Table 2.
Predictive validity of DOT-transformed SFS categories for non-return to work at 1, 3, 6, and 12 months of follow-up
| DOT categories (SFS score adapted) | N-RTW | RTW | Sens | Spec | +PV | Lr+ | N-RTW | RTW | Sens | Spec | +PV | Lr+ |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| WC-Cut-off: 0–49 % | WC-Cut-off: 50–100 % | WC-Cut-off: 0–99 % | WC-Cut-off: 100 % | |||||||||
| 1 month follow-up | ||||||||||||
| Minimal (0–99) | 55 | 12 | 0.37 | 0.92 | 0.82 | 4.64 | 62 | 5 | 0.28 | 0.94 | 0.93 | 4.32 |
| Sedentary (100–124) | 26 | 19 | 0.54 | 0.80 | 0.72 | 2.65 | 41 | 4 | 0.46 | 0.88 | 0.92 | 3.99 |
| Light (125–164) | 43 | 66 | 0.83 | 0.36 | 0.56 | 1.30 | 72 | 37 | 0.78 | 0.41 | 0.79 | 1.32 |
| Medium (165–179) | 13 | 26 | 0.91 | 0.19 | 0.53 | 1.13 | 25 | 14 | 0.89 | 0.23 | 0.77 | 1.16 |
| Heavy (180–194) | 9 | 20 | 0.97 | 0.06 | 0.51 | 1.03 | 19 | 10 | 0.98 | 0.10 | 0.76 | 1.09 |
| Very heavy (195–200) | 4 | 9 | 5 | 8 | ||||||||
| 3 months follow-up | ||||||||||||
| Minimal (0–99) | 43 | 24 | 0.41 | 0.88 | 0.64 | 3.41 | 56 | 11 | 0.32 | 0.91 | 0.84 | 3.69 |
| Sedentary (100–124) | 17 | 28 | 0.58 | 0.74 | 0.54 | 2.20 | 29 | 16 | 0.49 | 0.79 | 0.81 | 2.28 |
| Light (125–164) | 33 | 76 | 0.89 | 0.35 | 0.42 | 1.38 | 55 | 54 | 0.80 | 0.36 | 0.67 | 1.25 |
| Medium (165–179) | 6 | 33 | 0.95 | 0.19 | 0.39 | 1.17 | 17 | 22 | 0.90 | 0.19 | 0.64 | 1.11 |
| Heavy (180–194) | 3 | 26 | 0.98 | 0.06 | 0.35 | 1.04 | 14 | 15 | 0.98 | 0.07 | 0.59 | 1.05 |
| Very heavy (195–200) | 2 | 11 | 4 | 9 | ||||||||
| 6 months follow-up | ||||||||||||
| Minimal (0–99) | 28 | 39 | 0.38 | 0.83 | 0.42 | 2.25 | 45 | 22 | 0.34 | 0.87 | 0.67 | 2.67 |
| Sedentary (100–124) | 12 | 33 | 0.55 | 0.69 | 0.36 | 1.74 | 21 | 24 | 0.50 | 0.73 | 0.59 | 1.87 |
| Light (125–164) | 26 | 83 | 0.90 | 0.32 | 0.30 | 1.34 | 42 | 67 | 0.82 | 0.34 | 0.49 | 1.25 |
| Medium (165–179) | 4 | 35 | 0.96 | 0.17 | 0.27 | 1.16 | 8 | 31 | 0.66 | 0.16 | 0.45 | 0.79 |
| Heavy (180–194) | 1 | 28 | 0.97 | 0.05 | 0.25 | 1.02 | 10 | 19 | 0.96 | 0.05 | 0.44 | 1.01 |
| Very heavy (195–200) | 2 | 11 | 5 | 8 | ||||||||
| 12 months follow-up | ||||||||||||
| Minimal (0–99) | 15 | 52 | 0.37 | 0.80 | 0.22 | 1.84 | 21 | 46 | 0.33 | 0.81 | 0.31 | 1.73 |
| Sedentary (100–124) | 6 | 39 | 0.51 | 0.65 | 0.19 | 1.47 | 10 | 35 | 0.49 | 0.66 | 0.28 | 1.45 |
| Light (125–164) | 13 | 96 | 0.83 | 0.28 | 0.15 | 1.16 | 19 | 90 | 0.79 | 0.28 | 0.23 | 1.11 |
| Medium (165–179) | 4 | 35 | 0.93 | 0.15 | 0.15 | 1.09 | 5 | 34 | 0.87 | 0.14 | 0.21 | 1.02 |
| Heavy (180–194) | 0 | 29 | 0.93 | 0.04 | 0.13 | 0.96 | 5 | 24 | 0.95 | 0.04 | 0.21 | 0.99 |
| Very heavy (195–200) | 3 | 10 | 3 | 10 | ||||||||
N-RTW not return to work based on the WC, RTW return to work based on the WC, Spec specificity, Sens sensitivity, +PV positive predictive value, Lr+ likelihood ratio of a positive test, DOT Dictionary of Occupational Titles, SFS Spinal Function Sort