CDC COMMUNITY GUIDE: Cancer Prevention & Control, Client-Oriented Screening Interventions: Reducing Structural Barriers: Colorectal Cancer

Structural barriers are non-economic burdens or obstacles that make it difficult for people to access cancer screening. Interventions designed to reduce these barriers may facilitate access to cancer screening services by:
• Reducing time or distance between service delivery settings and target populations
• Modifying hours of service to meet client needs
• Offering services in alternative or non-clinical settings (e.g., mobile mammography vans at worksites or in residential communities)
• Eliminating or simplifying administrative procedures and other obstacles (e.g., scheduling assistance, patient navigators, transportation, dependent care, translation services, limiting the number of clinic visits)

The Community Preventive Services Task Force recommends interventions to reduce structural barriers to increase screening for breast and colorectal cancers (by mammography and FOBT, respectively) on the basis of strong evidence of effectiveness. Evidence is insufficient, however, to determine whether reducing structural barriers is effective in increasing colorectal cancer screening by flexible sigmoidoscopy or colonoscopy because only one study using these screening procedures were identified. Evidence is also insufficient to determine the effectiveness of the intervention in increasing screening for cervical cancer because only three relevant studies were identified, and these had some methodological limitations.

Interventions to reduce structural barriers can increase cancer screenings.

Results from the Systematic Reviews:
Breast Cancer:
Results of the Original Review
The original breast cancer screening review included seven studies.
• Mammography screening: median increase of 17.7 percentage points (interquartile interval [IQI]: 11.5 to 30.5 percentage points).

Results of the Updated Review
One additional study qualified for the updated review.
• Mammography screening: increase of 18 percentage points
Clinical breast examinations: increase of 34 percentage points

Cervical Cancer:
Three studies qualified for the review.
•Pap screening: median increase of 13.6 percentage points (range: 5.9-17.8)
•While these results were in the favorable direction, the studies had some methodological limitations.

Colorectal Cancer:
Results of the Original Review
The original colorectal cancer screening review included seven studies.
• Screening by FOBT: median increase of 16.1 percentage points (IQI: 12.1 to 22.9 percentage points)

Results of the Updated Review
Five additional studies qualified for the updated review.
•Colorectal cancer screening: median increase of 36.9 percentage points (range: 16.3 to 41.1 percentage points; 4 study arms)
•The larger intervention effect during the update period imay be at least partially due to differences in target populations, baseline rates of screening, and study designs.
•The Task Force recommendation should be applicable across a range of settings where target populations may have limited physical access to FOBT.