Table 3 Risk of bias of the randomised studies
From: General vs. neuraxial anaesthesia in hip fracture patients: a systematic review and meta-analysis
Author | Random sequence generation (selection bias) | Allocation concealment (selection bias) | Blinding of participants and personnel (performance bias) | Blinding of outcome assessment (detection bias) | Incomplete outcome data addressed (attrition bias) | Selective reporting (reporting bias) | Other bias |
|---|---|---|---|---|---|---|---|
Biboulet et al. 2012 [32] | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk |
Explanation | No information about the sequence generation process. | Method of concealment is not described. | Insufficient information about blinding of participants or personnel. | Insufficient information about blinding of outcome assessment. | No incomplete outcome data. | The paper included all expected outcome. | The authors described several limitations which could influence the outcome. |
Heidari et al. 2011 [33] | Low risk | Unclear Risk | Low risk | Unclear risk | Low risk | Low risk | Unclear risk |
Explanation | A random-number table was used. | Method of concealment is not described. | It was not possible to blind the patient or the anaesthetist. | Insufficient information about blinding of outcome assessment. | No incomplete outcome data. | The paper included all expected outcomes. | The author described several limitations, which could influence the outcomes. |
Parker et al. 2015 [31] | Unclear risk | Unclear risk | High risk | Low risk | Low risk | Low risk | Unknown risk |
Explanation | Randomisation was undertaken by the opening of sealed opaque numbered envelopes. The envelopes were prepared at the start of the study by a person independent to the study. | Randomisation was undertaken by the opening of sealed opaque numbered envelopes. The envelopes were prepared at the start of the study by a person independent to the study. | The exact technique and doses of the anaesthetic used was the choice of the anaesthetist. On the verge of surgery the patient knows if he gets a general or spinal anaesthesia. | There was no blinding of investigator, participants or outcome assessors without having influence on outcomes like 30-day mortality. | Attrition <1%. | No important outcomes missing. | Small numbers of patients being included. |