Register-based randomized trials: the best of both worlds?

15.09.2022 17:45

IQWiG authors present the advantages and disadvantages of study designs that combine explanatory and pragmatic aspects. RCTs based on registers in particular have potential.

Randomized controlled trials (RCT), such as those required for the approval of new drugs, are often criticized because they are too complex, too lengthy and - because of the highly controlled study conditions - hardly transferable to everyday clinical care. Critics prefer so-called pragmatic studies in which “real world evidence” can be obtained.

In an article in the magazine Prevention and Health Promotion, Stefan Lange, deputy director of the Institute for Quality and Efficiency in Health Care (IQWiG), and his colleague Jörg Lauterberg present the spectrum that lies between the pure forms of these two study designs. With an overly pragmatic design, you risk a significant loss of meaningfulness because you control too few parameters and may therefore no longer be able to separate different effects from one another. In order to be able to make meaningful statements, you have to include a lot of patients. This calls into question the credo that pragmatic studies are easier to implement.

So-called register-based (RRCT) are intended to combine the best of both worlds - i.e. to provide reliable findings that can be transferred to routine care - and are also less complicated to carry out because they rely on existing structures from patient registers. The authors appreciate the potential of such a design, but point out that the data quality of the basic variables and outcomes in many registries is not yet sufficient for good RRCT.

Finally, Lange and Lauterberg suggest a modification of the legislation on so-called in-use data collection for drugs with very limited evidence: randomized comparisons have so far been expressly excluded. In the authors' opinion, it should be possible to continue researching such new active ingredients using relatively uncomplicated and at the same time meaningful register-based methods.