Background: Chinese herbal medicine (CHM) has been widely used in the treatment of Sjogren's syndrome. However, there remains no systematic review to assess the effectiveness and safety of CHM.

Objective: To assess the effectiveness and safety of CHM in the treatment of Sjogren's syndrome.

Search strategy: Literature was searched from PubMed, the Cochrane Library (Issue 3, 2010), the China National Knowledge Infrastructure Database, the Chongqing VIP Chinese Science and Technology Periodical Database, the Chinese Biomedical Literature Database (SinoMed), Wanfang Data and the Traditional Chinese Medical Periodical Literature Database. The time limitation ran from the commencement of each database to October 15, 2010.

Inclusion criteria: Randomized controlled trials (RCTs) testing CHM alone or in combination with Western medicine (WM) against WM or placebo used alone were included.

Data extraction and analysis: Two authors collected data independently. The assessment of methodological quality was based on the Cochrane handbook and the data were analyzed by using RevMan 5.0.17 software. Heterogeneity of the included studies was tested and use of statistical model was based on the heterogeneity. The efficacy measure was relative risk (RR) or mean difference with a 95% confidence interval (CI).

Results: A total of 52 RCTs involving 3 886 patients were included. The included trials were all of low quality. CHM was superior in improving clinical symptoms to WM, with statistical significance between the groups (RR:1.36; 95% CI: 1.24-1.49); CHM plus WM was better than WM used alone (RR: 1.38; 95% CI:1.30-1.46). CHM improved lacrimal gland function more effectively than WM, with statistical significance between the groups (RR:2.12; 95% CI:1.06-3.18); CHM plus WM was better than WM used alone (RR:1.90; 95% CI: 0.99-2.81). CHM was superior to WM in the improvement of erythrocyte sedimentation rate (RR:-9.63; 95% CI:-15.73--3.52), and CHM plus WM was also more effective than WM used alone (RR:-8.42; 95% CI:-14.71--2.13). However, there was no statistical difference between groups in other immune index (C-reactive protein, rheumatoid factor, IgG, IgA and IgM). The reported adverse effects of CHM were mainly gastrointestinal symptoms, such as diarrhea. The incidence of adverse effects of WM was higher than that of CHM.

Conclusion: CHM appears to improve the symptoms of Sjogren's syndrome. However, due to the low quality of included studies, further well-designed multicenter and large-scale RCTs are still needed to evaluate the beneficial effects of CHM.