Table 1.

Characteristics of the studies and study patients

Author (year); Country	Drug (dose)		Duration of Therapy (days)	Study design / (blinding)	Reason for surgery	Patients N		Age Mean (SD) unless otherwise indicated		Male gender N (%)		Scale used to assess delirium	Mean (SD) duration of surgery (minutes)
	I	C				I	C	I	C	I	C		I	C
Artemiou (2015); Slovakia [30]	Melatonin (5 mg)	No treatment	5	Prospective observational (none)	Cardiac	250	250	64.3 (±10.1)	65.2 (±10.3)	179 (71.6)	171 (68.4)	CAM-ICU	NR	NR
de Jonghe (2014); The Netherlands [29]	Melatonin (3 mg)	Placebo	5	RCT (double)	Hip fracture	186	192	Mean (SD) 84.1 (±8)	Mean (SD) 83.4 (±7.5)	53 (28.5)	62 (32.3)	DSM-IV	NR	NR
Miyata (2017); Japan [31]	Ramelteon (8 mg)	Placebo	7	Retrospective chart review (none)	Pulmonary resection	24	58	79 (70–89)a	Median (Range) 76.5 (70–87)	21 (88)	43 (74)	ICDSC	293 (±108)	280 (±91.4)
Nickkholgh (2011); Germany [32]	Melatonin (50 mg/kg)	Placebo	1	RCT (double)	Liver resection	25	23	Mean (SD) 59 (±10)	Mean (SD) 56 (±11)	17 (68)	11 (48)	NR	202 (±80)	212 (±79)
Sultan (2010); Egypt [33]	Melatonin (5 mg)	No treatment	2	RCT (double)	Hip arthroplasty	53	49	Mean (SD) 70.4 (±7.1)	Mean (SD) 72.3 (±6.4)	24 (45.3)	22 (44.9)	AMT	126.8 (±44.9)	119.7 (±36.7)
Yamaguchi (2014); Japan [33]b	Ramelteon (8 mg)	Placebo	4	RCT (double)	Total knee arthroplasty	22	23	≥70	≥70	NR	NR	ICDSC	NR	NR

Abbreviations

I intervention group

C comparison group

Mg milligrams

Kg kilograms

NA Not applicable

RCT randomized controlled trial

SD standard deviation

NR not reported

CAM-ICU Confusion Assessment Method for the Intensive Care Unit

DSM-IV delirium observation screening scale

ICDSC intensive care delirium screening checklist score (delirium >/= 4)

AMT abbreviated mental test (delirium < 8)

Footnotes:

^aMedian (range).

^bAbstract only.