Table 5 Multivariable-adjusted associations between potential explanatory factors and return-to-work status post road traffic injury
Outcome variables | Multivariate adjusted relative risk (95%CI) | ||||||
|---|---|---|---|---|---|---|---|
Baseline | 6-months | 12-months | 24-months | ||||
Full duties RTW | Any RTW | Full duties RTW | Any RTW | Full duties RTW | Any RTW | Full duties RTW | |
Sociodemographic | |||||||
 Age (years) | |||||||
  45–59 | 1.00 (ref)†| 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  17–24 | 1.17 (0.92–1.49) | 0.89* (0.82–0.97) | 0.94 (0.83–1.05) | 0.96 (0.89–1.03) | 1.03 (0.93–1.15) | 0.94 (0.84–1.05) | 1.02 (0.90–1.15) |
  25–44 | 1.14 (0.95–1.37) | 0.99 (0.95–1.04) | 1.01 (0.94–1.08) | 0.98 (0.94–1.03) | 1.04 (0.97–1.11) | 1.03 (0.98–1.08) | 1.05 (0.97–1.13) |
  60–69 | 1.17 (0.82–1.67) | 0.93 (0.84–1.04) | 0.86 (0.71–1.04) | 0.94 (0.84–1.05) | 0.96 (0.81–1.13) | 0.92 (0.81–1.04) | 0.79* (0.63–0.98) |
  ≥ 70 | 0.46 (0.12–1.74) | 0.82 (0.59–1.13) | 0.76 (0.47–1.22) | 0.85 (0.64–1.13) | 0.68 (0.41–1.12) | 0.92 (0.72–1.19) | 0.71 (0.44–1.15) |
 Sex | |||||||
  Female | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Male | 0.92 (0.78–1.08) | 1.05 (1.00–1.11) | 1.15* (1.07–1.25) | 1.05 (0.99–1.10) | 1.05 (0.97–1.12) | 1.07* (1.00–1.13) | 1.12 (1.03–1.22) |
 Education | |||||||
  Tertiary/university | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Technical/other | 0.70*** (0.57–0.85) | 0.97 (0.92–1.02) | 0.93 (0.86–1.01) | 1.01 (0.96–1.06) | 0.98 (0.91–1.06) | 0.98 (0.93–1.04) | 1.04 (0.96–1.12) |
  Secondary | 0.72** (0.59–0.87) | 0.90** (0.85–0.96) | 0.90 (0.82–0.98) | 0.96 (0.90–1.01) | 0.92 (0.85–1.01) | 0.91* (0.84–0.98) | 0.91 (0.83–1.01) |
  Primary/pre-primary | 0.66 (0.42–1.04) | 0.91 (0.79–1.06) | 0.93 (0.77–1.13) | 0.81 (0.64–1.03) | 0.83 (0.61–1.13) | 1.07 (0.93–1.24) | 1.00 (0.79–1.25) |
 Language | |||||||
  English | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Non English | 0.71 (0.51–0.98) | 0.95 (0.87–1.05) | 0.76* (0.65–0.91) | 0.96 (0.87–1.06) | 0.80 (0.68–0.94) | 0.99 (0.90–1.08) | 0.79 (0.65–0.95) |
 Marital status |  |  |  |  |  |  |  |
  Married/defacto | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Divorced/widowed/separated | 0.86 (0.61–1.22) | 0.97 (0.89–1.06) | 0.96 (0.84–1.10) | 0.97 (0.88–1.07) | 1.04 (0.90–1.20) | 0.98 (0.88–1.08) | 0.94 (0.79–1.11) |
  Never married | 1.06 (0.90–1.24) | 0.95 (0.91–1.00) | 0.95 (0.89–1.02) | 0.97 (0.92–1.02) | 0.97 (0.91–1.05) | 0.96 (0.91–1.02) | 0.99 (0.92–1.07) |
 Occupation |  |  |  |  |  |  |  |
  Professional | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Clerical/admin services | 1.03 (0.80–1.34) | 0.90 (0.81–1.00) | 0.93 (0.81–1.08) | 1.01 (0.94–1.09) | 1.00 (0.89–1.14) | 1.02 (0.93–1.12) | 1.04 (0.90–1.20) |
