Use of Quality-Adjusted Tooth Years as an Outcome Measure of Periodontal Treatment: A Quasi Experimental Study

Abstract

Aim: To develop a simple approach to estimate quality-adjusted tooth years of teeth (QATY) treated for periodontitis and determine gains in QATY after undergoing cause-related periodontal therapy (CRPT). Quality-adjusted life years (QALY) gained for these patients were also determined. Materials and Methods: Patients newly diagnosed with periodontitis (n = 165, 58.8% females, mean age 43.3 years) were recruited from periodontal specialist clinics. They received CRPT within a period of one year. We used the EuroQoL 5 Dimension (EQ-5D) and the Malaysian Oral Health Impact Profile (OHIP-14) indexes to measure changes in quality-of-life after one year of periodontal treatment. We then used these two scores to calculate their respective utilities and subsequently calculated QALY and QATY. Results: Proportions of deep periodontal sites (≥ 4 mm) decreased from 32.7% to 23.2% and patients gained an average of 0.3 mm of clinical attachment level per tooth at post-treatment follow-up. Improvements in means of OHIP-14 scores from 20.30 to 12.7 were consistent with changes in EQ-5D utilities from 0.81 to 0.91. Treated teeth gained 20.4 years for longevity while patients gained 17 QATYs. This is in line with the increase of 3.8 QALYs. Both treatment outcomes and clinical parameters were statistically significant at P < .0001. Conclusions: The method of estimating QATY using utilities derived from OHIP-14 combined with tooth life expectancy demonstrated that it may be used to measure effective treatment outcomes and is found to be consistent with improvements in QALY scores as calculated using EQ-5D-3L.