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 |