1. The clinical efficacy of tiotropium as add-on treatment to ICS with a LABA have been demonstrated in clinical trials in adult patients with symptomatic asthma.
2. Certain patients of daily care, like patients with smoking asthma, late onset asthma or asthma with chronic airway obstruction are often excluded from clinical trials.
3. Studies have shown the cognitive function of patients with COPD is impaired. When mixed types of inhaler devices are prescribed, the multiple steps of different devices may ensure complexity and confusion for patients, which may compromise the efficacy of add-on therapy. The inhaler error of add-on tiotropium treatment in real-world asthma treatment is unknown.
4. The improvement of step errors after varieties of teaching intervention is around 30\~50%. Strategy of recheck inhaler technique recommended by the treatment guideline may optimized inhaler use. (https://ginasthma.org/gina-reports/).
5. Factors like responseness of short-acting bronchodilators and cholinergic tone have been reported as predictors of a positive clinical response of add-on tiotropium. However, more specific physiological or inflammatory factors. e.g. exhaled nitric oxide test (FeNo), and para symptomatic function and cardiac-pulmonary interaction have not been evaluated prospectively.
6. This pragmatic, two-arm, randomized controlled trial study aim to survey the inhaler errors of add-on tiotropium therapy with ICS+LABA in real-world practice of asthma patients and the efficacy of recheck stratage of inhaler skills. Patient characteristics and inflammatory features will be evaluated prospectively for association of asthma control by add-on tiotropium.
