More pragmatic randomized studies with a focus on registry-based trials

Background Randomized controlled trials (RCTs) that are highly restrictive in terms of study design, with highly selected participants and conditions, produce results whose applicability to routine clinical care and usefulness for reimbursement decisions is sometimes questioned. Objectives In view of the background mentioned above, do more pragmatic RCTs and registry-based RCTs offer potential solutions? What are the opportunities and risks associated with more pragmatic studies and which methodological aspects should be given special attention? Methods Narrative review of more pragmatic RCTs and registry-based RCTs with presentation of the Pragmatic Explanatory Continuum Indicator Summary 2 (PRECIS-2) approach, presentation of example studies, and discussion of methodological aspects. Results Clinical RCTs for comparative effectiveness evaluation are located on a continuum from "very pragmatic" to "very explanatory". No consented threshold exists from which an RCT is considered pragmatic. More pragmatic RCTs are often characterized by less selected but larger patient groups, embedding into a normal care setting, and patient-relevant outcomes. They usually dispense with longer-term assurance of patient adherence to the initially assigned treatment, blinding, and resource intensive intermediate examinations. However, this can lead to problems in interpretation, especially if no differences between interventions are shown. Conclusions More pragmatic RCTs and registry-based RCTs have the potential to become an important basis for decision-making in clinical practice, but also for health policy and reimbursement issues. However, in order to realize this potential, a number of hurdles-especially legal ones-have to be abolished.