Treatment needs in mild-to-moderate chronic obstructive pulmonary disease: evidence from longitudinal studies

Mild-to-moderate chronic obstructive pulmonary disease (COPD) requires treatment to delay disease progression, but this need is often overlooked. We aim to identify common clinical indicators that can reflect the risk of disease progression, rapidly informing individualized and early-stage intervention strategies.

Patients in the placebo groups of two clinical trials (NCT01455129 and ChiCTR-IIR-17012604) were included as the discovery and validation cohorts. Patients with severe conditions [i.e., forced expiratory volume in one second (FEV₁) ≤60%, COPD assessment test (CAT) ≥10, or frequent acute exacerbations of COPD (AECOPD) history] at baseline or experienced annualized clinically important deterioration (CID, 60 mL in FEV₁, 2 points in CAT, or frequent AECOPD) during follow-up were considered to have treatment needs. Sankey diagrams were employed to show the relationship between treatment needs at baseline and follow-up. Logistic regression was used to examine the association between baseline indicators and the risk of annualized CID. The incident rate ratio (IRR) was used to assess the efficiency of tiotropium in controlling annualized CID risk.

In the discovery cohort, over 50% of patients without severe conditions at baseline experienced annualized CID during follow-up. Continued smoking, smoking pack-years ≥30, and positive bronchodilator response (BDR) were associated with increased risk of annualized CID in both the discovery [odds ratio (OR) =1.96, 1.76, and 2.47, respectively] and validation cohorts (OR =2.82, 3.23, and 3.49, respectively). Tiotropium could reduce the risk of annualized CID [IRR =0.61, 95% confidence interval (CI): 0.51-0.72].

In patients with mild-to-moderate COPD, half may experience disease progression and are characterized by continued smoking, a smoking history of ≥30 pack-years, and a positive BDR. These risks of disease progression could be partly decreased with tiotropium inhalation.