The value of arthroplasty registry data

Arthroplasty registries play a critical role in improving the outcome of joint replacement surgery. They provide unique community-based comparative data that enables individual surgeons to identify best practice that is relevant to their own approach to arthroplasty surgery. Registries simultaneously compare the effect of multiple factors on the outcome of joint replacement, and through ongoing monitoring are also sensitive to the impact of changing practice. The information they provide is known to change practice in a beneficial manner. There continues, however, to be an ongoing debate about the value of registry data.

Traditionally, the value of clinical information has been determined by its standing in the hierarchy of levels of clinical evidence. The underlying basis for this hierarchy is the ability of the data to establish causality with respect to outcome. This has been specifically linked to study design, with a randomized controlled trial (RCT) being recognized as having the greatest capacity to achieve this. If the clinical evidence approach is used to categorize registry-derived data, there is no option other than to regard this information as coming from an observational study. As such, registry data would be considered as having lower value than an RCT or a systematic review of RCTs. This could be correct with respect to ability to establish causality. However, is this clinically relevant and is it the best approach to determine comparative value of information obtained from registries and clinical trials?