Education, referrals, support and other interventions by community health workers improve rates of screening mammography in the United States – especially in medical and urban settings and among women whose race and ethnicity is similar to that of the community health workers serving them.

Researchers at the University of South Florida, Moffitt Cancer Center, and Georgia Southern University reported these findings earlier this month in an online first issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research. Their systematic review and analysis of a wide range of original studies evaluating community health worker programs offers a clearer, more powerful picture of the effectiveness of CHWs than the single studies alone – some which found no improvement in mammography screening.

Community health workers (CHW) are lay people trained to serve as a bridge between people in their communities and health care providers and services. CHWs have traditionally served people who lack access to adequate health care and are at highest risk for poor outcomes. These liaisons have often been used to promote screenings for breast cancer, a disease with significant racial and socioeconomic disparities in mortality, survival rates and cancer stage at diagnosis.

"Our systematic study points to the fact that community health workers play an important role in helping medically underserved women obtain screening mammograms," said lead author Kristen Wells, PhD, MPH, assistant professor at the USF Center for Evidence-Based Medicine and Health Outcomes Research. "Future studies need to focus on what factors really drive the success of the interventions. What makes a strong community health worker program that best helps the most people?"

The researchers systematically reviewed 24 studies (randomized controlled trials, case-controlled studies and quasi-experimental studies) investigating the effectiveness of CHW programs specifically designed to increase screening mammography in women age 40 or older without a history of breast cancer. These programs were conducted in the United States in community health clinics or other settings outside a hospital. Eighteen studies enrolled a total of 26,660 participants and provided enough data to do further analysis.

Overall, the analysis found that interventions by CHWs are associated with a significant increase in rates of screening mammography. The study also teased out from the randomized controlled trials some new findings about when and where CHW programs are most likely to benefit:

  • Studies that reported matching CHWs and patient populations by race and ethnicity showed stronger improvement in adhering to mammography guidelines than those that did not.
  • Recruiting participants from a medical setting, like a community clinic, was more effective than recruiting them from churches, neighborhoods or other community settings. "A link to a medical setting is critical when designing a community health worker program to promote mammography screening," Wells said.
  • CHW interventions offered in urban settings were associated with increases in screening mammography, while those provided in rural locales were not. "This difference may reflect accessibility issues and transportation barriers," Wells said. "In some rural communities, mammograms are more difficult to obtain."
  • CHW programs that reported delivering three or more types of interventions -- including health education, referrals, appointment scheduling, vouchers, free or low-cost mammograms, emotional or social support, appointment reminders – were associated with stronger increases in screening mammography than programs providing two or less types.