As-treated analyses*
| Outcome | Lumbar fusion (N=62) | Cognitive/exercises (N=49) | Adjusted treatment effect (95% CI)† |
|---|---|---|---|
| Primary | |||
| Oswestry disability index‡ | |||
| Baseline | 44.4±10.6 | 43.0±11.1 | −1.6 (−8.9 to 5.6) |
| 4 Years | 29.1±20.2 | 27.7±19.9 | |
| Secondary | |||
| General function score‡ | |||
| Baseline | 37.9±19.3 | 39.2±19.2 | −3.2 (−11.4 to 5.0) |
| 4 Years | 24.8±24.7 | 22.5±22.9 | |
| Back pain‡ | |||
| Baseline | 63.3±14.7 | 64.2±12.5 | 4.1 (−4.7 to 12.8) |
| 4 Years | 40.5±23.0 | 46.8±23.4 | |
| Lower limb pain‡ | |||
| Baseline | 48.4±23.1 | 44.8±24.9 | −2.9 (−12.6 to 6.7) |
| 4 Years | 35.5±27.7 | 32.7±26.8 | |
| Emotional distress§ | |||
| Baseline | 1.8±0.5 | 1.9±0.5 | 0.1 (−0.2 to 0.3) |
| 4 Years | 1.6±0.5 | 1.6±0.7 | |
| Life satisfaction¶ | |||
| Baseline | 5.0±2.3 | 4.7±1.7 | 0.2 (−0.6 to 1.0) |
| 4 Years | 6.4±2.4 | 6.2±2.4 | |
| Fear-avoidance physical activity** | |||
| Baseline | 13.1±5.0 | 15.5±5.1 | −2.8 (−5.3 to −0.4) |
| 4 Years | 8.8±7.0 | 7.3±6.4 | |
| Fear – avoidance work** | |||
| Baseline | 26.4±10.1 | 28.1±12.4 | −4.8 (−8.9 to −0.7) |
| 4 Years | 23.8±13.0 | 21.1±13.4 | |
| Patients overall rating – no (%) success†† | |||
| 1 Year | 38 (61) | 32 (65) | 1.1 (0.8 to 1.8) |
| Work – no (%) | |||
| Baseline | 8 (13) | 9 (18) | 0.8 (0.4 to 1.6) |
| 1 Year | 15 (26) | 16 (33) | |
↵* Mean values±SD unless otherwise noted.
↵† The treatment effect is the difference between the lumbar fusion group and the cognitive intervention and exercises group at 4 years with adjustments for baseline score, age, gender and previous disc surgery. All patients randomly assigned (n=124) are included with last observed value carried forward.
↵‡ The Oswestry disability index, the general function score, back and lower limb pain ranges from 0 to 100, with lower scores indicating fewer symptoms.
↵§ Emotional stress ranges from 1 to 4, with lower scores indicating less severe symptoms.
↵¶ Life satisfaction ranges from 1 to 10, with higher scores indicating better life satisfaction.
↵** Fear-avoidance beliefs for physical activity ranges from 0 to 24 and for work from 0 to 42, with lower scores indicating less strong beliefs for physical activity and work hurting the back.
↵†† All who did not attend the 4-year follow-up are classified as non-success.