Consistently very poorly controlled asthma, as defined by the impairment domain of the Expert Panel Report 3 guidelines, increases risk for future severe asthma exacerbations in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study

Received 23 December 2008; received in revised form 6 July 2009; accepted 24 July 2009. published online 08 October 2009.

Background

Identification of patients at risk for asthma exacerbations can assist physicians in addressing disease management and improve asthma-related health outcomes.

Objective

We sought to evaluate whether level of impairment, as defined by the 2007 asthma guidelines, predicts risk for future asthma exacerbations.

Methods

The study included children aged 6 to 11 years (n = 82) and adolescent/adult patients aged 12 years and older (n = 725) from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study with data representing all components of the impairment domain of the asthma guidelines at baseline, month 12, and month 24. Patients were categorized into 2 cohorts: (1) consistently very poorly controlled (VPC) asthma from baseline through 2 years of follow-up and (2) improved from VPC asthma at baseline (including patients who improved to not well-controlled or well-controlled asthma), with improvement maintained through 2 years of follow-up. Odds ratios (ORs) and 95% CIs for risk of asthma exacerbations at month 30 were generated by using multivariable logistic regression by age group.

Results

After adjustment, children with consistently VPC asthma over the 2-year period demonstrated a 6-fold increased risk of hospitalization, emergency department visit, or corticosteroid burst (OR, 6.4; 95% CI, 1.2-34.5) compared with the improved group. Adolescent/adult patients with consistently VPC asthma were more likely to have a corticosteroid burst (OR, 2.8; 95% CI, 1.7-4.8) or have a hospitalization, emergency department visit, or corticosteroid burst (OR, 3.2; 95% CI, 1.9-5.3).

Conclusions

Consistently VPC asthma, as defined by the impairment domain of the 2007 asthma guidelines, is strongly predictive of future asthma exacerbations.

Key words: Asthma, asthma guidelines, impairment domain, risk, exacerbations, health care use, asthma control, The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study

Abbreviations used: ATAQ, Asthma Therapy Assessment Questionnaire, ED, Emergency department, NHLBI, National Heart, Lung, and Blood Institute, NWC, Not well controlled, OR, Odds ratio, TENOR, The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens, VPC, Very poorly controlled, WC, Well controlled

a Genentech, Inc, South San Francisco, Calif

b Department of Allergy, Kaiser Permanente Southern California, San Diego, Calif

c Department of Pediatrics, National Jewish Health, Denver, Colo

d ICON Clinical Research, San Francisco, Calif

e Capital Allergy and Respiratory Disease Center, Sacramento, Calif

f University of Manitoba, Winnipeg, Manitoba, Canada

g Channing Laboratory, Harvard Medical School, Boston, Mass

h University of Pittsburgh Asthma Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pa

i University of Virginia Health Systems, Charlottesville, Va

j Wake Forest University Health Sciences, Winston-Salem, NC

Reprint requests: Tmirah Haselkorn, PhD, Genentech, Inc, 1 DNA Way, MS 58B, South San Francisco, CA 94080.

Supported by Genentech, Inc, and Novartis Pharmaceuticals Corporation.

Disclosure of potential conflict of interest: J. E. Fish is an employee of Genentech. R. S. Zeiger is a consultant for Aerocrine, AstraZeneca, Genentech, GlaxoSmithKline, Merck, Novartis, and Schering and has received research support from Aerocrine, Sanofi-Aventis, Genentech, Merck & Co, and GlaxoSmithKline. S. J. Szefler is a consultant for GlaxoSmithKline, Genentech, and Merck and has received research support from the National Institutes of Health (NIH)/National Heart, Lung, and Blood Institute (NHLBI) Childhood Asthma Management Program (CAMP), NHLBI Childhood Asthma Research and Education, the NIH/NHLBI Asthma Clinical Research Network, the NIH/National Institute of Allergy and Infectious Diseases Inner City Asthma Consortium, Roos Pharmaceuticals, and GlaxoSmithKline. D. P. Miller is employed by ICON Clinical Research, which received research funding from Genentech. B. E. Chipps has received research support from Genentech, Alcon, and AstraZeneca; has provided expert witness testimony for AstraZeneca regarding Symbicort research; and is a consultant on the speakers' bureau for Sepracor, GlaxoSmithKline, AstraZeneca, Alcon, Genentech, Novartis, Schering-Plough, Aventis, MADA. F. E. R. Simons has received research support from the Canadian Institutes of Health Research. S. T. Weiss is a consultant for Genentech. S. E. Wenzel has received research support from GlaxoSmithKline and is an advisory board member for the Global Initiative for Asthma. L. Borish is a consultant for Genentech, is on the speakers' bureau for Merck, and has received research support from GlaxoSmithKline. E. R. Bleecker is a consultant for AstraZeneca, Boehringer-Ingelheim, Centocor, Genentech, GlaxoSmithKline, Novartis, Pfizer, Wyeth, and Merck and has received research support through Wake Forest University Health Sciences, Aerovance, Amgen, AstraZeneca, Boehringer-Ingelheim, Centocor, Ception, Genentech, GlaxoSmithKline, Novartis, Novartis, Pfizer, and Wyeth. T. Haselkorn has been a paid consultant to Genentech since December 2002.

∗ For a complete list of TENOR Study Group members, please contact Genentech, Inc.

PII: S0091-6749(09)01144-0

doi:10.1016/j.jaci.2009.07.035

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