Background: The Institute for Quality and Efficiency in Health Care (IQWiG) is an independent scientific institute responsible for the evaluation of health care interventions. Transparency concerning all steps of the evaluation is a high priority for the institute. A comprehensive literature search and the subsequent selection of relevant trials are important steps during IQWiG's assessment process.
Objectives: To improve transparency of the trial selection process by introducing an additional selection step and reporting all reasons for exclusion of possibly relevant electronic search records. This step identifies studies relevant to the topic based on a set of minimum inclusion criteria.
Methods: Based on the objective, a new process flow for trial selection was designed. To facilitate the conduct of trial selection according to this more complex method, a database for the selection process was developed. The process and the database were pilot tested in a drug evaluation project.
Results: The new selection process starts with the identification of studies relevant to the evaluated topic based on minimum inclusion criteria (indication, evaluated drug, human study). From this pool, final study selection using the full set of inclusion/exclusion criteria is performed. In the pilot project, out of 511 electronic search hits, 162 were relevant to the topic, and 4 studies met all inclusion criteria.
Conclusions: The new process improves transparency of trial selection by providing a break-down of the original search result into studies irrelevant to the investigated topic and studies meeting minimum inclusion criteria. The database used for selection is an easy-to-use tool for the detailed documentation of this complex process.