Table 1 The quality review system for included trials.
| Â | Item | Score | Criteria |
|---|---|---|---|
| Â | Â | 2 | Randomization is described and adequate (random numbers, computer generated, etc.) |
| Â | Randomization | 1 | Randomization is described |
| Â | Â | 0 | No or inappropriate randomization |
| Â | Allocation | 2 | Allocation concealment is described and adequate (sequentially numbered opaque sealed envelopes, central randomization, etc.) |
| Â | concealment | 1 | Allocation concealment is described |
Adapted Jadad score | Â | 0 | No or inappropriate allocation concealment |
| Â | Intervention | 2 | Blinding is described and adequate |
| Â | blinding | 1 | Blinding is described |
| Â | Â | 0 | No or inappropriate blinding |
| Â | Withdrawal or | 1 | Withdrawals and dropouts are described |
| Â | dropouts | 0 | Withdrawals or dropouts are not described |
| Â | Intention-to-treat | 1 | ITT analysis is used |
| Â | (ITT) analysis | 0 | ITT analysis is not used |
| Â | Similar groups at baseline | 1 | Delirium-related factors (age, sex, pre-existing cognitive or sensory deficit, physical functional status, comorbid diseases, medications and alcohol consumption [12, 15, 16]) are similar between groups |
| Â | Â | 0 | Delirium-related factors are not screened or different |
Delirium specific score | Delirium assessor blinding | 1 | Delirium assessor is blinded to the interventions |
| Â | Â | Â | Delirium assessor is not blinded to the interventions |
|  |  | 2 | Frequency: ≥ 1/day since postoperative day (POD) 1 and duration: > 3 days since POD 1 [1, 14] |
|  | Delirium follow-up | 1 | Frequency: ≥ 1/day since POD 1 and duration: POD 1-3 |
| Â | Â | 0 | Frequency: < 1/day or duration < 3 days since POD 1 |