Randomised clinical trials on acupuncture in the Korean literature: bibliometric analysis and methodological quality

Objective Acupuncture systematic reviewers have increasingly searched Chinese databases and journals to identify eligible randomised clinical trials (RCTs). However, reviewers have infrequently searched for eligible RCTs in Korean databases and journals. This study aimed to identify difficult to locate acupuncture RCTs in Korean databases and journals and to assess the characteristics and quality of the identified RCTs. Methods Eleven electronic databases and seven journals were searched up to December 2012. All RCTs using needle acupuncture were considered for inclusion. Key study characteristics were extracted and risk of bias was assessed using the Cochrane Collaboration tool. Results One hundred and forty-three publications met our inclusion criteria. Acupuncture RCTs in the Korean literature emerged in the mid-1990s and increased in the mid-2000s. Diverse methods of acupuncture were used, including some methods unique to Korea (eg, Saam acupuncture). The largest proportion of trials evaluated acupuncture for musculoskeletal conditions (27.3%). The mean sample size was 44.3±25.3 per trial. Random sequence generation methods were reported in 44.8% of the RCTs, whereas only 11.9% reported methods of allocation concealment. A low proportion of trials reported participant blinding (32.9%) and outcome assessment blinding (18.9%). Conclusions Korean acupuncture trials, many of which evaluate acupuncture styles unique to Korea, are typically omitted from systematic reviews of acupuncture, resulting in the potential for language bias. The development of this database of difficult to locate Korean trials, which includes English language translations of abstracts, will enable these trials of varying quality to be assessed for inclusion in future acupuncture systematic reviews.