Data Extraction
Data were extracted from all reports of studies that were
included in the review using a standardized Data Extraction
Form. The type of information extracted from reports
included details of study design and inclusion/exclusion criteria;
details of the population such as gender, age, ethnicity, and type
of sleep disorder; the number of individuals that were eligible
for, and enrolled in, the study; the number of comparison
groups and participants allocated to each group; the number of
participants who withdrew from the study; details of the
intervention such as the formulation, dosage, timing, frequency
and duration of melatonin administration as well as the type
and frequency of usage of concurrent medication; and results
obtained for predetermined, question-specific outcomes.
Additional information that was extracted from reports
included the source of funding for the study and whether an
intention-to-treat analysis was planned or performed. A trained
reviewer extracted relevant data from a given report and a
second reviewer verified the data that were extracted for that
article for accuracy and completeness. Disagreements between
reviewers were resolved by discussion and consensus.