Do economic evaluations of TAVI consider learning effects, innovation, and context dependency? A review

Introduction
Most collectively funded healthcare systems set limits to their benefit package. Doing so requires judgements which may involve economic evaluations. Performing such evaluations brings methodological challenges, which may be more pronounced in non-pharmaceutical interventions. For example, for medical devices, the validity of assessment results may be limited by learning effects, incremental innovation of the devices and the context-dependency of their outcomes.

Objective
To review the extent to which "learning effects", "incremental innovation" (related to outcomes) and "context-dependency" are included and/or discussed in peer reviewed economic evaluations on medical devices using Transcatheter Aortic Valve Implementation (TAVI) as an example.

Methods
A systematic review was performed including full economic evaluations of TAVI for operable patients with aortic stenosis identified using the Pubmed database. Study characteristics, study results and text fragments concerning the aforementioned aspects were extracted. The quality of the studies was assessed using a quality checklist (CHEC-extended).

Results
Within 207 screened records, 15 studies were identified. Two studies referred to all three aspects, four studies referred to none. "Learning effects" were discussed in five studies, one of which described a method to cope with this challenge. “Incremental innovation” was described in seven studies. Limitations in generalizability of results related to context of care provision were discussed in seven studies.

Conclusion
The challenges related to economic evaluations of TAVI and their influence on the validity of reported results, are typically only partly discussed and rarely dealt within peer reviewed studies. It is important for better informed policy decisions that this improves.