  Technical/trades services | 0.50*** (0.38–0.66) | 0.98 (0.92–1.04) | 0.90 (0.81–1.00) | 1.00 (0.94–1.06) | 0.94 (0.85–1.04) | 1.06 (0.99–1.13) | 1.05 (0.96–1.16) |
  Manager | 0.91 (0.73–1.13) | 1.04 (0.99–1.09) | 1.09** (1.01–1.17) | 1.02 (0.97–1.08) | 1.02 (0.94–1.11) | 1.02 (0.95–1.10) | 1.05 (0.95–1.15) |
  Community/personal services | 0.78 (0.58–1.05) | 0.95 (0.86–1.04) | 0.96 (0.85–1.10) | 0.91 (0.81–1.01) | 0.92 (0.80–1.06) | 1.00 (0.89–1.12) | 1.05 (0.91–1.20) |
  Labourer | 0.42*** (0.24–0.71) | 0.79** (0.67–0.94) | 0.81 (0.66–1.00) | 0.83* (0.71–0.98) | 0.88 (0.72–1.08) | 1.03 (0.88–1.20) | 1.16 (0.98–1.37) |
  Sales worker | 0.68 (0.47–0.99) | 0.91 (0.80–1.02) | 0.91 (0.77–1.07) | 0.97 (0.87–1.08) | 0.97 (0.83–1.12) | 0.94 (0.82–1.08) | 0.97 (0.82–1.15) |
  Machinery operator/driver | 0.69 (0.47–1.02) | 0.92 (0.82–1.03) | 1.00 (0.85–1.17) | 0.92 (0.81–1.04) | 0.99 (0.83–1.17) | 1.02 (0.87–1.19) | 0.85 (0.66–1.10) |
 Gross yearly income (AUD) |  |  |  |  |  |  |  |
  ≥ $104,000 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  $65,000-$103,999 | 1.02 (0.83–1.25) | 0.98 (0.93–1.03) | 0.97 (0.91–1.05) | 1.00 (0.95–1.05) | 0.95 (0.88–1.02) | 1.02 (0.97–1.08) | 1.06 (0.98–1.15) |
  $41,600-$64,999 | 0.87 (0.69–1.08) | 0.94 (0.89–0.99) | 0.90 (0.82–0.99) | 0.96 (0.91–1.02) | 0.96 (0.88–1.05) | 0.97 (0.92–1.04) | 1.06 (0.96–1.16) |
  $20,800-$41,599 | 0.80 (0.60–1.05) | 0.97 (0.91–1.04) | 0.92 (0.81–1.03) | 1.02 (0.95–1.08) | 0.96 (0.86–1.07) | 0.96 (0.87–1.07) | 0.95 (0.82–1.10) |
  $0-$20,799 | 1.13 (0.80–1.61) | 0.68*** (0.56–0.83) | 0.72 (0.57–0.90) | 0.77** (0.65–0.92) | 0.70 (0.55–0.89) | 0.81* (0.68–0.97) | 0.84 (0.67–1.06) |
 Social satisfaction |  |  |  |  |  |  |  |
  Satisfied | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Neither | 0.75 (0.52–1.10) | 0.99 (0.89–1.09) | 1.11 (0.98–1.25) | 0.95 (0.86–1.06) | 0.88 (0.75–1.04) | 0.98 (0.86–1.12) | 1.01 (0.87–1.18) |
  Dissatisfied | 0.88 (0.52–1.50) | 1.01 (0.88–1.17) | 0.94 (0.76–1.17) | 0.96 (0.82–1.12) | 0.96 (0.78–1.18) | 0.98 (0.82–1.16) | 1.00 (0.78–1.27) |
Pre-injury health | |||||||
 EQ-5D-3L | |||||||
  > 0.9 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  > 0.8–0.9 | 1.33 (1.01–1.75) | 0.99 (0.91–1.08) | 1.04 (0.92–1.17) | 0.95 (0.87–1.05) | 0.96 (0.84–1.11) | 0.94 (0.83–1.06) | 0.91 (0.78–1.07) |
   ≤ 0.8 | 1.08 (0.89–1.31) | 0.94 (0.88–1.00) | 0.94 (0.86–1.04) | 0.91** (0.85–0.97) | 0.94 (0.85–1.03) | 0.97 (0.90–1.04) | 1.00 (0.91–1.10) |
 No. comorbidities | |||||||
  None | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  1 | 1.02 (0.85–1.21) | 0.96 (0.91–1.01) | 0.96 (0.90–1.03) | 0.97 (0.92–1.02) | 0.94 (0.88–1.01) | 0.97 (0.92–1.03) | 0.94 (0.87–1.01) |
