Endocrine Abstracts

We report new estimates of the disutility associated with GL and PL, and the quality of life (QoL) impact of leptin replacement therapy (LRT) based on two methods. The first approach estimates utility decrements associated with a range of impairments related to lipodystrophy through a discrete choice experiment (DCE) conducted with members of the general public; the second elicits QoL estimates from 8 PL patients using the SF-36 instrument. To characterize QoL consequences of specific impairments, a DCE was conducted with 1,000 members of the general population. Multinomial logit regression was used to estimate utility decrements associated with each impairment in quality-adjusted life-years (QALYs). While estimates of DCE-derived QALY decrements have been presented previously, the current analysis anchors the absolute value of these decrements to the UK’s EQ-5D tariff. This mapping is achieved by scaling DCE values such that the absolute value of QoL for a patient with all measured lipodystrophy impairments equals the UK valuation of the worst EQ-5D health state (−0.594). Anchoring QALY values in this manner facilitates external comparison across studies. Scaled decrements were combined with previously reported data on the prevalence of impairments among lipodystrophy patients before, and 1 year after, initiating LRT to measure the impact of LRT on QoL. Overall, QALY gains associated with LRT were estimated at 0.313 across GL patients through the DCE (from 0.466 to 0.779). Changes in ‘Inability to perform work/schoolwork’ (−0.167 decrement, 45.6% point decrease in prevalence) accounted for 24.3% of the gain. Across PL patients, QALY gains associated with LRT were estimated at 0.224 through the DCE (from 0.624 to 0.848). Changes in ‘Hyperphagia’ (−0.071 decrement, 62.5% point decrease in prevalence) accounted for 20.6% of the gain. Additionally, SF-6D-R2 utility values were derived from surveys of 8 lipodystrophy patients diagnosed with PL using the SF-36 instrument (5 treated, 3 untreated). These results support a gain from treatment of 0.21 QALYs (0.67 for treated patients and 0.46 for untreated patients), very similar to the PL gain estimated through the DCE. The results of this study suggest that lipodystrophy is associated with a large QoL impairment and that the benefits of LRT are substantial in both PL and GL patients. Additional studies are needed to further characterize the burden of lipodystrophy and the impact of LRT on quality of life.