Caries treatment in Swedish adults: effectiveness, costs and equity. A 4-year follow-up study of data from the Swedish national dental health register.

At a national level, planning and management of dental services should be based on assess- ments of equity, effectiveness and costs. In Sweden, data for the adult population are now acces- sible through The Swedish dental health register, at The National Board of Health and Welfare. This study, on two large cohorts of Swedish adults, is based on longitudinal follow-up data, retrieved from the Swedish dental health register.The aims were twofold: to assess frequencies and costs of fillings and crowns, including subsequent repair; secondly to study the relationship between preventive and restorative dental treatment.The Swedish dental health register pro- vides data on the adult population which offers a new perspective on public health aspects of management of dental care at the national level. A longitudinal, prospective study model was used to follow-up two large cohorts for over four years. In the first cohort, data on 1,088,923 adult patients were analysed with reference to provision of single crowns and fillings over a period of 42 -48 months.The second cohort comprised 1,703,147 adult patients: the data were analysed with reference to preventive interventions over a period of 48 - 54 months. Frequencies of distribution of dental care by age group showed that the cohorts were representative for the whole patient group.With respect to equity, the average number of dentist appointments per i,ooo inhabitants for all 21 regions of Sweden was 140 to 160, despite major variations in geographic conditions and population densities. With respect to effectiveness, about 76% of the teeth with index interven- tions required no additional intervention over four consecutive years of follow-up. For the remain- ing 24% of the teeth 77% had only one additional intervention. When differences of case-mix were taken into account, the costs of repairs to earlier ihterventions were basically similar, regardless of age-group.There were no gender differences. However, there were pronounced differences, of up to three intact teeth, among patients from different regions of Sweden. Follow-up of effects of caries prevention showed no gender differences. However, costs for reparative interventions increased with higher costs for preventive treatment. Moreover, the longer the interval between preventive interventions, the lower the costs for reparative interventions.The national dental health register is a potentially valuable source of data for dental research. In this study, longitu- dinal registry data on restorative and preventive treatment were retrieved and analysed, with reference to efficacy, costs and equity. The results have potential application in improving mana- gement of public dental health.