TABLE III.
Treatment Choice Logistic Regression Model Results
| Surgery | Physical Therapy | Watchful Waiting | |
| Model covariables* | |||
| Clinical characteristics | |||
| Age group (ref: 66-69 yr) | |||
| 70-75 yr | 0.88 (0.82, 0.93)† | 1.12 (1.06, 1.18)† | 0.99 (0.93, 1.04) |
| 76-79 yr | 0.66 (0.60, 0.72)† | 1.20 (1.11, 1.28)† | 1.11 (1.04, 1.19)‡ |
| 80-85 yr | 0.42 (0.38, 0.47)† | 1.29 (1.20, 1.39)† | 1.28 (1.19, 1.38)† |
| ≥86 yr | 0.28 (0.23, 0.35)† | 1.19 (1.05, 1.35)‡ | 1.57 (1.39, 1.78)† |
| Charlson comorbidity index (ref: 0) | |||
| 1 | 0.94 (0.87, 1.01)§ | 0.94 (0.88, 1.00)# | 1.12 (1.05, 1.19)† |
| 2 | 0.90 (0.82, 0.98)# | 1.00 (0.94, 1.08) | 1.08 (1.00, 1.16)# |
| 3 | 0.85 (0.77, 0.95)‡ | 0.93 (0.85, 1.01)§ | 1.21 (1.11, 1.31)† |
| ≥4 | 0.73 (0.66, 0.82)† | 0.94 (0.87, 1.02) | 1.28 (1.18, 1.39)† |
| Frailty index (ref: 0) | |||
| 1 | 0.96 (0.90, 1.03) | 1.00 (0.94, 1.05) | 1.03 (0.98, 1.09) |
| 2 | 0.90 (0.80, 1.01)§ | 0.96 (0.87, 1.05) | 1.12 (1.02, 1.22)# |
| ≥3 | 0.78 (0.65, 0.94)‡ | 0.90 (0.79, 1.02) | 1.25 (1.10, 1.42)† |
| Cane | 0.79 (0.47, 1.32) | 0.92 (0.67, 1.26) | 1.20 (0.88, 1.64) |
| Walker | 1.07 (0.87, 1.31) | 0.91 (0.78, 1.06) | 1.07 (0.92, 1.24) |
| Wheelchair | 0.76 (0.51, 1.12) | 0.77 (0.60, 1.00)# | 1.42 (1.11, 1.82)‡ |
| Pre-365 Medicare reimbursements | |||
| $1,400 to $3,229 | 0.94 (0.87, 1.01)§ | 1.18 (1.10, 1.26)† | 0.90 (0.84, 0.96)‡ |
| $3,230 to $7,369 | 0.85 (0.79, 0.93)† | 1.28 (1.19, 1.37)† | 0.88 (0.82, 0.94)† |
| $7,370 to $621,000 | 0.84 (0.76, 0.92)† | 1.20 (1.11, 1.30)† | 0.95 (0.87, 1.02) |
| Prior physical therapy use (ref: 0) | |||
| 1-4 d | 0.71 (0.60, 0.84)† | 1.93 (1.72, 2.17)† | 0.60 (0.52, 0.68)† |
| 5-9 d | 0.74 (0.62, 0.88)† | 1.85 (1.63, 2.10)† | 0.61 (0.53, 0.70)† |
| 10-19 d | 0.66 (0.55, 0.79)† | 2.11 (1.86, 2.41)† | 0.56 (0.48, 0.65)† |
| ≥20 d | 0.47 (0.34, 0.66)† | 3.03 (2.48, 3.72)† | 0.42 (0.34, 0.53)† |
| Demographics | |||
| Male | 1.30 (1.23, 1.38)† | 0.76 (0.73, 0.80)† | 1.10 (1.05, 1.16)† |
| Race (ref: white) | |||
| Black | 0.78 (0.67, 0.91)‡ | 0.81 (0.73, 0.91)† | 1.41 (1.26, 1.57)† |
| Hispanic | 0.61 (0.44, 0.87)‡ | 1.02 (0.82, 1.26) | 1.23 (0.99, 1.52)§ |
| Asian | 0.50 (0.33, 0.76)‡ | 1.51 (1.17, 1.94)‡ | 0.92 (0.72, 1.19) |
| Other | 0.87 (0.69, 1.10) | 1.02 (0.85, 1.23) | 1.08 (0.90, 1.30) |
| Medicaid dual-eligible | 0.70 (0.61, 0.81)† | 0.63 (0.57, 0.69)† | 1.86 (1.69, 2.04)† |
| Model summary and fit statistics | |||
| No. of patients | 32,203 | 32,203 | 32,203 |
| Model R2 | |||
| McFadden | 0.03 | 0.02 | 0.02 |
| Tjur | 0.03 | 0.03 | 0.02 |
| Log likelihood | |||
| Null | −16,041.27 | −21,835.36 | −21,510.82 |
| Model | −15,529.97 | −21,389.15 | −21,117.93 |
| Wald chi-square | |||
| Clinical and demographic | 901.64 | 841.98 | 732.95 |
| Demographic | 166.64 | 216.74 | 250.58 |
| Clinical | 675.10 | 578.91 | 432.92 |
*
The values are given as the odds ratio, with the 95% CI in parentheses.
†
P < 0.001.
‡
P < 0.01.
§
P < 0.1.
#
P < 0.05.