The use of meta-analysis in cost-effectiveness analysis - Issues and recommendations

Meta-analysis is used to statistically pool the results from individual stu dies, usually randomised trials, to obtain an estimate of the summary effec t size across studies. The summary measure from a meta-analysis is often us ed to derive the probability of treatment success in a cost-effectiveness a nalysis. Recently, LeLorier and colleagues questioned the ability of meta-a nalysis to accurately predict the results of a subsequent large-scale trial , implying;that the use of a summary measure from a meta-analysis may be in appropriate in an economic evaluation. We comment on this potential shortco ming by first providing an outline of the use of meta-analysis results in a cost-effectiveness analysis. Then, using examples of discrepancies between meta-analyses and subsequent large trials noted by LeLorier and colleagues , we examine the potential impact of using the results from a small trial v ersus a meta-analysis. We found that the meta-analyses were comparable to or better than small tri als at predicting the results of subsequent large trials. We, therefore, ar gue that a meta-analysis of homogeneous studies can provide a reasonable es timate of the treatment effect for use in a cost-effectiveness analysis whe n no large, definitive clinical trial has been performed. However, care mus t be taken not to overinterpret the precision of the estimate, since both t he homogeneity and quality of the primary studies need to be considered. We conclude by providing guidance on the appropriate use of summary measures derived from meta-analyses for cost-effectiveness studies.