Objectives: Although cost-utility analysis (CUA) has been
recommended by some experts as the preferred technique for economic
evaluation, there is controversy regarding what costs should be included and
how they should be measured. The purpose of this study was to: a) identify the
cost components that have been included in published CUAs; b) catalogue the
sources of valuation used; c) examine the methods employed for estimating
costs; and d) explore whether methods have changed over time.
Methods: We conducted a comprehensive search of the published
literature and systematically collected data on the cost estimation of CUAs.
We audited the cost estimates in 228 CUAs.
Results: In most studies (99%), analysts included some direct
healthcare costs. However, the inclusion of direct non-healthcare and time
costs (17%) was generally lacking, as was productivity costs (8%). Only 6% of
studies considered future costs in added life-years. In general, we found
little evidence of change in methods over time. The most frequently used
source for valuation of healthcare services was published estimates (73%). Few
studies obtained utilization data from RCTs (10%) or relied on other primary
data (23%). About two-thirds of studies conducted sensitivity analyses on cost
Conclusions: We found wide variations in the estimation of costs
in published CUAs. The study underscores the need for more uniformity and
transparency in the field, and continued vigilance over cost estimates in CUAs
on the part of analysts, reviewers, and journal editors.