Systematic review of health state utility values in metastatic non-small cell lung cancer with a focus on previously treated patients

Background: Health state utility values (HSUVs) are an important input to economic evaluations and the choice of HSUV can affect the estimate of relative cost-effectiveness between interventions. This systematic review identified utility scores for patients with metastatic non-small cell lung cancer (mNSCLC), as well as disutilities or utility decrements relevant to the experience of patients with mNSCLC, by treatment line and health state. Methods: The MEDLINE (R), Embase and Cochrane Library databases were systematically searched (September 2016) for publications describing HSUVs in mNSCLC in any treatment line. The EQ-5D website, the School of Health and Related Research Health Utilities Database (ScHARRHUD) and major pharmacoeconomic and clinical conferences in 2015-2016 were also queried. Studies in adults with previously treated mNSCLC were selected for further analysis. The information extracted included study design, description of treatment and health state, respondent details, instrument and tariff, HSUV or (dis) utility decrement estimates, quality of study, and appropriateness for use in economic evaluations. Results: Of 1883 references identified, 36 publications of 34 studies were included: 19 reported EQ-5D scores; eight reported HSUVs from valuations of vignettes made by members of the public using standard gamble (SG) or time trade-off (TTO); two reported SG or TTO directly elicited from patients; two reported EQ-5D visual analogue scale scores only; one reported Assessment of Quality of Life instrument scores; one reported HSUVs for caregivers to patients with mNSCLC using the 12-item Short-Form Health Survey; and one estimated HSUVs based on expert opinion. The range of HSUVs identified for comparable health states showed how differences in study type, tariff, health state and the measures used can drive variation in HSUV estimates. Conclusions: This systematic review provides a set of published HSUVs that are relevant to the experience of adult patients previously treated for mNSCLC. Our review begins to address the challenge of identifying reliable estimates of utility values in mNSCLC that are suitable for use in economic evaluations, and also highlights how varying estimates result from differences in methodology.