Table 1

 Characteristics of untagged and tagged reports classified as not describing randomised controlled trials (RCTs)*

CharacteristicsNo (%) of untagged records (n=19)No (%) of tagged records (n=16)
Quasirandomised trial1 (5)2 (13)
Meta-analysis or review3 (16)2 (13)
RCT briefly mentioned8 (42)0 (0)
Unrelated to RCT or CCT7 (37)12 (75)

CCT=controlled clinical trial.

*Untagged records (19/591) were originally identified by Cochrane searchers as RCTs, but are classified here as non-RCTs. Tagged records (16/594) were indexed by the US National Library of Medicine as RCTs but are classified here as non-RCTs.