Studies that described the relationship between physician work hours and patient safety and reported outcomes directly related to patient safety (such as rates of complications, medical errors and misdiagnosis) were eligible for inclusion.
The number of hours worked by physicians varied between included studies. Outcomes reported were: complications, malpractice, post-partum haemorrhage, neonatal resuscitations, accidents/injuries and misdiagnosis.
The author did not state how many reviewers selected studies for inclusion.