Sixty-seven studies were included in the review. All studies had quality scores greater than 65%.
Addiction (24 studies: 17 retrospective and seven prospective, n=2,507). The mean percentage of addiction was 3.3% overall (range 0 to 45%, mean exposure time was 26 months) and 0.2% in studies that preselected for no previous history of addiction versus 5% in the not-selected group.
Aberrant drug-related behaviours (total number of studies reported as 17, but eight retrospective and 10 prospective were included, n=2,466). The mean rate of aberrant drug-related behaviours was 11.5% (range 0 to 45%, mean exposure time 10.8 months) and 0.59% in studies that preselected for no previous history of aberrant drug-related behaviour versus 11.2% in the not-selected group.
Urine toxicology (five studies: two retrospective and three prospective, n=1,965). Illicit drugs were found in a mean of 14.5% of patients (range 4% to 57%). Exposure time reported by one study was 36 months.
Further results were reported.