Results:
Among the 562 patients included, the mean age was 62.1 (SD 11.1); 56.8% were male, 51.1% had Medicare, and 40.6% were Black. At 6 months, 27.6% (95% CI: 19.5–35.7) completed ultrasound in the Usual care arm, 54.5% (95% CI: 47.9–61.0) in the Letter + Order arm, and 54.1% (95% CI: 47.5–60.6) in the Letter + Order + Incentive arm. There was a significant increase in the Letter + Order arm compared to Usual care (absolute difference of 26.9%; 95% CI: 16.5–37.3; 