Methods: The PubMed/MEDLINE, Cochrane Library, EMBASE,
Scopus, and CAMBASE databases were screened in August 2012
to identify randomized (RCTs) and nonrandomized controlled
clinical trials (CCTs) comparing leech therapy to control conditions.
Main outcome measures were pain, functional impairment,
and joint stiffness. For each outcome, standardized mean differences
(SMD) and 95% confidence intervals were calculated.