| Methods |
|
| Participants |
|
| Interventions |
|
| Outcomes |
|
| Notes |
See Table 8
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
"One of three numbered but unlabelled tapes was randomly assigned to the patient by computer‐generated random number table. The randomisation was stratified according to estimated length of stay (less than 2 days and more than this)." |
| Allocation concealment (selection bias) |
Unclear risk |
Unclear if the person recruiting patients was aware of the randomisation schedule. |
| Blinding (performance bias and detection bias)
Subjective outcomes |
Unclear risk |
Study did not address subjective outcomes |
| Blinding (performance bias and detection bias)
Objective outcomes |
Low risk |
Fentanyl requirements: "throughout the study, the anaesthetist remained unaware of the nature of the tape" |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
"Eighty‐three of these gave their informed consent but seven later revoked this in the induction room" Description of reasons and group allocation not given. Data presented on all remaining included participants. |
| Selective reporting (reporting bias) |
Unclear risk |
Unknown if selective outcome reporting. |
| Protection from contamination? |
Low risk |
Interventions administered on an individual basis. |