  2–3 | 0.88 (0.71–1.10) | 0.91** (0.85–0.98) | 0.86 (0.78–0.96) | 0.91** (0.85–0.97) | 0.88 (0.80–0.97) | 0.91* (0.84–0.98) | 0.85 (0.76–0.94) |
   ≥ 4 | 1.00 (0.66–1.52) | 1.01 (0.91–1.12) | 0.96 (0.79–1.16) | 0.98 (0.89–1.10) | 0.83 (0.66–1.04) | 0.95 (0.83–1.08) | 0.84 (0.67–1.03) |
BMI (kg/m2) | |||||||
   < 30 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
   ≥ 30 (obese) | 0.96 (0.78–1.18) | 0.99 (0.93–1.05) | 1.01 (0.93–1.10) | 0.99 (0.94–1.05) | 0.97 (0.88–1.06) | 1.00 (0.93–1.06) | 0.99 (0.90–1.09) |
Injury-related factors | |||||||
 Crash type | |||||||
  Car (driver) | 1.00 (ref)†| 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Car (passenger) | 0.87 (0.65–1.16) | 0.89 (0.78–1.01) | 0.83 (0.70–0.99) | 0.98 (0.88–1.10) | 0.97 (0.82–1.14) | 0.95 (0.83–1.09) | 0.95 (0.80–1.12) |
  Motorbike | 0.65*** (0.54–0.79) | 1.03 (0.97–1.08) | 1.06 (0.98–1.16) | 1.02 (0.97–1.08) | 1.10** (1.01–1.20) | 1.02 (0.96–1.09) | 1.09 (0.99–1.20) |
  Bicyclist | 0.99 (0.82–1.19) | 1.05 (0.99–1.11) | 1.04 (0.96–1.13) | 1.06* (1.00–1.12) | 1.02 (0.93–1.12) | 1.09** (1.02–1.15) | 1.06 (0.97–1.16) |
  Pedestrian/skateboard | 0.68* (0.49–0.95) | 0.94 (0.84–1.05) | 0.82 (0.69–0.97) | 0.97 (0.86–1.08) | 0.88 (0.74–1.05) | 0.91 (0.78–1.05) | 0.83 (0.68–1.02) |
 Hospital admission | |||||||
  No | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Yes | 0.31*** (0.26–0.38) | 0.92*** (0.88–0.96) | 0.87 (0.82–0.93) | 0.95 (0.91–0.99) | 0.93 (0.88–1.00) | 0.98 (0.93–1.03) | 0.96 (0.90–1.03) |
Recruitment source site | |||||||
  (Hospital) Sydney metropolitan | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  (Hospital) Regional | 0.46*** (0.33–0.64) | 1.04 (0.98–1.11) | 1.10 (0.98–1.22) | 1.03 (0.97–1.10) | 1.09 (0.97–1.22) | 1.06 (1.00–1.14) | 1.19* (1.06–1.34) |
  (Hospital) Other | 0.81* (0.66–0.98) | 0.97 (0.91–1.03) | 0.97 (0.88–1.07) | 1.00 (0.94–1.06) | 1.02 (0.93–1.12) | 0.96 (0.89–1.04) | 1.04 (0.94–1.15) |
  Physio/GP/online/databases | 0.76 (0.53–1.10) | 1.07 (0.99–1.14) | 0.94 (0.79–1.11) | 1.07 (1.00–1.15) | 1.05 (0.90–1.22) | 1.02 (0.92–1.14) | 0.96 (0.80–1.15) |
 Hospital length of stay (days) | |||||||
   ≤ 1 or no presentation to hospital | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  2–6 | 0.33*** (0.25–0.44) | 0.98 (0.93–1.03) | 0.93 (0.86–1.00) | 0.97 (0.92–1.02) | 0.95 (0.88–1.02) | 0.97 (0.91–1.03) | 0.93 (0.86–1.01) |
   ≥ 7 | 0.02*** (0.00–0.14) | 0.77*** (0.67–0.88) | 0.65*** (0.53–0.79) | 0.89 (0.80–0.99) | 0.77 (0.64–0.93) | 0.94 (0.84–1.06) | 0.90 (0.76–1.05) |
Injury Severity Score | |||||||
  1–3 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  4–8 | 0.40*** (0.33–0.48) | 0.98 (0.94–1.02) | 0.93* (0.88–1.00) | 0.96 (0.92–1.01) | 0.93* (0.87–1.00) | 0.97 (0.92–1.02) | 0.99 (0.92–1.07) |
