Table 2

The effects of mTBI on labour market attachment in subgroups of premorbid characteristics: demographics, comorbidities and psychological illness, up to 5 years postinjury

Controls
(n=18 640)*
mTBI
(n=19 732)*
Crude OR
(95% CI)
P valueAdjusted OR
(95% CI)†
P value
Age (years)
 18–29
  6 months3420 (41.80)3647 (41.76)1.16 (1.10 to 1.23)<0.00011.19 (1.12 to 1.26)<0.0001
  5 years3160 (38.62)3870 (44.31)1.47 (1.36 to 1.59)<0.00011.56 (1.43 to 1.71)<0.0001
 30–39
  6 months798 (19.33)1471 (34.29)1.23 (1.13 to 1.35)<0.00011.31 (1.18 to 1.46)<0.0001
  5 years666 (16.13)1562 (36.41)1.68 (1.50 to 1.89)<0.00011.93 (1.68 to 2.23)<0.0001
 40–49
  6 months462 (13.38)1192 (32.63)1.15 (1.03 to 1.28)0.01231.26 (1.11 to 1.42)0.0003
  5 years577 (16.71)1406 (38.49)1.14 (1.00 to 1.30)0.0492)1.27 (1.10 to 1.48)0.0014
 50–60
  6 months427 (14.85)979 (32.05)1.41 (1.28 to 1.56)<0.00011.54 (1.37 to 1.73)<0.0001
  5 years1117 (38.84)1582 (51.78)0.89 (0.78 to 1.02)0.09020.93 (0.80 to 1.08)0.3541
Gender
 Male
  6 months2536 (22.51)4034 (33.98)1.24 (1.18 to 1.30)<0.00011.30 (1.22 to 1.37)<0.0001
  5 years2860 (25.39)4735 (39.88)1.36 (1.28 to 1.46)<0.00011.48 (1.36 to 1.60)<0.0001
 Female
  6 months2571 (34.87)3255 (41.41)1.25 (1.18 to 1.32)<0.00011.31 (1.23 to 1.40)<0.0001
  5 years2660 (36.07)3685 (46.88)1.48 (1.37 to 1.60)<0.00011.62 (1.48 to 1.77)<0.0001
Education
 Low education
  6 months2524 (36.31)3899 (43.56)1.19 (1.12 to 1.26)<0.00011.21 (1.13 to 1.29)<0.0001
  5 years2968 (42.69)4648 (51.93)1.27 (1.18 to 1.37)<0.00011.32 (1.20 to 1.43)<0.0001
 Medium education
  6 months1978 (24.78)2511 (33.64)1.33 (1.25 to 1.40)<0.00011.41 (1.32 to 1.51)<0.0001
  5 years1947 (24.39)2731 (36.59)1.54 (1.42 to 1.68)<0.00011.70 (1.54 to 1.88)<0.0001
 High education
  6 months519 (14.97)678 (22.73)1.40 (1.24 to 1.57)<0.00011.51 (1.31 to 1.74)<0.0001
  5 years494 (14.25)813 (27.25)1.87 (1.60 to 2.19)<0.00012.15 (1.78 to 2.59)<0.0001
Cohabitation status
 Single
  6 months2006 (35.24)3607 (44.80)1.32 (1.25 to 1.38)<0.00011.38 (1.30 to 1.46)<0.0001
  5 years1973 (34.66)4037 (50.14)1.44 (1.35 to 1.54)<0.00011.54 (1.43 to 1.66)<0.0001
 Married or cohabiting couple
  6 months3095 (24.01)3672 (31.48)1.17 (1.10 to 1.24)<0.00011.21 (1.13 to 1.30)<0.0001
  5 years3532 (27.39)4376 (37.51)1.49 (1.37 to 1.62)<0.00011.64 (1.48 to 1.81)<0.0001
Ethnicity
 Danish born
  6 months4730 (26.79)6767 (36.17)1.24 (1.19 to 1.29)<0.00011.30 (1.24 to 1.36)<0.0001
  5 years5146 (29.14)7825 (41.82)1.40 (1.33 to 1.47)<0.00011.52 (1.43 to 1.62)<0.0001
 Not Danish born
  6 months371 (40.06)512 (50.84)1.30 (1.12 to 1.52)0.00081.34 (1.11 to 1.61)0.0024
  5 years359 (38.77)588 (58.39)1.86 (1.51 to 2.31)<0.00011.98 (1.52 to 2.57)<0.0001
Comorbidities
 No comorbidity
  6 months4832 (27.05)6750 (36.33)1.24 (1.19 to 1.29)<0.00011.29 (1.24 to 1.35)<0.0001
  5 years5205 (29.14)7758 (41.75)1.40 (1.33 to 1.48)<0.00011.52 (1.43 to 1.62)<0.0001
 >1 comorbidity
  6 months275 (35.39)315 (40.54)1.31 (1.13 to 1.51)0.00041.38 (1.15 to 1.66)0.0006
  5 years539 (46.79)662 (57.47)1.61 (1.30 to 2.00)<0.00011.81 (1.38 to 2.37)<0.0001
Psychiatric diagnosis‡
 No diagnosis
  6 months4981 (27.15)6561 (35.39)1.26 (1.21 to 1.30)<0.00011.31 (1.26 to 1.37)<0.0001
  5 years5368 (29.26)7600 (40.99)1.43 (1.36 to 1.51)<0.00011.56 (1.46 to 1.65)<0.0001
 >1 diagnosis
  6 months126 (42.71)728 (61.07)1.14 (0.90 to 1.43)0.27801.16 (0.89 to 1.51)0.2868
  5 years152 (51.53)820 (68.79)1.12 (0.83 to 1.51)0.44961.12 (0.79 to 1.60)0.5266
  • *Top row indicates total numbers of included patients and controls in the study. Column numbers and percentages indicate each subgroup experiencing the outcome.

  • †ORs adjusted for ethnicity, municipality, calendar year, seasonal variation, comorbidities, psychiatric illness, age and gender of not attending ordinary work for patients with mTBI in comparison to the control group.

  • ‡Psychiatric diagnosis in secondary care 5 years prior to the index date (1 January 1998–31 December 2002).

  • mTBI, mild traumatic brain injury.