Study designs of evaluations included in the review
Randomised controlled trials were eligible for inclusion in this review. All of the included trials were double-blind and of a crossover design, and two included a washout period.
Specific interventions included in the review
Trials of oral melatonin, used in any dose for any length of time when compared with placebo, were eligible for inclusion. Sustained-release formulations were excluded. The doses of melatonin ranged from 0.5 to 7.5 mg, and melatonin was either given at specified times or one hour before bedtime.
Participants included in the review
Trials of children up to 18 years of age with any type of neurological disorder or neurodevelopmental disability and associated sleep disturbance were eligible for inclusion. The trials included children with at least moderate learning disability and fragmented sleep; Rett syndrome (most of whom were receiving anti-epileptic medication) and poor-quality sleep; and moderate developmental disability and significant sleep problems.
Outcomes assessed in the review
To be eligible, the trials had to report at least one of the following outcomes: total sleep time, time to sleep onset (sleep latency), number of awakenings, parental view of effect and adverse events. The included studies used sleep diaries completed by carers, or wrist actigraphy, to monitor sleep-wake activity.
How were decisions on the relevance of primary studies made?
The authors did not state how the studies were evaluated for inclusion in the review, or how many reviewers performed the selection.