  9–11 | 0.19*** (0.10–0.36) | 0.93 (0.84–1.03) | 0.83* (0.71–0.98) | 0.98 (0.90–1.06) | 0.92 (0.80–1.07) | 0.95 (0.86–1.05) | 0.94 (0.80–1.10) |
   ≥ 12 |  < 0.001*** | 0.74** (0.60–0.92) | 0.62** (0.46–0.83) | 0.83 (0.69–1.00) | 0.65** (0.49–0.86) | 0.86 (0.72–1.03) | 0.77* (0.60–0.99) |
 Perceived danger of death | |||||||
  None | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Small | 1.03 (0.86–1.23) | 1.00 (0.95–1.05) | 0.98 (0.91–1.06) | 1.03 (0.98–1.08) | 1.05 (0.98–1.13) | 1.05 (0.99–1.11) | 1.06 (0.98–1.15) |
  Moderate | 0.74 (0.59–0.93) | 0.97 (0.92–1.03) | 0.99 (0.90–1.07) | 0.98 (0.93–1.04) | 1.07 (0.98–1.16) | 0.99 (0.92–1.06) | 1.06 (0.96–1.17) |
  Great | 0.67* (0.52–0.87) | 0.89** (0.82–0.96) | 0.93 (0.84–1.03) | 0.89* (0.81–0.97) | 0.90 (0.80–1.02) | 0.98 (0.90–1.07) | 0.98 (0.87–1.11) |
  Overwhelming | 0.70 (0.50–0.97) | 0.93 (0.85–1.03) | 0.85 (0.73–0.99) | 0.99 (0.91–1.07) | 0.93 (0.79–1.09) | 0.95 (0.85–1.05) | 0.92 (0.79–1.08) |
Insurance claim | |||||||
  No | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Yes | 0.27*** (0.19–0.38) | 0.90*** (0.84–0.95) | 0.76*** (0.68–0.84) | 0.96 (0.91–1.02) | 0.87** (0.79–0.96) | 0.91** (0.85–0.97) | 0.84** (0.76–0.93) |
Post-injury psychological and physical health status | |||||||
 IES-R | |||||||
  Normal (< 4.5) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Elevated post-traumatic stress (≥ 4.5) | 0.83 (0.68–1.01) | 0.95 (0.90–1.00) | 1.11* (1.01–1.22) | 0.96 (0.91–1.02) | 1.10 (1.00–1.22) | 0.96 (0.90–1.03) | 1.11 (1.00–1.24) |
 DASS-21 | |||||||
  ≤ 15 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Probable major depressive disorder (≥ 15) | 0.66*** (0.53–0.81) | 0.90** (0.85–0.96) | 0.96 (0.86–1.06) | 0.90** (0.84–0.96) | 0.94 (0.84–1.05) | 0.90** (0.84–0.97) | 0.98 (0.88–1.10) |
 Pain severity (NRS) | |||||||
  No pain (0) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  Mild (1–3) | 0.67*** (0.58–0.78) | 1.00 (0.94–1.06) | 1.08 (1.00–1.18) | 1.01 (0.96–1.06) | 1.05 (0.97–1.13) | 1.04 (0.97–1.11) | 1.09* (1.01–1.19) |
  Moderate-severe (4–10) | 0.37*** (0.31–0.44) | 0.95 (0.90–1.01) | 1.07 (0.98–1.17) | 0.95 (0.90–1.00) | 1.03 (0.95–1.11) | 0.95 (0.88–1.01) | 1.04 (0.95–1.14) |
 OMPSQ-SF | |||||||
   < 50 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  High risk (≥ 50) | 0.26*** (0.17–0.40) | 0.87*** (0.81–0.94) | 0.81** (0.70–0.93) | 0.92* (0.85–0.99) | 0.82** (0.70–0.95) | 0.90* (0.83–0.98) | 0.92 (0.79–1.06) |
 PCS | |||||||
   < 30 | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
  High pain-related catastrophic thinking (≥ 30) | 0.52*** (0.35–0.76) | 0.85** (0.76–0.94) | 0.96 (0.81–1.14) | 0.95 (0.87–1.05) | 0.99 (0.83–1.19) | 0.85** (0.75–0.96) | 0.98 (0.81–1.18) |