Analysis of socioeconomic predictors.
| Characteristics | Surgical(N = 7900) | Conservative(N = 27,299) | RR for Spine Augmentation | Adjusted P Value | |
| Unadjusted RR (95% CI) | Adjusted RR (95% CI) | ||||
| Age, y, mean (SD) | 78.5 (11.4) | 78.6 (11.4) | -- | -- | 0.543 |
| Sex, female, n (%) | 6331 (80.1) | 22,571 (82.7) | 0.88 (0.84–0.92) | 0.90 (0.87–0.94) | <0.001 |
| Race, n (%) | |||||
| White/Caucasian | 6794 (89.1) | 22,107 (85.5) | Ref | Ref | |
| Black/African American | 158 (2.1) | 711 (2.7) | 0.77 (0.67–0.89) | 0.79 (0.70–0.89) | <0.001 |
| Hispanic/Latino | 332 (4.4) | 1553 (6.0) | 0.75 (0.68–0.83) | 0.82 (0.76–0.90) | <0.001 |
| Asian/Pacific Islander | 190 (2.5) | 873 (3.4) | 0.76 (0.67–0.87) | 0.90 (0.81–0.99) | 0.048 |
| Native American | 22 (0.3) | 96 (0.4) | 0.79 (0.54–1.16) | 0.91 (0.67–1.23) | 0.518 |
| Unknown/other | 132 (1.7) | 521 (2.0) | 0.86 (0.74–1.00) | 0.88 (0.78–0.99) | 0.037 |
| Insurance coverage, n (%) | |||||
| Medicare | 6993 (88.6) | 23,739 (87.0) | Ref | Ref | |
| Medicaid | 138 (1.7) | 895 (3.3) | 0.59 (0.50–0.69) | 0.76 (0.66–0.87) | <0.001 |
| Private insurance | 663 (8.4) | 2188 (8.0) | 1.02 (0.95–1.10) | 1.06 (1.00–1.12) | 0.042 |
| Self-pay | 41 (0.5) | 184 (0.7) | 0.80 (0.61–1.06) | 0.99 (0.79–1.23) | 0.901 |
| No charge | 3 (0.0) | 17 (0.1) | 0.66 (0.23–1.87) | 0.60 (0.23–1.54) | 0.204 |
| Other | 55 (0.7) | 248 (0.9) | 0.80 (0.63–1.01) | 0.91 (0.75–1.10) | 0.311 |
| Income quartile, n (%) | |||||
| First (poorest) | 1734 (22.2) | 5835 (21.7) | Ref | Ref | |
| Second | 2065 (26.5) | 7002 (26.1) | 0.99 (0.94–1.05) | 0.98 (0.94–1.02) | 0.367 |
| Third | 2079 (26.7) | 7042 (26.2) | 0.99 (0.94–1.05) | 0.97 (0.92–1.00) | 0.248 |
| Fourth (wealthiest) | 1916 (24.6) | 6992 (26.0) | 0.94 (0.89–0.99) | 0.95 (0.91–0.99) | 0.031 |
| Hospital location/teaching status, n (%) | |||||
| Rural | 486 (6.1) | 3421 (12.5) | Ref | Ref | |
| Urban, nonteaching | 2886 (36.5) | 9230 (33.8) | 1.91 (1.75–2.09) | 1.56 (1.45–1.69) | <0.001 |
| Urban, teaching | 4528 (57.3) | 14,648 (53.7) | 1.90 (1.74–2.07) | 1.59 (1.47–1.72) | <0.001 |
| Hospital control, n (%) | |||||
| Public | 428 (5.4) | 2553 (9.4) | Ref | Ref | |
| Private, nonprofit | 6418 (81.2) | 21,903 (80.2) | 1.58 (1.44–1.73) | 1.35 (1.26–1.47) | <0.001 |
| Private, for-profit | 1054 (13.3) | 2843 (10.4) | 1.88 (1.70–2.09) | 1.51 (1.39–1.65) | <0.001 |
| Geographical region, n (%) | |||||
| Northeast | 1189 (15.1) | 6051 (22.2) | Ref | Ref | |
| Midwest | 2735 (34.6) | 6739 (24.7) | 1.76 (1.65–1.87) | 1.52 (1.44–1.60) | <0.001 |
| South | 2983 (37.8) | 7444 (27.3) | 1.74 (1.64–1.85) | 1.49 (1.42–1.57) | <0.001 |
| West | 993 (12.6) | 7065 (25.9) | 0.75 (0.69 to 0.81) | 0.90 (0.84 to 0.96) | <0.001 |
Boldface indicates statistically significant findings.