Table 2.
Use of Imaging Within 4 Weeks of the Initial Visit for Patients with Acute Low Back Pain, by Patient Characteristics
| Patient characteristics | Number of patients | Received radiography | Received CT/MRI | ||
|---|---|---|---|---|---|
| Percentage (%) | Adjusted OR (95 % CI)* | Percentage (%) | Adjusted OR (95 % CI)* | ||
| All | 145,320 | 23.55 | 8.10 | ||
| Age (years) | |||||
| 66–69 | 37,517 | 21.33 | Reference | 8.49 | Reference |
| 70–74 | 37,807 | 22.47 | 1.08 (1.04–1.12) | 8.36 | 0.96 (0.91–1.01) |
| 75–79 | 30,336 | 24.54 | 1.22 (1.17–1.27) | 8.58 | 0.98 (0.92–1.03) |
| 80–84 | 22,448 | 25.77 | 1.31 (1.26–1.37) | 7.86 | 0.87 (0.82–0.93) |
| ≥ 85 | 17,212 | 26.15 | 1.34 (1.28–1.41) | 6.14 | 0.67 (0.62–0.72) |
| Sex | |||||
| Female | 95,004 | 23.81 | Reference | 7.80 | Reference |
| Male | 50,316 | 23.07 | 0.98 (0.95–1.01) | 8.65 | 1.11 (1.07–1.16) |
| Race | |||||
| Non-Hispanic white | 102,448 | 24.33 | Reference | 8.93 | Reference |
| Non-Hispanic black | 9132 | 21.46 | 0.91 (0.86–0.97) | 6.08 | 0.76 (0.69–0.83) |
| Hispanic | 28,875 | 22.61 | 1.02 (0.97–1.07) | 6.37 | 0.82 (0.77–0.89) |
| Other/unknown | 4865 | 16.59 | 1.01 (0.91–1.11) | 4.50 | 0.75 (0.64–0.87) |
| Comorbidity score | |||||
| 0 | 86,300 | 23.80 | Reference | 8.31 | Reference |
| 1 | 35,076 | 23.24 | 1.00 (0.97–1.03) | 8.10 | 0.97 (0.92–1.02) |
| 2 | 13,185 | 23.62 | 1.02 (0.97–1.07) | 7.69 | 0.96 (0.90–1.04) |
| ≥3 | 10,759 | 22.50 | 0.98 (0.93–1.04) | 6.87 | 0.85 (0.78–0.93) |
| Percentage of patients in ZIP Code area with high school education | |||||
| Q1 (≤72 %) | 38,103 | 23.79 | Reference | 6.96 | Reference |
| Q2 (73–81 %) | 37,129 | 23.65 | 1.02 (0.97–1.07) | 8.71 | 1.03 (0.96–1.10) |
| Q3 (82–89 %) | 35,040 | 23.82 | 1.01 (0.96–1.06) | 8.45 | 1.02 (0.95–1.09) |
| Q4 (≥90 %) | 35,048 | 23.05 | 1.03 (0.98–1.08) | 8.26 | 1.02 (0.95–1.09) |
| Medicaid eligibility | |||||
| Yes | 27,511 | 21.02 | Reference | 5.62 | Reference |
| No | 117,809 | 24.14 | 1.05 (1.00–1.09) | 8.67 | 1.27 (1.19–1.36) |
| Urban/Rural | |||||
| Rural | 2224 | 21.22 | Reference | 8.05 | Reference |
| Metro | 114,580 | 23.66 | 1.12 (0.99–1.27) | 7.79 | 0.96 (0.81–1.15) |
| Non-metro | 28,516 | 23.31 | 1.07 (0.94–1.21) | 9.32 | 1.11 (0.93–1.33) |
| Number of physician visits in prior year | |||||
| 0 | 26,967 | 24.83 | Reference | 7.59 | Reference |
| 1 | 18,269 | 24.04 | 0.92 (0.88–0.97) | 7.75 | 1.03 (0.95–1.11) |
| 2 | 20,629 | 24.25 | 0.95 (0.91–1.00) | 8.25 | 1.11 (1.03–1.20) |
| 3 or more | 79,455 | 22.83 | 0.89 (0.85–0.93) | 8.31 | 1.20 (1.13–1.27) |
*Estimated from a multilevel model with patient characteristics but without specific physician characteristics. The multilevel model adjusted for the clustering of patients within providers