Appropriate Inhaler Use of Tiotropium As Add-on Therapy in Symptomatic Asthma

One month after recruitment and every 3 months. 1. Check the inhaler step errors of patients by research assistant; 2.Demonstrate the right way by research assistant; 3. give the inhaler check list with marks of the wrong step(s) patients made to patients and 4. confirm the patients do the right way of the previous wrong step(s).

One month after recruitment and every 3 months.1. Check the inhaler step errors of patients by research assistant; 2. Verbal instruction with a physical demonstration will be given by educational nurse in usual care.