Can health information and decision aids decrease inequity in health care? A systematic review on the equality of their effectiveness

ObjectivesSystematic review of studies evaluating evidence-based health information (EBHI) and decision aids (DAs) in terms of the extent to which inequity-producing factors have been considered and how these factors affect access to health-related information and informed decision-making. Study designSystematic review of randomised controlled trials. MethodsSystematic searches were performed in the Cochrane Library, PubMed, Embase, PsycINFO, CINAHL, ERIC and PSYNDEX from inception to May 2023 to identify evaluation studies of EBHI and DAs that take into account factors associated with unequal opportunities as defined by PROGRESS Plus. Information on the effect of these factors was extracted and analysed in terms of outcomes relevant to the decision-making process. ResultsFew studies have examined the impact of EBHI/DAs on outcomes relevant to decision-making with respect to inequity-producing factors. In our final synthesis,12 studies were included. A positive association between the effectiveness of the intervention and the disadvantage status could be found twice and a negative association in three studies. Overall, most of the studies found no difference in knowledge gain, decision conflict and shared decision-making (SDM) between those advantaged and disadvantaged in terms of ethnicity, gender, education, age, income, health literacy, numeracy or socioeconomic status (SES). However, few trials examined this effect and the effect was considered solely in subgroup analyses that were probably underpowered, so asymmetries between these groups may not have been detected in the existing designs. ConclusionEBHI and DAs have been shown to be effective in promoting decision-making and thus in improving health care. To improve health care equitably, greater attention needs to be paid to methodological requirements in evaluations to fully capture potential differences in access to health-related information between individuals or in populations within the target groups of EBHI/DAs. PROSPERO registrationCRD42018103456 What is already known?O_LIThere is evidence that EBHI and DAs do not reach certain patient groups because while being developed and evaluated they do not adequately take into account differences in access to health-related information between different social groups. C_LIO_LIThere is insufficient evidence whether EBHI and DAs are equally effective for people with factors that are more or less associated with equal access to health information. C_LI What the study addsO_LIA systematic review of evaluation studies of EBHI and DAs to consider factors that lead to inequity and analysis of how these factors influence the intervention effects in terms of access to health-related information and outcomes relevant for decision-making. C_LI How this study might affect research, practice or policy?O_LIOur research makes a valuable contribution to more equitable health care by stressing critical inequality factors that may influence informed decision-making with the help of EBHI and DAs. C_LI