Figure 1.

Stepped-wedge allocation of trial subjects. Patients were excluded for any of the following reasons: a prior lumbar spine image within 12 months (n = 11,149; 97% of exclusions), an imaging report finalization date more than 4 days after image completion date (n = 354; 3%), an image completion date before report finalization date (n = 3), and not having a link to utilization data (n = 9). For clinics under the control condition, “Intervention” indicates that the intervention text was mistakenly included in the image report. For clinics under the intervention condition, “Intervention” indicates that the intervention text was successfully included in the image report, and “No intervention” indicates that the intervention text was not included.