Do community health worker interventions improve rates of screening mammography in the United States? A systematic review.

BACKGROUND Community health workers (CHW) are lay individuals who are trained to serve as liaisons between members of their communities and health care providers and services. METHODS A systematic review was conducted to synthesize evidence from all prospective controlled studies on effectiveness of CHW programs in improving screening mammography rates. Studies reported in English and conducted in the United States were included if they: (i) evaluated a CHW intervention designed to increase screening mammography rates in women 40 years of age or older without a history of breast cancer; (ii) were a randomized controlled trial (RCT), case-controlled study, or quasi-experimental study; and (iii) evaluated a CHW intervention outside of a hospital setting. RESULTS Participation in a CHW intervention was associated with a statistically significant increase in receipt of screening mammography [risk ratio (RR): 1.06 (favoring intervention); 95% CI: 1.02-1.11, P = 0.003]. The effect remained when pooled data from only RCTs were included in meta-analysis (RR: 1.07; 95% CI: 1.03-1.12, P = 0.0005) but was not present using pooled data from only quasi-experimental studies (RR: 1.03; 95% CI: 0.89-1.18, P = 0.71). In RCTs, participants recruited from medical settings (RR: 1.41; 95% CI: 1.09-1.82, P = 0.008), programs conducted in urban settings (RR: 1.23; 95% CI: 1.09, 1.39, P = 0.001), and programs where CHWs were matched to intervention participants on race or ethnicity (RR: 1.58, 95% CI: 1.29-1.93, P = 0.0001) showed stronger effects on increasing mammography screening rates. CONCLUSIONS CHW interventions are effective for increasing screening mammography in certain settings and populations. IMPACT CHW interventions are especially associated with improvements in rate of screening mammography in medical settings, urban settings, and in participants who are racially or ethnically concordant with the CHW.