Table 3. The relative difference with multivariable generalized linear models for medical costs and productivity costs and multivariable cox proportional hazards model for RTW in the first two years after trauma.
| Generalized linear models | Cox proportional hazards model | ||
|---|---|---|---|
| Medical costs | Productivity costs | RTW | |
| N = 3109d | N = 939e,f | N = 1015e,g | |
| Exp(E) (95% CI) | Exp(E) (95% CI) | Hazard Ratio (95% CI) | |
| Age (years) | |||
| 18–44 | Ref | Ref | Ref |
| 45–64 | 1.16 (1.00, 1.34) | 0.96 (0.86, 1.07) | 1.08 (0.92, 1.26) |
| 65–74b | 1.25 (1.05, 1.48) | 0.62 (0.45, 0.87) | 1.48 (0.88, 2.49) |
| ≥75 | 1.77 (1.48, 2.12) | NA | NA |
| Female gender | 1.13 (1.03, 1.25) | 0.68 (0.62, 0.76) | 0.82 (0.71, 0.95) |
| Educational level | |||
| Lowa | Ref | Ref | Ref |
| Middle | 0.92 (0.82, 1.03) | 0.93 (0.82, 1.05) | 1.27 (1.06, 1.53) |
| High | 1.07 (0.94, 1.21) | 0.71 (0.62, 0.80) | 2.10 (1.74, 2.55) |
| Injury classifications | |||
| Pelvic injury | 2.01 (1.66, 2.44) | 1.18 (0.95, 1.46) | 0.84 (0.61, 1.15) |
| Hip fracture | 1.19 (0.99, 1.44) | 1.02 (0.82, 1.27) | 0.87 (0.63, 1.20) |
| Tibia, complex foot or femur fracture | 1.58 (1.34, 1.86) | 1.14 (0.98, 1.33) | 0.70 (0.56, 0.88) |
| Shoulder and upper arm injury | 1.12 (0.95, 1.32) | 1.00 (0.86, 1.17) | 0.98 (0.78, 1.23) |
| Radius. ulna or hand fracture | 1.00 (0.83, 1.21) | 1.14 (0.96, 1.36) | 0.80 (0.62, 1.02) |
| Head injury with AIS ≤ 2 | 0.86 (0.76, 0.97) | 0.87 (0.77, 0.98) | 1.04 (0.88, 1.23) |
| Head injury with AIS ≥ 3 | 1.58 (1.18, 2.12) | 1.06 (0.78, 1.46) | 0.87 (0.55, 1.39) |
| Facial injury | 1.12 (0.91, 1.38) | 0.92 (0.75, 1.11) | 0.92 (0.70, 1.22) |
| Thoracic injury | 1.07 (0.83, 1.38) | 0.93 (0.74, 1.17) | 1.09 (0.78, 1.53) |
| Rib fracture | 1.02 (0.86, 1.21) | 0.99 (0.84, 1.17) | 1.20 (0.94, 1.51) |
| Abdominal injury AIS ≤ 2 | 0.93 (0.66, 1.32) | 0.79 (0.59, 1.04) | 1.62 (1.08, 2.42) |
| Abdominal injury AIS ≥ 3 | 1.81 (1.06, 3.09) | 0.85 (0.58, 1.25) | 1.54 (0.86, 2.78) |
| Spinal cord injury | 2.62 (1.34, 5.11) | 1.28 (0.68, 2.40) | 0.66 (0.28, 1.59) |
| Stable vertebral fracture or disc injury | 1.29 (1.06, 1.57) | 1.39 (1.15, 1.67) | 0.66 (0.50, 0.87) |
| ISS | |||
| 1–3 | Ref | Ref | Ref |
| 4–8 | 1.11 (0.96, 1.29) | 1.36 (1.17, 1.57) | 0.72 (0.59, 0.89) |
| 9–15 | 1.50 (1.25, 1.80) | 1.40 (1.15, 1.70) | 0.62 (0.47, 0.82) |
| >15 | 1.89 (1.37, 2.60) | 1.27 (0.91, 1.77) | 0.67 (0.42, 1.07) |
| Length of stay at hospital (days) | NAc | ||
| 1–2 | Ref | Ref | |
| 3–7 | 1.25 (1.10, 1.43) | 0.74 (0.61, 0.89) | |
| 8–14 | 1.50 (1.24, 1.81) | 0.53 (0.40, 0.70) | |
| >14 | 1.54 (1.15, 2.08) | 0.41 (0.26, 0.65) | |
| External cause | |||
| Home and leisurea | Ref | Ref | Ref |
| Traffic | 0.97 (0.87, 1.09) | 0.97 (0.86, 1.09) | 1.03 (0.87, 1.23) |
| Occupational | 1.08 (0.86, 1.36) | 1.30 (1.08, 1.57) | 0.79 (0.60, 1.04) |
| Sport | 0.68 (0.56, 0.83) | 0.91 (0.78, 1.06) | 1.31 (1.06, 1.63) |
| Self-harm | 0.96 (0.40, 2.32) | 0.66 (0.31, 1.40) | 0.89 (0.27, 2.89) |
| Violence | 1.08 (0.69, 1.69) | 0.95 (0.65, 1.40) | 1.22 (0.69, 2.14) |
| Other | 0.95 (0.58, 1.56) | 0.88 (0.53, 1.45) | 1.41 (0.69, 2.86) |
| ICU admission | NAc | 1.27 (1.02, 1.58) | 0.82 (0.59, 1.14) |
| Number of comorbidities | |||
| 0a | Ref | Ref | Ref |
| 1 | 1.11 (0.98, 1.24) | 0.97 (0.86, 1.09) | 1.05 (0.88, 1.25) |
| ≥2 | 1.35 (1.18, 1.54) | 1.01 (0.86, 1.20) | 0.92 (0.71, 1.18) |
| Frail | 1.06 (0.91, 1.24) | NAc | NAc |
| Pre-injury health status | 0.63 (0.49, 0.82) | 0.90 (0.58, 1.40) | 1.69 (0.86, 3.31) |
| Intercept | 5102.99 (3761.04, 6923.74) | 8370.42 (5342.99, 13113.25) | NA |
| McFadden R2 | 31.50% | 19.80% | NA |
| C-statistic (95% CI) | NA | NA | 0.700 (0.682. 0.718) |
aReference category of categorical variable.
bCategory changed to 65–67 for productivity loss costs and RTW.
cvariables were not considered as predictors.
dmissing values: 23 Number of comorbidities, 389 Pre-injury health status, 264 medical costs.
eworking population N = 1236.
fmissing values: 3 Number of comorbidities, 90 Pre-injury health status, 204 missing productivity loss costs. fmissing values: 18 status RTW, 113 time to event, 87 Pre-injury health status, 3 Number of comorbidities.
Abbreviations: AIS, Abbreviated Injury Scale; CI, Confidence Interval; ISS, Injury Severity Score; NA, Not Applicable.