Behavioral Interventions to Improve Breast Cancer Screening Outreach: Two Randomized Clinical Trials

Despite public health efforts, breast cancer screening rates remain below national goals.

To evaluate whether bulk ordering, text messaging, and clinician endorsement increase breast cancer screening rates.

Two concurrent, pragmatic, randomized clinical trials, each with a 2-by-2 factorial design, were conducted between October 25, 2021, and April 25, 2022, in 2 primary care regions of an academic health system. The trials included women aged 40 to 74 years with at least 1 primary care visit in the past 2 years who were eligible for breast cancer screening.

Patients in trial A were randomized in a 1:1 ratio to receive a signed bulk order for mammogram or no order; in a factorial design, patients were concurrently randomized in a 1:1 ratio to receive or not receive text message reminders. Patients in trial B were randomized in a 1:1 ratio to receive a message signed by their primary care clinician (clinician endorsement) or from the organization (standard messaging); in a factorial design, patients were concurrently randomized in a 1:1 ratio to receive or not receive text message reminders.

The primary outcome was the proportion of patients who completed a screening mammogram within 3 months.

Among 24 632 patients included, the mean (SD) age was 60.4 (7.5) years. In trial A, at 3 months, 15.4% (95% CI, 14.6%-16.1%) of patients in the bulk order arm and 12.7% (95% CI, 12.1%-13.4%) in the no order arm completed a mammogram, showing a significant increase (absolute difference, 2.7%; 95% CI, 1.6%-3.6%; P < .001). In the text messaging comparison arms, 15.1% (95% CI, 14.3%-15.8%) of patients receiving a text message completed a mammogram compared with 13.0% (95% CI, 12.4%-13.7%) of those in the no text messaging arm, a significant increase (absolute difference of 2.1%; 95% CI, 1.0%-3.0%; P < .001). In trial B, at 3 months, 12.5% (95% CI, 11.3%-13.7%) of patients in the clinician endorsement arm completed a mammogram compared with 11.4% (95% CI, 10.3%-12.5%) of those in the standard messaging arm, which was not significant (absolute difference, 1.1%; 95% CI, -0.5% to 2.7%; P = .18). In the text messaging comparison arms, 13.2% (95% CI, 12.0%-14.4%) of patients receiving a text message completed a mammogram compared with 10.7% (95% CI, 9.7%-11.8%) of those in the no text messaging arm, a significant increase (absolute difference, 2.5%; 95% CI, 0.8%-4.0%; P = .003).

These findings show that text messaging women after initial breast cancer screening outreach via either electronic portal or mailings, as well as bulk ordering with or without text messaging, can increase mammogram completion rates.

ClinicalTrials.gov Identifier: NCT05089903.