Randomized controlled trial of mammography intervention in insured very low-income women.

BACKGROUND The expectation that insurance coverage mitigates health disparities and equalizes use of healthcare assumes that services are equally accessed; however, the insured low-income target population in this research had a mammography rate of 23.4%, well below the general population. Our objective was to determine the most effective intervention to improve mammography use in low-income women insured by a managed care organization (MCO). METHODS The study was a randomized controlled trial. Participants were 2,357 women noncompliant with screening mammography randomly assigned to one of three groups: control (n = 786) received usual care; simple intervention (n = 785) received prompt letter from the MCO medical director; and stepwise intervention (n = 786) received the same prompt letter from the MCO; if noncompliant, a second prompt letter from their primary care physician and, if still noncompliant, counseling from lay health workers. Outcome was completion of screening mammography extracted from medical records. RESULTS Screening rates were 13.4% for the control, 16.1% for the simple intervention, and 27.1% for the stepwise intervention. Compared with the control, the primary care physician letter in the stepwise intervention increased the likelihood of screening by 80% [Relative Risk (RR) = 1.80; P < 0.001], and counseling tripled the likelihood of screening (RR = 3.11; P < 0.001). CONCLUSIONS Compared with the control and simple intervention, a stepwise intervention to increase mammography is effective in a target population of hard-to-reach, low-income, insured women. IMPACT The research provides evidence for the impact of stepwise interventions to improve cancer screening in low-income insured populations, although the screening rates remain well below those of the general population.