Postoperative braces for degenerative lumbar diseases
Appendices
Appendix 1. MEDLINE search strategy
1. randomized controlled trial.pt.
2. controlled clinical trial.pt.
3. pragmatic clinical trial.pt.
4. comparative study.pt.
5. randomi#ed.ab.
6. placebo.ab.
7. drug therapy.fs.
8. randomly.ab.
9. trial.ab.
10. groups.ab.
11. or/1‐10
12. (animals not (humans and animals)).sh.
13. 11 not 12
14. lumbar vertebrae/
15. spinal fusion/
16. (spinal fusion or spondylodesis or spondylodeses or spondylosyndesis or spondylosyndeses).mp.
17. Intervertebral disc degeneration/
18. Intervertebral disc displacement/
19. Intervertebral disc/
20. ((disk$ or disc$) adj5 (disease$ or degenerat$ or hernia$ or displace$ or prolapse$ or degrad$ or slip$)).mp.
21. (lumb$ adj5 (degenerat$ or hernia$ or stenosis or stenoses or spine or spinal or vertebra$)).mp.
22. exp spondylosis/
23. (spondylosis or spondylolysis or spondylolyses or spondylolisthesis or spondylolistheses or spondylisthesis or spondylistheses).mp.
24. spinal stenosis/
25. spinal diseases/
26. spinal osteophytosis/
27. spinal osteophytosis.mp.
28. arthrodesis/
29. (lumb$ adj5 (arthrodesis or arthrodeses or fusion)).mp.
30. or/14‐29
31. Spinal canal/
32. limit 31 to yr=1966‐1982
33. 30 or 32
34. Orthotic Devices/
35. (orthoses or orthosis or orthesis or orthotic$).mp.
36. Braces/
37. (brace$ or bracing).mp.
38. belt$.mp.
39. corset$.mp.
40. (lumb$ adj support$).mp.
41. mechanical support$.mp.
42. casts, surgical/
43. cast?.mp.
44. Immobilization/
45. (Immobiliz$ or immobilis$).mp.
46. or/34‐45
47. Orthopedic Equipment/
48. limit 47 to yr=1966‐1971
49. 46 or 48
50. 13 and 33 and 49
Appendix 2. The GRADE approach to evidence synthesis
We will categorize the quality of the evidence as follows.
-
High: further research is very unlikely to change the confidence in the estimate of effect.
-
Moderate: further research is likely to have an important impact in the confidence in the estimate of effect.
-
Low: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
-
Very low: any estimate of effect is very uncertain.
We will grade the evidence available to answer each subquestion on the domains in the following manner.
1. Risk of bias
Limitations in the study design and implementation may bias the estimates of the treatment effect. Our confidence in the estimate of the effect and in the following recommendation decreases if studies suffer from major limitations. We will examine all studies on five types of biases.
-
Selection (random sequence generation, allocation concealment, group similarities at baseline).
-
Performance (blinding of participants, blinding of healthcare providers).
-
Attrition (drop outs and intention‐to‐treat analysis).
-
Measurement (blinding of the outcome assessors and timing of outcome assessment).
-
Reporting bias (selective reporting).
We will not downgrade evidence from studies that we consider the majority of subjects have no bias for all five categories.
We will downgrade one point when we judge the majority of subjects have three or fewer categories with bias.
We will downgrade evidence by two points when we judge the majority of subjects have four or more categories with bias.
2. Inconsistency
Inconsistency refers to an unexplained heterogeneity of results. Widely differing estimates of the treatment effect (i.e. heterogeneity or variability in results) across studies suggest true differences in underlying treatment effect. Inconsistency may arise from differences in: populations (e.g. drugs may have larger relative effects in sicker populations), interventions (e.g. larger effects with higher drug doses), or outcomes (e.g. diminishing treatment effect with time). We will downgrade the quality of the evidence as follows.
-
By one level: when the heterogeneity or variability in results is large (e.g. I2 statistic value of above 80%).
-
By two levels: when the heterogeneity or variability in results is large AND there was inconsistency arising from populations, interventions, or outcomes.
3. Indirectness
Indirect population, intervention, comparator, or outcome – the question being addressed in this systematic review is different from the available evidence regarding the population, intervention, comparator, or an outcome in the included randomized trial.
We will downgrade the quality of the evidence as follows.
-
By one level: when there is indirectness in only one area.
-
By two levels: when there is indirectness in two or more areas.
4. Imprecision
Results are imprecise when studies include relatively few participants and few events and thus have wide 95% confidence intervals (CIs) around the estimate of the effect. In this case we will judge the quality of the evidence lower than it otherwise would because of resulting uncertainty in the results. We will consider each outcome separately.
For dichotomous outcomes
We will consider imprecision for either of the following two reasons:
-
There is only one study. When there is more than one study, the total number of events is less than 300 (a threshold rule‐of‐thumb value) (Mueller 2007).
-
The95% CI around the pooled or best estimate of effect includes both 1) no effect and 2) appreciable benefit or appreciable harm. The threshold for 'appreciable benefit' or 'appreciable harm' is a relative risk reduction (RRR) or relative risk increase (RRI) greater than 25%.
We will downgrade the quality of the evidence as follows.
-
By one level: when there is imprecision due to (1) or (2).
-
By two levels: when there is imprecision due to (1) and (2).
