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Table 2 Characteristics of patients with low back pain and of patients who also have leg pain or signs of nerve root involvement

From: Patients with low back pain differ from those who also have leg pain or signs of nerve root involvement – a cross-sectional study

 

All subgroups

Local LBP only

LBP + pain above knee

LBP + pain below knee

LBP + signs of nerve root involvement

p-values

 

n = 2,673

n = 437

n = 398

n = 807

n = 1,031

Significant pair-wise comparisons

Females, (95% CI)

56% (54%-58%)

49% (44%-54%)

59% (54%-64%)

60% (57%-64%)

54% (51%-57%)

p < .01 local vs. above local vs. below below vs. NRI

Age in years, median (IQR)

47 (36-58)

43 (32-55)

46 (35-58)

50 (39-63)

46 (37-58)

p < .001 local vs. all below vs. all

Duration*, (95% CI) 0 – 3 months

18% (16%-19%)

8% (6%-11%)

13% (10%-16%)

15% (12%-17%)

27% (24%-29%)

p < .001 local vs. below NRI vs. all

3 – 12 months

34% (32%-36%)

34% (30%-39%)

36% (31%-41%)

35% (31%-38%)

35% (32%-38%)

 

> 12 months

45% (44%-47%)

57% (53%-62%)

51% (46%-56%)

51% (47%-54%)

38% (35%-41%)

 

Previous episodes, (95% CI)

74% (73%-76%)

67% (62%-71%)

77% (72%-80%)

76% (72%-79%)

79% (76%-81%)

p < .01 local vs. all

Pain irritability, (95% CI)

74% (72%-76%)

60% (53%-66%)

73% (67%-78%)

76% (72%-80%)

79% (75%-82%)

p < .001 local vs. all

LBP intensity, median (IQR)

6 (5-8)

5 (4-7)

6 (4-7)

6 (4-8)

6 (5-8)

p < .001 all comparisons except above vs. below

Leg pain intensity, median (IQR)

3 (5-7)

0 (0-0)

4 (3-6)

6 (4-7)

6 (5-8)

p < .001 all comparisons

Severe leg pain, (95% CI)

70% (68%-72%)

0 (0-0)

68% (64%-73%)

85% (82%-87%)

88% (86%-90%)

p < .001 all comparisons

Dominating leg pain, (95% CI)

29% (27%-31%)

0 (0-0)

23% (18%-27%)

36% (32%-39%)

38% (35%-41%)

p < .001 all comparisons except NRI vs. below

Activity limitation, median (IQR)

65 (43-83)

48 (26-67)

57 (39-74)

65 (43-78)

74 (52-87)

p < .001 all comparisons

Regular employment § (95% CI)

66% (64%-68%)

77% (73%-82%)

65% (60%-71%)

62% (58%-66%)

66% (63%-70%)

p = .01 local vs. all

Any sick leave in last 3 months # , (95% CI)

49% (46%-51%)

41% (35%-47%)

44% (36%-52%)

47% (41%-52%)

56% (52%-61%)

P <.001 NRI vs. all

Sick leave days in last three months # , median (IQR)

14 (5 – 30)

10 (4 – 25)

10 (5 – 21)

14 (5 – 34)

18 (7-34)

< .01 local vs. below local vs. NRI

Depressive symptoms, (95% CI)

17% (16%-19%)

12% (9%-15%)

16% (12%-19%)

16% (14%-19%)

21% (18%-23%)

p < .001 local vs. below NRI vs. all

Fear of movement, (95% CI)

19% (18%-21%)

15% (12%-19%)

16% (12%-19%)

18% (16%-22%)

23% (20%-25%)

P=.06 NRI vs. all

General health, median (IQR)

50 (30-70)

53 (40-75)

50 (33-70)

50 (30-67)

48 (29-64)

p < .001 local vs. all above vs. NRI

Directional preference, ¤ (95% CI)

36% (33%-39%)

19% (13%-25%)

32% (24%-39%)

31% (26%-37%)

49% (44%-54%)

p < .001 all comparisons except above vs. below

  1. 95% CI = 95% confidence interval; IQR = inter quartile range; NRI = Nerve root involvement signs.
  2. *Does not sum to 100% because of missing values.
  3. #Proportion of patients in regular employment.
  4. ¤Proportion of patients with a test conclusion n=1,012(38%)/159(36%)/168(42%)/283(35%)/402(39%.)