Baseline characteristics
| Variable | Usual care (n=27) | Internet intervention plus usual care (n=29) | Internet intervention plus physiotherapist support (n=27) |
| Female | 15 (55.6%) | 19 (65.2%) | 17 (63.0%) |
| Age | 60.3 (16.3) | 54.5 (13.7) | 59.3 (10.4) |
| Marital status | |||
| Married/partner | 23 (85.2%) | 19 (65.5%) | 22 (81.5%) |
| Single | 3 (11.1%) | 4 (13.8%) | 2 (7.4%) |
| Divorced/separated | 0 | 5 (17.2%) | 1 (3.7%) |
| Widow/widower | 1 (3.6%) | 1 (3.6%) | 2 (7.4%) |
| White ethnicity | 27 (100%) | 26 (92.9%) | 27 (100%) |
| Age left education | 17.6 (2.7) | 17.3 (1.7) | 17.6 (2.8) |
| Employment status | |||
| Full time | 7 (25.9%) | 12 (41.8%) | 6 (22.2%) |
| Part time | 2 (7.4%) | 4 (13.8%) | 8 (29.6%) |
| Retired | 13 (48.2%) | 6 (20.7%) | 8 (29.6%) |
| Self-employed | 2 (7.4%) | 3 (10.3%) | 4 (14.8%) |
| Sickness/disability | 2 (7.4%) | 2 (6.9%) | 1 (3.7%) |
| Other | 1 (3.7%) | 2 (6.9%) | 0 |
| Annual income (up to £) | |||
| 10 000 | 2 (7.4%) | 4 (14.3%) | 3 (11.5%) |
| 20 000 | 7 (25.9%) | 6 (21.4%) | 3 (11.5%) |
| 40 000 | 9 (33.3%) | 9 (32.1%) | 10 (38.5%) |
| >40 000 | 9 (33.3%) | 9 (32.1%) | 10 (38.5%) |
| Expected reimprovement in LBP | 5.86 (1.88) | 5.22 (2.06) | 5.74 (2.19) |
| Expected percentage improvement in LBP (item from the CEQ) | 43.21% (25.53) | 41.92% (21.17) | 37.40% (25.50) |
| Median days of pain in the last 4 weeks (IQR) (item from the CEQ) | 10 (6, 25) | 10 (4, 21) | 18 (5, 28) |
| Time since you had a whole month without pain | |||
| <3 months | 5 (17.2%) | 6 (21.4%) | 5 (19.2%) |
| 3–6 months | 1 (3.5%) | 2 (7.1%) | 4 (15.4%) |
| 7–12 months | 5 (17.2%) | 4 (14.3%) | 6 (23.1%) |
| 1–2 years | 7 (24.1%) | 4 (14.3%) | 5 (19.2%) |
| 3–5 years | 4 (13.8%) | 4 (14.3%) | 3 (11.5%) |
| 6–10 years | 2 (6.9%) | 4 (14.3%) | 3 (11.5%) |
| >10 years | 5 (17.2%) | 4 (14.3%) | 0 |
| LBP-related disability (RMDQ) mean (SD) | 6.8 (4.9) | 6.6 (4.6) | 7.7 (4.7) |
| STarT Back risk group | |||
| Low | 16 (57.1%) | 19 (67.9%) | 14 (51.9%) |
| Medium | 11 (39.3%) | 6 (21.4%) | 12 (44.4%) |
| High | 1 (3.8%) | 3 (10.7%) | 1 (3.7%) |
CEQ, Credibility and Expectancy Questionnaire; LBP, low back pain; RMDQ, Roland and Morris Disability Questionnaire.