OBJECTIVETo evaluate the efficacy and safety of tiotropium in treatment of severe persistent asthma.

METHODSReports of randomized controlled trials (RCTs) describing tiotropium for treatment of severe persistent asthma published from January 1946 to February 2015 were searched in Cochrane Library, ClinicalTrials.gov, PubMed, Ovid Medline, CNKI, and CSJD. The data of the included RCTs were extracted and the data quality was evaluated. Meta-analyses were performed with Revman 5.3 software.

RESULTSFive RCTs including 1433 patients were analyzed. Meta-analysis of the data showed that compared with the placebo group, tiotropium treatment significantly improved the patients' peak forced expiratory volume in one second (FEV1) [weighted mean difference (WMD): 0.13 L, 95% confidence interval (CI): 0.10-0.16 L, P<0.00001], trough FEV1 (WMD: 0.09 L, 95%CI: 0.06-0.12 L, P<0.00001), peak forced vital capacity (FVC) (WMD: 0.10 L, 95%CI: 0.06-0.14 L, P<0.00001), trough FVC (WMD: 0.12 L, 95%CI: 0.08-0.17 L, P<0.00001), morning peak expiratory flow (PEF) (WMD: 9.21 L/min, 95%CI: 4.2-14.23 L/min, P=0.0003), evening PEF (WMD: 22.06 L/min, 95%CI 13.05-31.08 L/min, P<0.00001). The scores of asthma control questionnaire (ACQ) (WMD: 0.01, 95% CI: -0.07-0.09, P=0.86) or asthma quality of life questionnaire (AQLQ)(WMD: 0.06, 95% CI:-0.18-0.06, P=0.33) were not affected by tiotropium. No significant difference with adverse events between tiotropium group and placebo group were reported in these included studies (P>0.05).

CONCLUSIONSTiotropium for severe persistent asthma treatment can improve FEV1, FVC, and PEF but may not improve the quality of life of the patients. Tiotropium is well tolerated and can be an add-on therapy for severe persistent asthma.