Table 3.
Evidence is assessed using four levels of quality as defined by the GRADE system
| GRADE score | Description | Agreed criteria within studies used for this comprehensive review |
|---|---|---|
| High quality | Further research is very unlikely to change our confidence in the estimate of effect | Randomization Control group Active placebo Homogenous sample of amputees PLP sole outcome or able to be clearly differentiated from other outcomes, for example, SP Sample size decided by power calculation or at least 50 (25 in cross-over studies) to enable comparative statistics to be performed |
| Moderate quality | Further research is likely to have an important impact on our confidence in the estimate of the effect and may change the estimate | Randomization Control group Inactive placebo Heterogeneous sample of amputees PLP sole outcome or able to be clearly differentiated from other outcomes, for example, SP Sample size not powered |
| Low quality | 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 | Prospective study/randomized study with no control group or very small sample size Heterogeneous sample of amputees PLP not sole outcome or unable to differentiate from other outcomes Small sample size or small number of sample with PLP |
| Very low quality | Any estimate of effect is very uncertain | Case study Very low number case series |
Source: Data from Guyatt et al.21
Abbreviations: PLP, phantom limb pain; SP, stump pain.