longitudinal prospective cohort design. In Cumbria, England, two groups of children were recruited and observed over a period of 5-6 years. The Birth Cohort consisted of families recruited from two hospitals in Cumbria where children were conceived after water fluoridation was reintroduced. The systemic and topical effects of community water fluoridation were evaluated in the Birth Cohort. The Older Cohort were approximately 5 years old and recruited from primary schools in Cumbria, shortly after water fluoridation was reintroduced. The predominantly topical effects of fluoridated water were evaluated in the Older Cohort. The primary outcome was the proportion of children with clinical evidence of caries experience in their primary (Birth Cohort) or permanent teeth (Older Cohort). Unadjusted and adjusted regression models were used for analysis.
Results:
The final clinical examinations for the Birth Cohort involved 1444 participants (mean age 4.8 years), where 17.4% of children in the intervention group were found to have caries experience, compared to 21.4% in the control group. A beneficial effect of water fluoridation was observed adjusting for deprivation (a socioeconomic measure), sex, and age, (adjusted odds ratio 0.74 95% CI 0.55 to 0.98). The final Older Cohort clinical examinations involved 1192 participants (mean age 10.8 years) where 19.1% of children in the intervention group were found to have caries experience compared to 21.9% in the control group (adjusted odds ratio 0.80, 95% CI 0.58 to 1.09). For both the Birth Cohort and Older Cohort there was evidence of a beneficial effect on dmft/DMFT count (IRR 0.61, 95% CI 0.44, 0.86) and (IRR 0.69, 95% CI 0.52, 0.93) respectively. No conclusive proof was found to indicate that the effectiveness of water fluoridation differed across area deprivation quintiles.
Conclusions:
In the contemporary context of lower caries levels and widespread use of fluoride toothpaste, the impact of water fluoridation on the prevalence of caries was smaller than previous studies have reported. It is important to consider the clinical importance of the absolute reduction in caries prevalence against the use of other dental caries preventive measures.
