Asthma Control Questionnaire
Also known as: ACQ, Asthma Control Q
The ACQ is a 7-item self-report questionnaire developed by Juniper and colleagues at McMaster University in 1999 to assess the degree of asthma control in the previous one to two weeks. Unlike generic respiratory tools, the ACQ measures symptom-based control and rescue medication use, providing a simple yet psychometrically sound method for evaluating treatment efficacy. It is widely adopted in clinical trials, guideline-driven care, and routine asthma management to guide therapy titration and assess treatment response.
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When to use it
The ACQ is indicated for patients with persistent asthma (intermittent asthma may show floor effects). It is ideal in clinical trials to measure treatment response, in primary care and specialty asthma clinics to guide step-up/step-down decisions, and in chronic disease management programs to assess control trajectory. The ACQ is less useful for acute asthma exacerbation assessment or in patients with asthma exacerbations occurring <1 week prior (recent events may artificially elevate scores).
Strengths & limitations
- Brevity: 7 items require only 2–3 minutes, enhancing feasibility in busy clinical settings
- Objective and subjective hybrid: Combines symptom reports with rescue medication use (objective proxy for control), reducing pure self-report bias
- Well-established cutoffs: Clear threshold interpretations (≤0.75 = controlled) facilitate straightforward clinical decisions
- Responsive to change: Sensitive to treatment effects; changes of 0.5 units reliably signal clinically meaningful improvement or deterioration
- Recall period dependency: Assesses 'past 1–2 weeks'; longer-term asthma control patterns may be obscured
- Floor effects in controlled asthma: Highly controlled patients may consistently score ≤0.5, leaving limited room to detect further improvement
- FEV₁ requirement in ACQ-7: The standard version includes baseline spirometry; ACQ-6 (without FEV₁) may be preferable when spirometry is unavailable
Frequently asked
What is the difference between ACQ-7, ACQ-6, and ACQ-5?
ACQ-7 includes all five symptoms plus rescue medication use plus baseline FEV₁ (clinician-measured). ACQ-6 omits FEV₁ (patient or clinician-reported). ACQ-5 includes only the five symptom items. All three have valid cutoffs; choice depends on whether spirometry is available and time constraints.
A patient scores 0.9 on the ACQ; is their asthma controlled?
A score of 0.9 falls in the 'intermediate control' range (0.75–1.5). While not in the 'well-controlled' range (≤0.75), it does not meet the threshold for poor control (>1.5). Clinical context matters: if baseline was >1.5, this represents improvement; if the goal is tighter control, treatment adjustment may be warranted.
How sensitive is the ACQ to seasonal or irregular asthma?
The ACQ's 1–2-week recall period captures recent control but may not reflect year-round patterns in seasonal asthma. Repeat measurements across seasons or extended recall versions may better characterize seasonal patterns.
Should I use ACQ or a generic questionnaire like SF-36 for asthma?
Use ACQ for asthma control monitoring and treatment decisions. ACQ is more sensitive and specific to asthma control. Use generic tools like SF-36 when broader health-related quality of life is relevant (e.g., asthma impact on work/social function) alongside ACQ for a complete picture.
Sources
- Juniper, E. F., O'Byrne, P. M., Guyatt, G. H., Ferrie, P. J., & King, D. R. (1999). Development and validation of a questionnaire to measure asthma control. European Respiratory Journal, 14(4), 902-907. DOI: 10.1034/j.1399-3003.1999.14d29.x ↗
- Juniper, E. F., Svensson, K., Mörk, A. C., & Ståhl, E. (2005). Measurement properties and interpretation of three shortened versions of the asthma control questionnaire. Respiratory Medicine, 99(5), 553-558. DOI: 10.1016/j.rmed.2004.10.008 ↗
How to cite this page
ScholarGate. (2026, June 3). Asthma Control Questionnaire. ScholarGate. https://scholargate.app/en/pulmonology/asthma-control-questionnaire
Which method?
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