OBJECTIVES: Single-arm real-world evidence (RWE) studies are becoming more prevalent in clinical practice. With the advent of advanced indirect treatment comparison (ITC) methods, these studies can now be included in ITC. The objective of this study is to provide our recommendations on the approach for data extraction (DE) when both comparative and single-arm RWE studies are included in ITC.

METHODS: When conducting systematic literature reviews (SLRs) for ITC in gastrointestinal disease (GID) and addiction behavior disorder (ABD), we considered two approaches for DE after identifying and including studies in the SLR: traditional and pragmatic. Traditional approach is a two-step process: (a) DE from all comparative and single-arm studies for all attributes (study characteristics, baseline data, efficacy outcomes, and safety) at the same time, and (b) conduct the ITC. Pragmatic approach is five steps process: (a) DE from all comparative studies (for all attributes) and DE from single-arm studies only for study characteristics and baseline, (b) conduct ITC based on comparative studies, (c) matching of single-arm studies (for inclusion into ITC) based on covariates of interest, (d) DE for efficacy and safety outcomes only from matched single-arm studies, and (e) conduct the ITC.

RESULTS: More than 200 studies were included in GID SLR and nearly 50 studies in ABD. In both SLRs, 77-80% were single-arm RWE studies. Traditional approach required DE from all single-arm studies. However, in the pragmatic approach, about 42% single-arm studies of GID and 27% single-arm studies of ABD were matched for ITC inclusion and required DE for outcomes of interest. Compared to traditional, the pragmatic approach provided approximately 30-40% of time savings in DE from single-arm studies.

CONCLUSIONS: This study showed that pragmatic approach could provide potential savings in DE time when conducting a SLR for ITC comprising comparative and single-arm RWE studies.