Do interventions designed to support shared decision-making reduce health inequalities? A systematic review and meta-analysis

PLoS One. 2014 Apr 15;9(4):e94670. doi: 10.1371/journal.pone.0094670. eCollection 2014.


Background: Increasing patient engagement in healthcare has become a health policy priority. However, there has been concern that promoting supported shared decision-making could increase health inequalities.

Objective: To evaluate the impact of SDM interventions on disadvantaged groups and health inequalities.

Design: Systematic review and meta-analysis of randomised controlled trials and observational studies.

Data sources: CINAHL, the Cochrane Register of Controlled Trials, the Cochrane Database of Systematic Reviews, EMBASE, HMIC, MEDLINE, the NHS Economic Evaluation Database, Open SIGLE, PsycINFO and Web of Knowledge were searched from inception until June 2012.

Study eligibility criteria: We included all studies, without language restriction, that met the following two criteria: (1) assess the effect of shared decision-making interventions on disadvantaged groups and/or health inequalities, (2) include at least 50% of people from disadvantaged groups, except if a separate analysis was conducted for this group.

Results: We included 19 studies and pooled 10 in a meta-analysis. The meta-analyses showed a moderate positive effect of shared decision-making interventions on disadvantaged patients. The narrative synthesis suggested that, overall, SDM interventions increased knowledge, informed choice, participation in decision-making, decision self-efficacy, preference for collaborative decision making and reduced decisional conflict among disadvantaged patients. Further, 7 out of 19 studies compared the intervention's effect between high and low literacy groups. Overall, SDM interventions seemed to benefit disadvantaged groups (e.g. lower literacy) more than those with higher literacy, education and socioeconomic status. Interventions that were tailored to disadvantaged groups' needs appeared most effective.

Conclusion: Results indicate that shared decision-making interventions significantly improve outcomes for disadvantaged patients. According to the narrative synthesis, SDM interventions may be more beneficial to disadvantaged groups than higher literacy/socioeconomic status patients. However, given the small sample sizes and variety in the intervention types, study design and quality, those findings should be interpreted with caution.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review
  • Systematic Review

MeSH terms

  • Decision Making*
  • Delivery of Health Care / methods*
  • Delivery of Health Care / statistics & numerical data
  • Guideline Adherence
  • Health Knowledge, Attitudes, Practice
  • Humans
  • Socioeconomic Factors

Grants and funding

This systematic review was supported by a small grant from the East and North Hertfordshire NHS Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.