For continuous outcomes
We will consider imprecision for either of the following two reasons.
-
There is only one study. When there is more than one study, total population size is less than 400 (a threshold rule‐of‐thumb value; using the usual α and β, and an effect size of 0.2 standard deviation (SD), representing a small effect).
-
The 95% CI includes no effect and the upper or lower confidence limit crosses an effect size (standardized mean difference) of 0.5 in either direction.
We will downgrade the quality of the evidence as follows.
-
By one level: when there is imprecision due to (1) or (2).
-
By two levels: when there is imprecision due to (1) and (2).
5. Publication bias
Publication bias is a systematic underestimate or an overestimate of the underlying beneficial or harmful effect due to the selective publication of studies. We will downgrade the quality of evidence as follows.
-
By one level: when the funnel plot suggests publication bias.
Appendix 3. Glossary
Anulus fibrosus: circular tissue that surrounds the soft inner core, the nucleus pulposus, of the intervertebral disc.
Fascia: tissue that encloses the muscle
Musculoligamentous: two tissues of the body (muscle and ligament) that connects to the bone and provide the movement.
Orthosis: external device applied to a region of the body with different functions.
Paravertebral: anatomical location along the vertebra.
Pedicle: part of the vertebra that connects the vertebral body to the vertebral arch and where the pedicle screw can be placed in spinal fusion.
Periosteum: fibrous membrane that covers all the bones.
Pseudarthrosis: non‐union of two bones after attempt to unite them (surgery) or after fracture.
Skin maceration: injury to the skin after prolonged exposure the moisture.
Thoracolumbosacral: region of the body which includes the thorax, the lumbar and the sacral region.
| Bias domain | Source of bias | Possible answers |
| Selection | (1) Was the method of randomisation adequate? | Yes/no/unsure |
| Selection | (2) Was the treatment allocation concealed? | Yes/no/unsure |
| Performance | (3) Was the patient blinded to the intervention? | Yes/no/unsure |
| Performance | (4) Was the care provider blinded to the intervention? | Yes/no/unsure |
| Detection | (5) Was the outcome assessor blinded to the intervention? | Yes/no/unsure |
| Attrition | (6) Was the drop‐out rate described and acceptable? | Yes/no/unsure |
| Attrition | (7) Were all randomized participants analysed in the group to which they were allocated? | Yes/no/unsure |
| Reporting | (8) Are reports of the study free of suggestion of selective outcome reporting? | Yes/no/unsure |
| Selection | (9) Were the groups similar at baseline regarding the most important prognostic indicators? | Yes/no/unsure |
| Performance | (10) Were co‐interventions avoided or similar? | Yes/no/unsure |
| Performance | (11) Was the compliance acceptable in all groups? | Yes/no/unsure |
| Detection | (12) Was the timing of the outcome assessment similar in all groups? | Yes/no/unsure |
| Other | (13) Are other sources of potential bias unlikely? | Yes/no/unsure |
| Table extracted from Furlan 2015 | ||
| 1 | A random (unpredictable) assignment sequence. Examples of adequate methods are coin toss (for studies with 2 |
| 2 | Assignment generated by an independent person not responsible for determining the eligibility of the patients. |
| 3 | Index and control groups are indistinguishable for the patients or if the success of blinding was tested among |
| 4 | Index and control groups are indistinguishable for the care providers or if the success of blinding was tested |
| 5 | Adequacy of blinding should be assessed for each primary outcome separately. This item should be scored ‐ for patient‐reported outcomes in which the patient is the outcome assessor (e.g., pain, disability): the blinding |
| 6 | The number of participants who were included in the study but did not complete the observation period or |
| 7 | All randomized patients are reported/analyzed in the group they were allocated to by randomization for the |
| 8 | All the results from all prespecified outcomes have been adequately reported in the published report of the |
| 9 | Groups have to be similar at baseline regarding demographic factors, duration and severity of complaints, |
| 10 | If there were no cointerventions or they were similar between the index and control groups. |
| 11 | The reviewer determines if the compliance with the interventions is acceptable, based on the reported |
| 12 | Timing of outcome assessment should be identical for all intervention groups and for all primary outcome |
| 13 | Other types of biases. For example: |
| Table extracted from Furlan 2015 | |
| Postoperative braces versus no postoperative braces for adults with degenerative lumbar diseases | |||
| Patient or population: adults with degenerative lumbar disease Settings: postoperative of degenerative lumbar disease Intervention: with postoperative braces Comparison: without postoperative braces | |||
| Outcomes | Outcome type (continuous/ dichotomous) | Outcome measure | Comments |
| Function | Continuous | Oswestry Disabilty Index (ODI), Roland‐Morris Questionnaire (RMQ) | medium‐term |
| Back pain | Continuous | Visual Analogue Scale (VAS) | medium‐term |
| Quality of life | Continuous | SF‐36 questionnaire | medium‐term |
| Use of analgesic medications | Dichotomous | Yes/no | short‐term |
| Postoperative complications | Dichotomous | Yes/no | medium‐term |
| Return to work | Dichotomous | Yes/no | long‐term |
| GRADE Working Group grades of evidence | |||
| Short‐term: less than 3 months after surgery Medium‐term: 3 to 6 months after surgery Long‐term: greater than 6 months after surgery | |||
