Meta-analysis of clinical trials on traditional Chinese herbal medicine for treatment of persistent allergic rhinitis

Background: Chinese herbal medicine (CHM) has been used for the prevention and treatment of persistent allergic rhinitis (PAR), but results are still equivocal. This study was to assess the clinical effectiveness of CHM in patients with PAR. Materials and methods: Databases searched included articles published in the Cochrane library, MEDLINE, EMBASE, China National Knowledge Infrastructure, and Wanfang database from 1999 to 2011. The studies included were randomized controlled trials (RCTs) comparing CHM to placebo if they included patients with PAR. The main outcomes were the changes in the standardized mean difference (SMD) of nasal symptom scores and total serum IgE level. Methodological quality was assessed by the modified Jadad's scale. Results: Seven RCTs with 533 patients were identified and analyzed. In the meta-analysis, CHM reduced the total nasal symptom scores compared to placebo (SMD, -1.82; 95% confidence interval [CI], -3.03 to -0.62; P = 0.003). The effect estimate was in favor of the CHM intervention (SMD, -1.09; 95% CI, -2.74 to 0.55) in reducing the total serum IgE level, although this was not significant (P = 0.19). Conclusions: CHM interventions appear to have beneficial effects in patients with PAR. However, the published efficacy studies are too small to draw firm conclusion.