Table 1 Baseline characteristics of the included and the not-included patients in the 4-year follow-up study
Baseline variables a | Included | Not included b | ||
|---|---|---|---|---|
| Â | Missing values, n (%) | Â | Missing values, n (%) | Â |
Contextual factors | Â | Â | Â | Â |
Age (years), median (IQR) | 0 (0) | 33.1 (27.5–37.4)* | 0 (0) | 31.8 (25.7–36.3)* |
Sex (female) | 0 (0) | 54 (49.4–57.6) | 0 (0) | 54 (49.6–58.7) |
Normal weight (BMI) | 25 (4) | 44 (40.0-48.4) | 88 (18.8) | 47 (41.9–52.0) |
Pain-related factors | Â | Â | Â | Â |
Pain intensity (NRS), median (IQR) | 0 (0) | 6 (4.7–7.3) | 59 (12.6) | 6.3 (5.0-7.3) |
Episode duration (months), median (IQR) | 17 (3) | 10.1 (3.7–35.6) | 65 (13.9) | 11.1 (3.8–44.8) |
Previous LBP episodes | 11 (1.9) | 77 (73.8–80.7)* | 68 (14.6) | 70 (65.7–74.7)* |
Leg pain | 7 (1.2) | 83 (80.0-86.2)* | 66 (14.1) | 77 (73.2–81.4)* |
Pain in other parts | 13 (2.3) | 42 (37.7–45.9) | 68 (14.6) | 40 (34.8–44.4) |
Activity limitation restricted factors | ||||
Disability (RMDQ), median (IQR) | 0 (0) | 56.5 (39.1–73.9) | 76 (16.3) | 56.5 (39.1–73.9) |
Psychological factors | ||||
Depression | 11 (1.9) | 22 (18.2–25.1) | 84 (18) | 23 (18.7–27.2) |
Anxiety | 8 (1.4) | 45 (40.7–48.6) | 83 (17.8) | 44.5 (39.5–49.5) |
Fear-avoidance | 7 (1.2) | 21 (17.92–24.7) | 75 (16.1) | 26 (21.9–30.7) |
Risk of persistent pain | 8 (1.4) | 46 (41.95–50.2) | 83 (17.8) | 45 (40.3–50.3) |
Social isolation | 8 (1.4) | 12 (9.4–14.8) | 83 (17.8) | 14 (10.8–17.8) |
Participation restricted related factors | ||||
Regular employment or studying | 14 (2.5) | 71 (66.7–74.3) | 74 (15.8) | 33 (28.7–38.0) |
Sick leave | 46 (8) | 50 (45.5–54.1) | 97 (20.8) | 51 (45.7–55.9) |