Making decisions on your own: Self-administered decision aids about colorectal cancer screening - A systematic review and meta-analyses.

Objective: To provide a systematic review of self-administered decision aids (DAs) for citizens invited to participate in colorectal cancer screening synthesizing the effectiveness of self-administered DAs on informed choice or the components hereof; knowledge, attitudes, and participation.

Methods: The literature search was undertaken in PubMed, CINAHL, PsycINFO, Embase and Scopus and last updated 19 March 2021. Results were presented by narrative synthesis, meta-analyses and vote counting based on direction of effect.

Results: Fourteen studies of fair methodological quality were included. One study reported on informed choice and 13 studies reported on the components. Self-administered DAs increased participation and knowledge whereas it was inconclusive with regard to attitudes towards screening. The studies were very heterogeneous with different comparators, outcomes and means of measurement.

Conclusion: This systematic review showed a potential for self-administered DAs to support informed choice in colorectal cancer screening, especially by increasing knowledge.

Practice Implications: It seems reasonable to consider informed choice to be one of the main outcomes of self-administered DAs. Yet there is a need for consensus on how to measure informed choice in cancer screening, especially a validated measurement of knowledge defining what constitutes 'adequate knowledge'.