Comorbidities of patients in tiotropium clinical trials: comparison with observational studies of patients with chronic obstructive pulmonary disease

Marc Miravitlles, David Price, Klaus F Rabe, Hendrik Schmidt, Norbert Metzdorf, Bartolome Celli

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)
7 Downloads (Pure)


BACKGROUND: There is an ongoing debate on whether patients with chronic obstructive pulmonary disease (COPD) seen in real-life clinical settings are represented in randomized controlled trials (RCTs) of COPD. It is thought that the stringent inclusion and exclusion criteria of RCTs may prevent the participation of patients with specific characteristics or risk factors.

METHODS: We surveyed a database of patients recruited into 35 placebo-controlled tiotropium RCTs and also conducted a systematic literature review of large-scale observational studies conducted in patients with a documented diagnosis of COPD between 1990 and 2013. Patient demographics and comorbidities with a high prevalence in patients with COPD were compared between the two patient populations at baseline. Using the Medical Dictionary for Regulatory Activities (MedDRA; v 14.0), patient comorbidities in the pooled tiotropium RCTs were classified according to system organ class, pharmacovigilance (PV) endpoints, and Standardised MedDRA Queries to enable comparison with the observational studies.

RESULTS: We identified 24,555 patients in the pooled tiotropium RCTs and 61,361 patients among the 13 observational studies that met our search criteria. The Global initiative for chronic Obstructive Lung Disease (GOLD) staging of patients in the RCTs differed from that in observational studies: the proportion of patients with GOLD stages I+II disease ranged from 40.0% to 51.5% in the RCTs but 24.5% to 44.1% in the observational studies; for GOLD stage III or IV disease these ranges were 7.2%-45.8% (RCTs) and 13.7-42.1% (observational studies). The comorbidities with the highest prevalence reported in the RCTs and observational studies were: hypertension (39.4%-40.0% vs 40.1%-60.6%), other ischemic heart disease (12.3%-14.2% vs 12.5%-41.0%), diabetes (10.3%-10.9% vs 4.0%-38.9%), depression (8.5%-9.5% vs 17.0%-20.6%), and cardiac arrhythmia (7.8%-11.4% vs 11.3%-15.8%).

CONCLUSION: The clinical profile of COPD patients treated in the tiotropium trial program appears to be largely in the range of clinical characteristics, including cardiovascular comorbidities, reported for "real-life patients." The tiotropium RCTs tended to include patients with more severe disease than the observational studies.

Original languageEnglish
Pages (from-to)549-564
Number of pages16
JournalInternational journal of chronic obstructive pulmonary disease
Publication statusPublished - 16 Mar 2015

Bibliographical note

The authors are fully responsible for all content and editorial decisions made, were involved at all stages of manuscript development, and have approved the final version for publication. Editorial assistance, supported financially by Boehringer Ingelheim and Pfizer, was provided by Godfrey Lisk of PAREXEL International during the preparation of this manuscript.

This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution - Non Commercial (unported, v3.0) License. The full terms of the License are available at Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. Permissions beyond the scope of the License are administered by Dove Medical Press Limited.


  • patient population
  • baseline characteristics
  • epidemiology
  • real-life patients
  • GOLD staging


Dive into the research topics of 'Comorbidities of patients in tiotropium clinical trials: comparison with observational studies of patients with chronic obstructive pulmonary disease'. Together they form a unique fingerprint.

Cite this