Estimating QALY gains in applied studies: a review of cost-utility analyses published in 2010

Abstract

Reimbursement agencies in several countries now require health outcomes to be measured in terms of quality-adjusted life-years (QALYs), leading to an immense increase in publications reporting QALY gains. However, there is a growing concern that the various 'multi-attribute utility' (MAU) instruments designed to measure the Q in the QALY yield disparate values, implying that results from different instruments are incommensurable. By reviewing cost-utility analyses published in 2010, we aim to contribute to improved knowledge on how QALYs are currently calculated in applied analyses; how transparently QALY measurement is presented; and how large the expected incremental QALY gains are. We searched Embase, MEDLINE and NHS EED for all cost-utility analyses published in 2010. All analyses that had estimated QALYs gained from health interventions were included. Of the 370 studies included in this review, 48% were pharmacoeconomic evaluations. Active comparators were used in 71% of studies. The median incremental QALY gain was 0.06, which translates to 3 weeks in best imaginable health. The EQ-5D-3L is the dominant instrument used. However, reporting of how QALY gains are estimated is generally inadequate. In 55% of the studies there was no reference to which MAU instrument or direct valuation method QALY data came from. The methods used for estimating expected QALY gains are not transparently reported in published papers. Given the wide variation in utility scores that different methodologies may assign to an identical health state, it is important for journal editors to require a more transparent way of reporting the estimation of incremental QALY gains.

Fig. 1

The growth of cost-utility analyses over the last 25 years (search for cost-utility analysis in Embase)

Fig. 2

Search diagram. CUA cost-utility analysis, QALY quality-adjusted life-year