The Journal of Allergy and Clinical Immunology
Volume 117, Issue 3 , Pages 549-556, March 2006

Asthma Control Test: Reliability, validity, and responsiveness in patients not previously followed by asthma specialists

  • Michael Schatz, MD, MS

      Affiliations

    • From Kaiser-Permanente Medical Center, San Diego
    • Corresponding Author InformationReprint requests: Michael Schatz, MD, MS, Kaiser-Permanente Medical Center, 7060 Clairemont Mesa Blvd, San Diego, CA 92111.
    • ,
  • Christine A. Sorkness, PharmD

      Affiliations

    • University of Wisconsin School of Pharmacy, Madison
    • ,
  • James T. Li, MD, PhD

      Affiliations

    • Mayo Medical Center, Rochester
    • ,
  • Philip Marcus, MD, MPH

      Affiliations

    • Nassau Chest Physicians, PC, Great Neck
    • ,
  • John J. Murray, MD, PhD

      Affiliations

    • Vanderbilt Asthma Sinus Allergy Program, Nashville
    • ,
  • Robert A. Nathan, MD

      Affiliations

    • Asthma and Allergy Associates and Research Center, Colorado Springs
    • ,
  • Mark Kosinski, MA

      Affiliations

    • QualityMetric, Incorporated, Lincoln
    • ,
  • Trudy B. Pendergraft, MSPH

      Affiliations

    • GlaxoSmithKline, Research Triangle Park
    • ,
  • Priti Jhingran, PhD

      Affiliations

    • GlaxoSmithKline, Research Triangle Park

Received 6 July 2005; received in revised form 22 December 2005; accepted 4 January 2006.

San Diego, Calif, Madison, Wis, Rochester, Minn, Great Neck, NY, Nashville, Tenn, Colorado Springs, Colo, Lincoln, RI, and Research Triangle Park, NC

Background

The development of the Asthma Control Test (ACT), a short, simple, patient-based tool for identifying patients with poorly controlled asthma, was recently described in patients under the routine care of an asthma specialist.

Objectives

We sought to evaluate the reliability and validity of the ACT in a longitudinal study of asthmatic patients new to the care of an asthma specialist.

Methods

Patients (n = 313) completed the ACT and the Asthma Control Questionnaire (ACQ) at 2 physician visits (4-12 weeks apart). Pulmonary function was measured, and asthma specialists rated asthma control.

Results

Internal consistency reliability of the ACT was 0.85 (baseline) and 0.79 (follow-up). Test-retest reliability was 0.77. Criterion validity was demonstrated by significant correlations between baseline ACT scores and baseline specialists' ratings of asthma control (r = 0.52, P < .001) and ACQ scores (r = −0.89, P < .001). Discriminant validity was demonstrated, with significant (P < .001) differences in mean ACT scores across patients differing in asthma control, pulmonary function, and treatment recommendation. Responsiveness of the ACT to changes in asthma control and lung function was demonstrated with significant correlations between changes in ACT scores and changes in specialists' ratings (r = 0.44, P < .001), ACQ scores (r = −0.69, P < .001), and percent predicted FEV1 values (r = 0.29, P < .001). An ACT score of 19 or less provided optimum balance of sensitivity (71%) and specificity (71%) for detecting uncontrolled asthma.

Conclusions

The ACT is reliable, valid, and responsive to changes in asthma control over time in patients new to the care of asthma specialists. A cutoff score of 19 or less identifies patients with poorly controlled asthma.

Clinical implications

In a clinical setting the ACT should be a useful tool to help physicians identify patients with uncontrolled asthma and facilitate their ability to follow patients' progress with treatment.

Key words: Asthma control assessment, Asthma Control Test

Abbreviations used: ACQ, Asthma Control Questionnaire, ACT, Asthma Control Test, NAEPP, National Asthma Education and Prevention Program, ROC, Receiver operating characteristic

 

 The research described in this article was funded by GlaxoSmithKline.Disclosure of potential conflict of interest: M. Schatz has received grants–research support from GlaxoSmithKline and Sanofi-Aventis and is on the speakers' bureau for AstraZeneca and Merck. C. A. Sorkness has consultant arrangements with GlaxoSmithKline and AstraZeneca, has received grants–research support from GlaxoSmithKline, and is on the speakers' bureau for GlaxoSmithKline and Genentech. J. T. Li has had consultant arrangements with GlaxoSmithKline and has received grants–research support from GlaxoSmithKline. P. Marcus has consultant arrangements with Altana, has received grants–research support from GlaxoSmithKline and AstraZeneca, and is on the speakers' bureau for GlaxoSmithKline, Genentech, Novarits, Merck, and Aventis. J. J. Murray has consultant arrangements with GlaxoSmithKline, has received grants–research support from GlaxoSmithKline, and is on the speakers' bureau for GlaxoSmithKline. R. A. Nathan has consultant arrangements with Amgen, Altana, AstraZeneca, Aventis, Genentech, GlaxoSmithKline, Merck, Novartis, Pfizer, Schering/Key, Sepracor, and Viropharm; has received grants–research support from Abbot, Altana, Aventis, AstraZeneca, Bayer, Berlex, Boehringer Ingelheim, Bristol-Myers Squibb, Ciba-Geigy, Dura, Forest, GlaxoSmithKline, Immunex, Janssen, Parke-Davis, Pfizer, 3-M Pharmaceuticals, Proctor & Gamble, Roberts, Sandoz, Sanofi, Schering/Key, Sepracor, Sterling, Tap Pharmaceuticals, Wallace, and Wyeth; and is on the speakers' bureau for AstraZeneca, Aventis, Genentech/Novartis, GlaxoSmithKline, Pfizer, and Schering/Key. M. Kosinski—none declared. T. B. Pendergraft is employed by GlaxoSmithKline. P. Jhingran has stock or other equity ownership in and is employed by GlaxoSmithKline.

PII: S0091-6749(06)00174-6

doi:10.1016/j.jaci.2006.01.011

The Journal of Allergy and Clinical Immunology
Volume 117, Issue 3 , Pages 549-556, March 2006

Article Tools

* Image Usage & Resolution