OBJECTIVES: Randomised controlled trials (RCTs) are the cornerstone of evidence generation for decisions on whether to approve or reimburse a treatment. However, real-world data (RWD) is emerging as an additional evidence source for health technology assessment (HTA) agencies. For example, in rare diseases and indications, international RWD may be the best information available but may be geographically distinct or otherwise not representative of the target population. This can create uncertainty about validity of the results. Applying transportability methods to a suitable data source can help to overcome this uncertainty by providing an estimate of what the treatment effect would have been had the original study been conducted in the target population by adjusting for differences between the two populations. Here we conducted a scoping review to identify and describe studies applying transportability methods to RWD.

METHODS: PubMed/Medline, Cochrane and Google Scholar were searched using predefined terms and reference lists scanned for articles in English applying transportability methods in real-world contexts, either from RCT to RWD or from RWD to RWD. Data were extracted on the transportability scenario considered, transportability method used and therapeutic area examined.

RESULTS: A total of 13 studies were included. Most (9 out of 13) transported a treatment effect from an RCT to a target population identified in RWD. Weighting-based approaches were the dominant adjustment method employed. The included studies cut across several therapeutic areas, including HIV, breast cancer and schizophreniform disorder.

CONCLUSIONS: The evidence base on real-world applications of transportability methods is limited. More examples of transporting results from RWD studies are required to support the use of these methods for decision making in HTA. In the meantime, HTA agencies require guidance to assess and manage submissions that utilise different sample and target populations to prevent unnecessary delay in decisions and, ultimately, treatment access.