Rasmussen 1989a.
Methods |
|
|
Participants | 1. 200 admitted for elective total unilateral hip replacement were enrolled Number of patients randomized per arm: unclear 2. 17 patients (8.5%) were excluded from analysis, in the pre and postoperative period. It was impossible to perform the spinal procedure with the prescribed 25 G needle in 4 patients; 7 had an incomplete block, of whom 5 had a supplementary general anaesthetic and 2 another spinal injection; 4 had major cardiovascular complications, 1 had a classical migraine first noticed postoperatively and another needed a further spinal anaesthetic on the second postoperative day because the artificial hip dislocated. 183 patients were analysed:
3. Main characteristics of patients:
|
|
Interventions |
|
|
Outcomes | Outcomes were not classified as primary or secondary
|
|
Notes |
|
|
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Unclear risk | Insufficient information to score this item as low or high risk of bias. Quote: "The patients were randomly allocated in a double blind manner (..)" (page 184) |
Allocation concealment (selection bias) | Unclear risk | Insufficient information to score this item as low or high risk of bias |
Blinding of participants (performance bias) | Low risk | Quote: "The authors as well as the patients were blinded with respect to needle size" (page 571) "Spinal anaesthesia was performed by the department anaesthetists, but did not include the authors." (page 571) |
Blinding of outcome assessment (detection bias) All outcomes | Low risk | Quote: "The authors as well as the patients were blinded with respect to needle size" (page 571) "The patients in study 1 were interviewed by one of the authors on the fourth day after surgery (...)" (page 571) |
Incomplete outcome data (attrition bias) All outcomes | Low risk | 8.5% of patients were lost to follow‐up |
Selective reporting (reporting bias) | High risk | Adverse events, additional to PDPH, were not reported |
Other bias | Low risk | No other biases were identified |