Two controlled trials to determine the effectiveness of a mailed intervention to increase colon cancer screening.

OBJECTIVE: Colorectal cancer (CRC) screening is underutilized. Effective and efficient interventions are needed to increase its utilization in primary care.
METHODS: We used UNC Internal Medicine electronic medical records to perform 2 effectiveness trials. Eligible patients had no documentation of recent CRC screening and were aged 50-75 years. The mailed intervention contained a letter documenting the need for screening signed by the attending physician in wave A and the practice director in wave B, a postcard to request a decision aid about CRC screening options, and information about how to obtain screening. RESULT: Three-hundred and forty patients of attending physicians in wave A, 944 patients of resident physicians in wave B, and 214 patients of attending physicians in wave B were included. The intervention increased screening compared with controls for attending physicians' patients in wave A (13.1% vs. 4.1%, 95% CI, 3.1%-14.9%) but not for resident physicians' patients in wave B (1.3% vs. 1.9%, 95% CI, -2.2% to 1.0%). A small increase in screening with the intervention was seen in attending physicians' patients in wave B (6.9% vs. 2.4%, 95% CI, -1.4% to 10.5%). Requests for decision aids were uncommon in both waves (12.5% wave A and 7.8% wave B). LIMITATIONS: The group assignments were not individually randomized, and covariate information to explain the differences in effect was limited.
CONCLUSIONS: The intervention increased CRC screening in attending physicians' patients who received a letter from their physicians, but not resident physicians' patients who received a letter signed by the practice director.