Baseline Characteristics of Participants
| Total (n = 447) | UC (n = 115) | SPLIT (n = 332) | P Value | |
|---|---|---|---|---|
| Sociodemographic | ||||
| Age, y, mean (SD) | 46.19 (11.65) | 48.06 (11.41) | 45.46 (11.75) | .035a |
| Female, No. (%) | 268 (60.0) | 65 (56.5) | 203 (61.1) | .383b |
| BMI (kg/m2), No. (%) | .872b | |||
| Underweight or normal weight, | 174 (39.4) | 46 (40.0) | 128 (39.1) | |
| Overweight or obesity | 268 (60.6) | 69 (60.0) | 199 (60.9) | |
| Marital status, No. (%) | .937b | |||
| Lives alone | 158 (35.3) | 41 (35.7) | 117 (35.2) | |
| Lives with someone | 289 (64.7) | 74 (64.3) | 215 (64.8) | |
| Years of education, No. (%) | .365b | |||
| 0-9 | 216 (48.5) | 60 (52.2) | 156 (47.3) | |
| ≥10 | 229 (51.5) | 55 (47.8) | 174 (52.7) | |
| Work status, No. (%) | .068b | |||
| Active | 314 (70.7) | 89 (77.4) | 225 (68.4) | |
| Not working | 130 (29.3) | 26 (22.6) | 104 (31.6) | |
| Clinical | ||||
| Duration of LBP episode, No. (%) | .618b | |||
| <12 weeks | 231 (51.9) | 62 (53.9) | 169 (51.2) | |
| ≥12 weeks | 214 (48.1) | 53 (46.1) | 161 (48.8) | |
| Referred leg pain, No. (%) | 206 (46.5) | 76 (66.1) | 130 (39.6) | ≤.001b |
| LBP pain medication, No. (%) | 225 (51.1) | 66 (57.4) | 159 (48.9) | .118b |
| Sickness certificate, No. (%) | 95 (21.6) | 31 (27.0) | 64 (19.7) | .104b |
| SBST risk subgroup, No. (%) | ≤.001b | |||
| Low | 174 (38.9) | 20 (17.4) | 154 (46.4) | |
| Medium | 189 (42.3) | 62 (53.9) | 127 (38.3) | |
| High | 84 (18.8) | 33 (28.7) | 51 (15.4) | |
| SBST psychosocial subscale (Q5-9, 0-5), mean (SD) | 2.20 (1.45) | 2.78 (1.28) | 2.00 (1.45) | ≤.001a |
| Back-related disability (RMDQ, 0-24), mean (SD) | 9.46 (6.18) | 12.63 (5.90) | 8.37 (5.89) | ≤.001a |
| Pain intensity (NPRS, 0-10), mean (SD) | 4.23 (2.61) | 5.41 (2.56) | 3.83 (2.50) | ≤.001a |
| HRQoL (EQ-5D-3L, 0-1), mean (SD) | 0.56 (0.25) | 0.44 (0.23) | 0.61 (0.25) | ≤.001a |
BMI = body mass index; EQ-5D-3L = EuroQoL 5 dimensions 3 levels; HRQoL = health-related quality of life; LBP = low back pain; NPRS = Numeric Pain Rating Scale; Q5-9 = Questions 5-9; RMDQ = Roland-Morris Disability Questionnaire; SBST = STarT Back Screening Tool; SPLIT = stratified primary care for low back pain; UC = usual care.
Note: Sample size was not consistent, owing to missing data. Total: BMI (n = 442); years of education (n = 445); work status (n = 444); duration of LBP episode (n = 445); referred leg pain (n = 443); pain medication (n = 440); sickness certificate (n = 440). SPLIT: BMI (n = 327); years of education (n = 330); work status (n = 329); duration of LBP episode (n = 330); referred leg pain (n = 328); pain medication (n = 325); sickness certificate (n = 325).
↵a Mann-Whitney test.
↵b χ2 test.