Comparative Effectiveness of Two Tiotropium Formulations: A Retrospective Cohort Study

Area of Science:

• Pharmacology
• Respiratory Medicine
• Clinical Trials

Background:

• The generalizability of tiotropium Respimat® effectiveness from the Tiotropium Safety and Performance in Respimat® (TIOSPIR) trial to routine clinical practice remains under investigation.
• Real-world data is crucial to validate findings from controlled clinical trials.

Purpose of the Study:

• To compare the incidence of acute respiratory events between new users of tiotropium Respimat® and tiotropium HandiHaler® in a real-world setting.
• To assess the safety and effectiveness of different tiotropium formulations in a broader patient population.

Main Methods:

• A retrospective cohort study using Italian National Health Service drug prescription data.
• Inclusion criteria: patients aged ≥45 years with a first tiotropium prescription (Respimat® or HandiHaler®) between July 2011 and November 2013.
• Propensity score matching and Cox regression were used to analyze clinical outcomes, including hospitalization for respiratory events.

Main Results:

• 31,334 propensity score-matched patients were included in the analysis.
• No significant difference in the incidence of primary respiratory events was observed between tiotropium Respimat® and HandiHaler® users (adjusted hazard ratio: 0.95, 95% CI: 0.84-1.07).
• Subgroup analyses by baseline characteristics did not reveal any significant differences between the two formulations.

Conclusions:

• The effectiveness of tiotropium Respimat® in routine clinical practice is comparable to tiotropium HandiHaler®.
• These real-world findings corroborate the results of the TIOSPIR trial, extending their validity to a more heterogeneous patient population, including those with severe or unstable chronic obstructive pulmonary disease (COPD).