Introduction: Systematic reviews of economic evaluations are useful for synthesizing economic evidence about health interventions and for informing evidence-based decisions. Areas covered: As there is no detailed description of the methods for performing a systematic review of economic evidence, this paper aims to provide an overview of state-of-the-art methodology. This is laid out in a 5-step approach, as follows: step 1) initiating a systematic review; step 2) identifying (full) economic evaluations; step 3) data extraction, risk of bias and transferability assessment; step 4) reporting results; step 5) discussion and interpretation of findings. Expert commentary: The paper aims to help inexperienced reviewers and clinical practice guideline developers, but also to be a resource for experts in the field who want to check on current methodological developments. ARTICLE HISTORY

Introduction: This article is part of the series "How to Prepare a Systematic Review (SR) of Economic Evaluations (EE) for Informing Evidence-based Healthcare Decisions" in which a five-step-approach for conducting a SR of EE is proposed. Areas covered: This paper explains the data extraction process, the risk of bias assessment and the transferability of EEs by means of a narrative review and expert opinion. SRs play a critical role in determining the comparative cost-effectiveness of healthcare interventions. It is important to determine the risk of bias and the transferability of an EE. Expert commentary: Over the past decade, several criteria lists have been developed. This article aims to provide recommendations on these criteria lists based on the thoroughness of development, feasibility, overall quality, recommendations of leading organizations, and widespread use. ARTICLE HISTORY

This article is part of the series "How to prepare a systematic review of economic evaluations (EES) for informing evidence-based healthcare decisions", in which a five-step approach is proposed. Areas covered: This paper focuses on the selection of relevant databases and developing a search strategy for detecting EEs, as well as on how to perform the search and how to extract relevant data from retrieved records. Expert commentary: Thus far, little has been published on how to conduct systematic review EEs. Moreover, reliable sources of information, such as the Health Economic Evaluation Database, have ceased to publish updates. Researchers are thus left without authoritative guidance on how to conduct SR-EEs. Together with van Mastrigt et al. we seek to fill this gap.

Although the routine starting point of an analysis should always be an unadjusted analysis of the cost effectiveness, a baseline difference between treatment groups should be adjusted for. This should be done by reported patient characteristics or, when these are not sufficiently present, by baseline costs as a substitute. This adjustment should be carried out most preferably with a regression-based method.

ObjectivesTo assess and explore over 1 year poststroke (1) the societal costs, (2) changes in costs and quality of life (QoL) and (3) the relation between costs and QoL.DesignThe current study is a burden of disease study focusing on the cost-of-illness (in Euros) and QoL (in utilities) after stroke.SettingAdult patients with stroke were recruited from stroke units in hospitals and followed for 1 year.ParticipantsData were collected from 395 patients with stroke.Main outcome measuresCosts and QoL expressed in utilities.MethodsCost categories were identified through a bottom-up method. The Dutch 3-level 5-dimensional EuroQol (EQ-5D-3L) was used to calculate utilities. Non-parametric bootstrapping was applied to test for statistical differences in costs. Subgroup analyses were performed to identify predictors for costs and QoL. Robustness of results was tested via sensitivity analyses.ResultsThe total societal costs for 1 year poststroke were €29 484 (n=352) of which 74% were in the first 6 months. QoL remained stable over time. The discharge location was a significant predictor for cost and QoL; men had a significantly higher QoL than women and younger patients (<65) had significantly more costs than older patients (>65). Ceiling effects appear on all dimension of the EQ-5D-3L. Costs and QoL show a weak correlation (r=−0.29). Sensitivity analyses showed robustness of results.ConclusionsWe found lower patient costs and higher QoL than expected. This may be explained by the good state of health of our study population and by change in the Dutch healthcare system, which has led to considerable shorter hospitalisation poststroke. Future research must question the use of the EQ-5D-3L in a similar population due to ceiling effects.Trial registration numberNTR3051.