Comparison 4. Prophylactic melatonin versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Incident delirium	3	529	Risk Ratio (M‐H, Random, 95% CI)	0.41 [0.09, 1.89]
2 Duration of delirium	1	104	Mean Difference (IV, Random, 95% CI)	0.0 [‐0.57, 0.57]
3 Severity of delirium (binary severe vs. not severe)	1	104	Risk Ratio (M‐H, Random, 95% CI)	0.86 [0.58, 1.27]
4 Severity of delirium (DRS‐R‐98)	1	6	Mean Difference (IV, Random, 95% CI)	‐4.10 [‐19.47, 11.27]
5 Length of admission	2	500	Mean Difference (IV, Random, 95% CI)	0.09 [‐1.20, 1.39]
6 Cognitive impairment	1	378	Risk Ratio (M‐H, Random, 95% CI)	0.86 [0.70, 1.04]
7 Activities of daily living	1	369	Mean Difference (IV, Random, 95% CI)	0.0 [‐1.20, 1.20]
8 Use of psychotropic medication (binary)	1	122	Risk Ratio (M‐H, Random, 95% CI)	0.87 [0.64, 1.18]
9 Antipsychotic medication use (cumulative)	1	378	Mean Difference (IV, Random, 95% CI)	‐1.0 [‐1.79, ‐0.21]
10 Benzodiazepine use (cumulative)	1	378	Mean Difference (IV, Random, 95% CI)	‐11.60 [‐24.34, 1.14]
11 Withdrawal from study	2	165	Risk Ratio (M‐H, Random, 95% CI)	1.0 [0.15, 6.87]
12 In‐hospital mortality	3	543	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.37, 1.88]
13 Mortality by 3 months	1	378	Risk Ratio (M‐H, Random, 95% CI)	0.98 [0.67, 1.45]
14 Adverse events	1	43	Risk Ratio (M‐H, Random, 95% CI)	0.0 [0.0, 0.0]