Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Sleep quality and duration
RCT	84 inpatients with insomnia, recruited from geriatric centres	Sleep-latency score (scale: 1 = <15 minutes, 2 = 15–30 minutes, 3 = 30–60 minutes, and 4 = >60 minutes) 28 days 2.0 with zolpidem 10 mg 2.1 with zolpidem 20 mg	Reported as not significant		Not significant
RCT	84 inpatients with insomnia recruited from geriatric centres	Number of awakenings score (scale: 0 = no awakenings, 1 = once, 2 = 2–3 times, 3 = 4 or more) 28 days 1.6 with zolpidem 10 mg 1.7 with zolpidem 20 mg	Reported as not significant		Not significant
RCT	60 inpatients in a neurology department with moderate to severe insomnia	Sleep quality and duration 60 days with zolpidem 10 mg with zolpidem 20 mg Absolute results not reported	No significant difference reported between treatments for significant improvements in sleep latency, total sleep time, number of awakenings, and overall sleep quality compared with baseline		Not significant