Heterogeneity in search strategies among Cochrane acupuncture reviews: Is there room for improvement?

Objective: Given the international focus and rigorous literature searches employed in Cochrane systematic reviews, this study was undertaken to evaluate strategies employed in Cochrane reviews and protocols assessing acupuncture as a primary or secondary intervention.

Methods: The Cochrane Collaboration of systematic reviews was searched in February 2009 for all reviews and protocols including information on acupuncture. Information was abstracted from all retrieved articles on review status, type and number of English and Chinese language databases searched, participation of at least one Chinese speaking author and language restriction. Frequencies were calculated and bivariate analyses were performed stratifying on interventions of interest to assess differences in search strategy techniques, language restrictions and results.

Results: The search retrieved 68 titles, including 48 completed reviews, 17 protocols and three previously withdrawn titles. Acupuncture was the primary intervention of interest in 44/65 (67.7%) of the retrieved reviews and protocols. While all articles searched at least one English language database, only 26/65 (40.0%) articles searched Chinese language databases. Significantly more articles where acupuncture was the primary intervention of interest searched Chinese language databases (53% vs 9%, p<0.01). Inconclusive findings as to the effectiveness of acupuncture were found in 28/48 (58.3%) of all completed reviews; this type of finding was more common in reviews which did not search any Chinese language databases.

Conclusions: It is important for reviews assessing the effectiveness of acupuncture to search Chinese language databases. The Cochrane Collaboration should develop specific criteria for Chinese language search strategies to ensure the continued publication of high-quality reviews.