Health economic evaluation methods for decision-making in preventive dentistry

Sammanfattning: The aims of this thesis were to evaluate caries-preventive measures from a societal perspective, to demonstrate the use of resources in preventive dentistry, to develop and discuss techniques suitable for evaluating dental care costs and outcomes, and to test costs and consequences within a health economic decision model adapted to preventive dental care.The thesis is based on three separate studies with three separate cohorts. In the first study, performed at a single dental clinic, analysis was made of data on dental caries progression over four years in 92 adolescents, along with the use of resources for preventive treatment. In the second study, data from the intervention study “Evaluation of caries-preventive measures” (performed between 1995 and 1999 at 26 dental health clinics throughout Sweden) were used for economic evaluation. Three different approaches to calculating unit cost were discussed, each of which reflect the differences in treatment costs as influenced by the practitioner’s level of skill and competence (salary) and by methods of handling overhead cost allocation. These methods seem useful for evaluating costs in cost-effectiveness analysis (CEA) and cost-benefit analysis (CBA). The CEA showed an incremental cost-effectiveness over four years of SEK 2 043' per averted decayed (D) enamel (e) and dentine caries, missing (M) and filled (F) surface (S) (DeMFS). In the third study, 82 19-year-old individuals agreed to participate in a pilot exploratory case-control study. Individuals with high caries experience formed the test group while the control group consisted of individuals with no caries experience. To explore whether any differences existed between these two groups in perceived oral health-related quality of life (OHRQOL), two OHRQOL measures were used. Additionally, the willingness of these individuals to pay (WTP) for a preventive strategy was elicited using the contingent valuation method (CVM) within a cost-benefit approach. Using these WTP values, the cost-benefit analyses showed positive net social benefit (NSB) values for both study groups, meaning that the benefits of prevention exceeded the costs. A new outcome measure, Value of Statistical Oral Health (VOSOH), was also presented.Consideration was also made, within the economic framework fundamental to this thesis, of the trend away from a strictly bio-medical paradigm towards a biopsychosocial perspective. The health economic decision model encompasses a number of different techniques for comparing costs with consequences, each with its own advantages and disadvantages and each with its own field of application. These techniques should be seen as complementary rather than competing. Preventive dentistry plays a central role in Swedish dental health care, and it is important that resources are used properly. Accurate evaluation methods are necessary in order to improve the basis for public decision-making; the methods proposed in this thesis seem to be of potential use in this endeavour.'SEK8.54 = US$1 (December 1999).