| 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 |
| Subgroup 1.2.1 Peripheral nerve block based on landmarks |
| Godoy Monzon 2010 |
Low risk of bias |
Randomized using numbers generated by a computer. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
High risk of bias |
88% of included participants analyzed: 92 for the intervention group and 62 for the comparator group. We were uncertain if missingness was related to the outcome or not. Therefore, we deemed it prudent to judge this trial at high risk of bias for this domain for this outcome. |
Low risk of bias |
Delirium. To be qualified as delirious, a patient has to show clear symptoms of disorientation. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as delirious or not. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
High risk of bias |
Judged as at high risk of bias for this outcome due to high number of missing data and inability to determine whether or not missingness was related to this outcome |
| Mouzopoulos 2009 |
Low risk of bias |
Computer‐generated randomization code. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
95% of included participants were analyzed. |
Low risk of bias |
Diagnosis of the syndrome was defined using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM‐IV) and Confusion Assessment Method (CAM) criteria [1, 21]. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Nie 2015 |
Low risk of bias |
Randomly assigned according to a computer‐generated random number table. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
98% of included participants were analyzed. |
Low risk of bias |
The Confusion Assessment Method was used to diagnose delirium pre‐ and postsurgery. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| White 1980 |
Low risk of bias |
Patients were randomly allocated. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
Participants with failed block were excluded: 4/20 no other exclusion. So, 90 % of included participants analyzed. |
Low risk of bias |
Confusion. To be qualified as confused, a patient has to show clear symptoms of disorientation. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as confused or not. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Subgroup 1.2.2 Peripheral nerve block based on nerve stimulator |
| Cuvillon 2007 |
Low risk of bias |
Randomized using sealed numbered envelopes. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
100% of included participants were analyzed. |
Low risk of bias |
Results are given for sedation and/or confusion. To be qualified as confused, a patient has to show clear symptoms of disorientation. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as confused or not. Participants in comparator groups received less morphine than the block group, we therefore have no reason to believe that the highest number of participants with sedation and or confusion in the comparator group were assessed as positive for this outcome because they were excessively sedated from morphine. Also, results of this trial are consistent with results of the other trials included in the analysis. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Graham 2008 |
Low risk of bias |
Randomized by numbered, sequential, sealed opaque envelopes. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
85% of included participants were analyzed. |
Low risk of bias |
Confusion. To be qualified as confused, a patient has to show clear symptoms of confusion. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as confused or not. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Kullenberg 2004 |
Low risk of bias |
Randomized using the envelope method. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
100% of included participants were analyzed. |
Low risk of bias |
An experienced nurse evaluated patients' mental status with the Short Portable Mental Status Questionnaire, Pfeiffer‐test, graded according to a 4‐degree scale. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Subgroup 1.2.3 Peripheral nerve blocks inserted on ultrasound guidance |
| Brownbridge 2018 |
Low risk of bias |
Patients were randomized. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
100% of included participants were analyzed. |
Low risk of bias |
CAM‐ICU scoring system will be used daily to measure delirium. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Liebmann 2012 |
Low risk of bias |
Randomization occurred using an Internet‐based program. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
95% of included participants were analyzed. |
Low risk of bias |
Confusion. To be qualified as confused, a patient has to show clear symptoms of disorientation. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as confused or not. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Morrison 2008 |
Low risk of bias |
Randomized using a computer‐generated, stratified, blocked randomization list, with stratification according to site and allocation concealed in sealed envelopes. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
95% of included participants were analyzed. |
Low risk of bias |
Confusion Assessment Method supplemented by chart review evaluated by an assessor blinded to the treatment group. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Uysal 2018 |
Low risk of bias |
A randomized controlled trial. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
83% of included participants were analyzed. |
Low risk of bias |
The delirium status of patients was assessed using “Delirium Rating Scale‐R‐98 (DRS‐R‐98)” in the postoperative period for three days. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Yamamoto 2016 |
Low risk of bias |
Randomisation was performed with a random number list generated by a computer software. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
100% of included participants were analyzed. |
Low risk of bias |
Delirium occurring within 24 h after surgery was diagnosed by the confusion assessment method. The method chosen to evaluate the outcome makes it unlikely to be influenced by possible knowledge of assignment. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
| Yang 2016 |
Low risk of bias |
Randomized. No baseline differences between intervention groups identified. |
Low risk of bias |
No deviations from intended interventions identified. |
Low risk of bias |
100% of included participants were analyzed. |
Low risk of bias |
Delirium. To be qualified as delirious, a patient has to show clear symptoms of disorientation. It seems to us that knowledge of the intervention group was not likely to influence the fact that a patient was diagnosed as delirious or not. |
Low risk of bias |
No deviation to the planned statistical analysis identified. Only one result provided. |
Low risk of bias |
No risk of bias identified. |
