| Study |
Bias |
| Randomisation process |
Deviations from intended interventions |
Missing outcome data |
Measurement of the outcome |
Selection of the reported results |
Overall |
| Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
Authors' judgement |
Support for judgement |
| de Vos 2014 |
Low risk of bias |
Randomisation block stratified by centre. Allocation concealed. No apparent baseline imbalance. |
Some concerns |
Open‐label study without blinding of participants and personnel and no information provided to assess deviations in the medical management across groups. |
Low risk of bias |
Low levels of missing data and balanced between groups (7.5% SCS group, 10% CMM group). Authors shared complete dataset which indicates no meaningful bias. |
High risk of bias |
Open label study of a complex, invasive intervention with a subjective self‐reported outcome (Pain VAS). |
Low risk of bias |
While no protocol or full SAP is available sharing of the full dataset by the study authors indicates no evidence of selectivity. |
High risk of bias |
High risk of bias based on bias in the measurement of the outcome. |
| Kemler 2000 |
Low risk of bias |
Computer generated randomisation. Allocation concealed. Minor imbalance of gender (61%F in SCS group and 83%F in PT group) but compatible with chance. |
Some concerns |
Open label study without blinding of participants and personnel and no information provided to assess deviations in PT management across groups. |
Low risk of bias |
Only 1 participant in PT only group lost to follow up at this time‐point |
High risk of bias |
Open‐label study of a complex, invasive intervention with a subjective self‐reported outcome (Pain VAS). |
Some concerns |
No trial registry record, SAP or protocol available. |
High risk of bias |
High risk of bias based on bias in the measurement of the outcome. |
| SENZA‐PDN |
Low risk of bias |
Computer generated randomisation. Allocation concealed. No apparent baseline imbalance. |
Some concerns |
Open‐label study without blinding of participants and personnel and no information provided to assess deviations in the medical management across groups. An ITT approach is reported, though there are a number of post‐randomisation exclusions. |
High risk of bias |
Post randomisation exclusions took place prior to pre‐implantation trial period and were omitted from the analysis. In total at 1 month there are 16% of randomised participants excluded from the SCS group and 9% from the CMM group. It is possible that exclusions may be related to the value of the outcome. |
High risk of bias |
Open label study of a complex, invasive intervention with a subjective self‐reported outcome (Pain VAS). |
Some concerns |
While an SAP is available it is unclear whether it was finalised and unchanged ahead of the end of data collection. While authors shared data on request, they remained post‐randomisation exclusions and the N of participants analysed do not clearly match those in the CONSORT flow chart. |
High risk of bias |
High risk of bias on mutliple domains |
