Chronic obstructive pulmonary disease (COPD) is one of the commonest respiratory diseases.
During the early stage of COPD, patients only have mild respiratory symptoms or signs which
may lead to under-diagnosis of the disease. Patients may show poor response to treatment at
later stages of the disease, associated with higher mortality and incidence of
re-hospitalization and disability causing burden for both the families and the society.
So far, there is no large-scale clinical trial on long-term intervention with tiotropium
bromide (Spiriva) in patients with early stages of COPD (i.e. GOLD Stage I-II COPD or
asymptomatic COPD). It would be of great significance for COPD prevention and treatment if
the investigators could prove that tiotropium decreases the lung function decline and
reverses disease progression in patients with early-stage COPD.
The investigators objective is to evaluate the efficacy of long-term intervention with
tiotropium in early stage (FEV1 ≥50% predicted) COPD (difference of trough FEV1, number of
exacerbations, time to first exacerbation, quality of life, etc) and relevant