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. 2022 Aug 5;22:1498. doi: 10.1186/s12889-022-13884-5

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)

†: Reference variable

Significant associations after additional p-value adjustments for all factors are indicated in bold: *p < 0.05, **p < 0.01, ***p < 0.001

RTW Return-to-work, IES-R Impact of Events Scale Revised, DASS-21 Depression and Anxiety Stress Scales, NRS Numeric Rating Scale, OMPSQ-SF Örebro Musculoskeletal Pain Screening Questionnaire Short Form, PCS Pain Catastrophizing Scale