‘Characteristics of included studies tables’ provide a natural place in a Cochrane review to present details of the characteristics of included health economics studies, such as year of study; details of interventions and comparators; study design; data sources; jurisdiction and setting; analytic perspective and time horizon (see also Section 15.4.2). Authors may also consider including additional tables to summarize checklists completed to inform assessments of the methodological quality of included health economics studies (see also Section 15.5.2).
The results of included health economics studies can be summarized using either ‘Characteristics of included studies’ tables, Additional tables, or both. In either case, where possible, point estimates of measures of items of resource use or costs should be presented with associated measures of uncertainty for both the target intervention and each of its comparators, as well as point estimates of incremental costs and/or cost-effectiveness, again with associated measures of uncertainty. It is also important to state the currency and price year alongside estimates of costs and/or incremental costs (if reported).
It may be possible to convert cost estimates to a common currency and price year, in order to facilitate comparison of estimates collected from different studies. An international exchange rate based on Purchasing Power Parities (PPPs) should be used to convert cost estimates to a target currency, and gross domestic product (GDP) deflators (or implicit price deflators for GDP) should be used to convert cost estimates to a fixed price year. Data sets containing PPP conversion rates and GDP deflator values are available from the International Monetary Fund in the World Economic Outlook Database (updated biannually: see www.imf.org/external/data.htm). Conversion of cost estimates to a common currency and price year should only be performed in consultation with an experienced health economist. CCEMG will aim to issue further methods guidance on this topic in due course.