Printed on 3/17/2026
For informational purposes only. This is not medical advice.
The ACT is a 5-item patient-completed questionnaire assessing activity limitation, shortness of breath, nighttime symptoms, rescue inhaler use, and self-rated control over the past 4 weeks. Scores ≥20 indicate well-controlled asthma; scores <16 indicate very poorly controlled asthma.
Formula: Sum of 5 items (each 1–5). Total: 5–25. Well controlled ≥20, Not well controlled 16–19, Very poorly controlled ≤15.
Your Asthma Control Test (ACT) score reflects how well your asthma has been controlled over the past 4 weeks. A score of 20–25 indicates well-controlled asthma, meaning your current treatment regimen is working effectively and you are experiencing minimal symptoms, few activity limitations, and little need for rescue medications. A score of 16–19 indicates not well-controlled asthma, suggesting your treatment may need to be stepped up or adherence and inhaler technique reassessed. A score of 15 or below indicates very poorly controlled asthma, which warrants urgent clinical evaluation and likely a significant change in management.
A change of 3 or more points on the ACT is considered the minimal clinically important difference (MCID), meaning it represents a real and meaningful change in asthma control rather than random variation. Tracking your score over time helps identify trends and the impact of treatment adjustments.
Use the ACT at every asthma follow-up visit, typically every 1–6 months, as recommended by GINA (Global Initiative for Asthma) and NAEPP (National Asthma Education and Prevention Program) guidelines. It serves as a standardized, patient-reported measure that helps clinicians make step-up or step-down therapy decisions based on recent symptom control rather than relying solely on spirometry or clinical impression.
The ACT is also valuable for patient self-monitoring between clinic visits. Patients who notice a declining score can seek medical attention before a serious exacerbation occurs. It is validated for use in adults and adolescents aged 12 and older; the Childhood ACT (C-ACT) is available for children aged 4–11.
The ACT is a patient-reported outcome measure and is subject to recall bias and subjective interpretation of symptom severity. Patients may overestimate or underestimate their level of control depending on their expectations, health literacy, and tolerance of symptoms. It does not replace objective measures of lung function such as spirometry (FEV1) or peak expiratory flow, which may reveal airflow obstruction even when symptoms are perceived as well-controlled.
The ACT does not assess exacerbation risk factors such as blood eosinophil count, FeNO levels, allergen exposure, medication adherence, or inhaler technique. A patient can have a well-controlled ACT score yet remain at high risk for future exacerbations due to persistent airway inflammation. Additionally, the ACT was validated for chronic persistent asthma and may not accurately reflect control in patients with intermittent asthma, exercise-induced bronchoconstriction, or occupational asthma.
For related assessments, see COPD GOLD, P/F Ratio and FiO₂ Conversion.
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
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