Summary of findings table: physical functioning outcomes as per Oswestry Disability Index (ODI) for patients with chronic pain following spinal cord stimulation
| Outcomes | Post-SCS ODI Weighted Mean (SD) | Baseline SCS ODI Weighted Mean (SD) | Mean difference (95% CI) | No of participants (studies) | Quality or certainty of the evidence (GRADE) | Comments |
| 3-month ODI Scores | 50.66 (13.17) | 30.89 (16.15) | −19.90 (−28.24 to 11.57) | 12 Studies (eight observational studies, 4 RCT) | ⊕〇〇〇 Very low | Two RCTs had high risk of bias in DS (Risk of bias from period and carryover effects). One RCT with some concerns of bias from bias in selection of the reported results. High clinical (variable patients’ characteristics, severity of chronic pain conditions, SCS settings, geographical location and practices), methodological, and statistical heterogeneity (I2 95%). Publication bias is suspected. |
| 6-month ODI Scores | 45.98 (11.52) | 34.79 (14.13) | −11.20 (−14.85 to 7.55) | 15 Studies (10 observational studies, 5 RCT) | ⊕〇〇〇 Very low | One RCT with high risk of bias, two with some concerns and one with low risk of bias. High clinical (variable patients’ characteristics, severity of chronic pain conditions, SCS settings, geographic location and practices), methodological, and statistical heterogeneity (I2 81%). Publication bias is suspected. |
| 12-month ODI Scores | 50.24 (12.19) | 33.24 (15.52) | −17.00 (−23.07 to 10.94) | 17 Studies (14 observational studies, 3 RCT) | ⊕〇〇〇 Very low | One RCT with high risk of bias and one with some concerns of bias. High clinical (variable patients’ characteristics, severity of chronic pain conditions, SCS settings, geographical location and practices), methodological, and statistical heterogeneity (I2 96%). Possibility of small study effects based on Funnel plot asymmetry. |
| 24-month ODI Scores | 56.21 (6.51) | 39.10 (9.96) | −17.11 (−20.88 to 13.34) | three observational studies | ⊕〇〇〇 Very low | The observational studies had a high risk of bias in the NOS categories of ‘selection’, ‘comparability of cohorts’, and ‘assessment of outcome’. High heterogeneity (I2 56%). |
Population: Adult patients with chronic pain indications including non-surgical or postsurgical back pain.
Intervention: Spinal cord stimulation.
Comparator: Comparing patient outcomes compared to their baseline status.
DS, Risk of bias from period and carryover effects; GRADE, Grading of Recommendations Assessment, Development and Evaluation; NOS, Newcastle-Ottawa scale; RCTs, randomised controlled trials; SCS, spinal cord stimulation.