OBJECTIVE: The study aimed to evaluate efficacy of tiotropium as add-on therapy on top of standard regimens for uncontrolled asthma, specifically in terms of FEV1, morning and evening PEF, reduction in exacerbations, rescue medication use, and quality of life improvement.
METHODS: A search was done for eligible trials after which validity screen and data extraction was performed. Results were presented as mean differences, standard errors, and 95% confidence intervals, and graphically as forest plots. Estimates were pooled using the random effects model with I2 and Chi2 tests used to assess heterogeneity. Adverse events were reported as dichotomous variables.
RESULTS: Four studies were included totaling 1617 participants. The tiotropium group had statistically significant improvement in FEV1 (95% Cl, 0.14 [0.09, 0.19], p<0.00001), morning (95% Cl, 20.03 [11.71, 28.35], p<0.00001) with trend towards benefit in reduction of rescue medications (95% Cl, 0.12 [-0.17,0.4],p=0.42) and quality of life improvements (95% Cl, 0.1 [-0.05,0.25], p=0.20). Homogeneity (I2= 0%, Chi2= 0.47-3.22) was found across studies.
CONCLUSION: Tiotropium is associated with significant improvement in pulmonary function among patients with uncontrolled asthma, with possible benefit in reduction of rescue medications and quality of life improvement.