Willingness to pay for periodontal therapy: Development and testing of an instrument

Objectives: The objective of this study was to develop and test the feasibi lity and validity of a willingness to pay (WTP) fool in a denial setting. M ethods: A questionnaire measured individuals' preferences among alternative treatments for periodontal disease and the maximum they would be willing t o pay for their treatment of choice in terms of dental insurance premiums. The questionnaire provides detailed information, in probabilistic terms, of the risks and benefits of treatment choices for moderate to advanced adult periodontitis, it was pilot tested on 23 periodontal patients and 18 denta l school faculty and staff Results: The majority (92.6%) felt the questionn aire was an accurate representation of treatments and outcomes, establishin g face and content validity. In terms of construct validity, four hypothese s were tested (1) manipulation of the outcomes of the preferred treatment f ed to a predictable shift in preferences for 38 subjects (92.7%); (2) altho ugh periodontal patients were not more likely to choose periodontal surgery than nonpatients (P=.14), those with a history of surgery were more likely to choose surgery again (P=.06); (3) WTP was positively related to income level (P=.05); and (4) subjects were willing to pay more for coverage for t hemselves than for others. Periodontal surgery was the preferred treatment for moderate to advanced periodontal disease, and was more strongly preferr ed than other choices (i.e., a higher WTP) for all income groups. The intra class correlation coefficient far treatment preferences was 0.95 (P<.001) a nd the kappa for WTP was 0.78 (P<.001). Conclusion: This pilot study suppor ts some of the criteria concerning validity of the WTP questionnaire So mea sure preferences for alternative periodontal therapies. Further testing on larger samples is required to confirm these results.