ORIGINAL ARTICLES
The Current Dilemma with Spirometric Inclusion Criteria for Asthma Drug Trials

https://doi.org/10.1016/S1081-1206(10)63006-2Get rights and content

Background

Spirometric inclusion criteria for asthma drug studies often require resting airflow obstruction and resting bronchoconstriction. By current standards, these criteria define suboptimal to poor asthma control.

Objective

To determine what proportion of asthmatic patients attending a tertiary University-based respiratory clinic meet typical drug study spriometric criteria of a baseline FEV1 of 50% to 80% predicted and ≥ 15% change in FEV1 improvement following 200 micrograms inhaled albuterol.

Methods

A retrospective review was performed on charts of white caucasian asthmatic patients attending three respiratory physician outpatient clinics at a University-based tertiary referral center. We reviewed charts of all patients with chronic asthma under current therapy. We excluded subjects with additional lung diseases that might affect lung function. Spirometric data were extracted from the most recent scheduled outpatient visit.

Results

We reviewed 590 charts of patients with mean age 35.3 ± 18.3 years (range 6 to 94), 43% male, and 50% atopic. There was objective evidence of variable airflow obstruction or airway hyperresonsiveness in 70.2%; the diagnosis of asthma was based on historical data alone in 29.8%. The majority of patients (87.5%) required inhaled corticosteroids with more than 50% using medium to high doses. Baseline FEV1 was >80% in 84.6% of subjects, 50% to 80% in 14.4%, and <50% in 1.0%. FEV1 improved by ≥15% 10 to 15 minutes after 200 micrograms inhaled albuterol in 13.6%. Only 9.0% of the 590 asthmatic patients fulfilled both criteria (FEV1 50% to 80% and Δ FEV1 ≥ 15%).

Conclusion

Less than 10% of asthmatic patients attending a tertiary referral respiratory clinic fulfilled typical spirometry inclusion criteria for asthma drug trials. We suggest this approach to enrollment in asthma drug studies be re-evaluated.

REFERENCES (14)

There are more references available in the full text version of this article.

Cited by (14)

  • The ethics of placebo-controlled trials: The case of asthma

    2005, Journal of Allergy and Clinical Immunology
    Citation Excerpt :

    Patients in such trials generally must meet precisely defined criteria regarding symptom scores, spirometry, and freedom from possibly confounding conditions, medications, and smoking. Consequently, most asthma investigators find that only a small percentage of patients with asthma are appropriate evaluable subjects for asthma trials.12 In trials designed to show equivalence, the incentive to conduct trials with such rigor would be reduced, making recruitment for the trial easier, but potentially compromising the validity of the trial.

  • The evaluable subject

    1998, Annals of Allergy, Asthma and Immunology
  • Environmental Causes of Asthma

    2018, Seminars in Respiratory and Critical Care Medicine
View all citing articles on Scopus
View full text