Outcomes and costs of community health worker interventions: a systematic review.

OBJECTIVES: We conducted a systematic review on outcomes and costs of community health worker (CHW) interventions. CHWs are increasingly expected to improve health outcomes cost-effectively for the underserved. RESEARCH
DESIGN: We searched Medline, Cochrane Collaboration resources, and the Cumulative Index to Nursing and Allied Health Literature for studies conducted in the United States and published in English from 1980 through November 2008. We dually reviewed abstracts, full-text articles, data abstractions, quality ratings, and strength of evidence grades and resolved disagreements by consensus.
RESULTS: We included 53 studies on outcomes of CHW interventions and 6 on cost or cost-effectiveness. For outcomes, limited evidence (5 studies) suggests that CHW interventions can improve participant knowledge compared with alternative approaches or no intervention. We found mixed evidence for participant behavior change (22 studies) and health outcomes (27 studies). Some studies suggested that CHW interventions can result in greater improvements in participant behavior and health outcomes compared with various alternatives, but other studies suggested that CHW interventions provide no statistically different benefits than alternatives. We found low or moderate strength of evidence suggesting that CHWs can increase appropriate health care utilization for some interventions (30 studies). Six studies with economic information yielded insufficient data to evaluate the cost-effectiveness of CHW interventions relative to other interventions.
CONCLUSIONS: CHWs can improve outcomes for underserved populations for some health conditions. The effectiveness of CHWs in many health care areas requires further research that addresses the methodologic limitations of prior studies and that contributes to translating research into practice.