Incorporating the economic evidence in systematic reviews of interventions: an example from a systematic review in prophylaxis of respiratory syncytial virus infection

Article type
Authors
Rojas MX1, Rueda JD1, Andabaka T2
1Department of Clinical Epidemiology and Biostatistics. Pontificia Universidad Javeriana, Colombia. Andean Branch of the Iberoamerican Cochrane Centre
2School of Medicine. University of Split, Croatia
Abstract
Background: In order to address economic issues within a systematic review (SR) of interventions, a SR of economic evaluation (EE) studies focusing on the same interventions might be carried out. The value of a SR of EEs is still open to debate. However, in some cases undertaking a SR of EEs is fundamental due to the economic impact that the new intervention could have, and the number of EE assessing its cost-effectiveness that are published. In those cases the synthesis of evidence will be more useful than that available from individual studies.

Objectives: To describe methodological challenges of synthetizing the economic evidence, given the disparities across EEs, while performing a SR of interventions. To illustrate a coherent way of incorporating economic evidence into the SRs.

Methods: Selection of studies, its critical appraisal and the data extraction from included studies was performed independently by two reviewers and disagreements were resolved by a third reviewer. Only full EE (cost-effectiveness/cost-utility analyses) were included. The quality was assessed using an adapted Drummond’s checklist. Characteristics and results of EEs were presented in a descriptive way in tables, separately for three subgroups, according to the baseline risk of population. The values of incremental cost-effectiveness ratios provided by authors were adjusted for the time value of money, by using the appropriate gross domestic product deflator, and were presented in 2011 EUR.

Results: A total of 34 EE studies were included. The procedures undertaken for implementing the above mentioned methods in a SR assessing the effect of immunoprophylaxis in preventing the severe respiratory syncytial virus infection, will be presented.

Conclusions: This example could be used as a guide to non-health economist reviewers within the Cochrane Collaboration, in terms of issues to be considered when undertaking a systematic review of economic evaluations as part of their SR of interventions.