A systematic review and meta-analysis of effectiveness of decision aids for vaccination decision-making.

Background: This systematic review and meta-analysis aimed to assess the effectiveness of vaccination decision aids compared with usual care on vaccine uptake, vaccine attitudes, decisional conflict, intent to vaccinate and timeliness.

Methods: Searches were conducted in OVID Medline, OVID Embase, CINAHL, PsycINFO, the Cochrane Library and SCOPUS. Randomised controlled trials were included if they evaluated the impact of decision aids as defined by the International Patient Decision Aids Standards Collaboration. Where possible, meta-analysis was undertaken. Where meta-analysis was not possible, we conducted a narrative synthesis. Risk of bias in included trials was assessed using the Cochrane Collaboration's risk of bias tool. Data were analysed using STATA.

Results: Five RCTs were identified that evaluated the effectiveness of decision aids in the context of vaccination decision making. Meta-analysis of four studies showed that decision aids may have slightly increased vaccination uptake, but this was reduced to no effect once studies with higher risk of bias were excluded. Meta-analysis of three studies showed that decision aids moderately increased intention to vaccinate. Narrative synthesis of two studies suggested that decision aids reduced decisional conflict. One study reported that decision aids decreased perceived risk of vaccination. Content, format and delivery method of the decision aids varied across the studies. It was not clear from the information reported whether these variations affected the effectiveness of the decision aids.

Conclusion: Decision aids can assist in vaccine decision making. Future studies of decision aids could provide greater detail of the decision aids themselves, which would enable comparison of the effectiveness of different elements and formats. Standardising decision aids would also allow for easier comparison between decision aids.