Asthma Control Test (ACT) Calculator

How to Use This Calculator

1. Select responses for all 5 ACT questions (each scored 1–5).
2. ACT total, control tier, and recommendation display instantly.
3. Childhood ACT tab: combined child (3 items) + parent (4 items) for ages 4–11.
4. GINA Criteria tab: 4-criterion binary assessment for comparison.
5. Professional tier adds GINA step and biologics threshold assessment.

Formula

Example

Frequently Asked Questions

• What is the Asthma Control Test (ACT)? ▼
  The Asthma Control Test (ACT) is a validated, patient-completed questionnaire developed by Nathan and colleagues and published in the Journal of Allergy and Clinical Immunology in 2004 to quantify asthma symptom control over the preceding four weeks. It consists of five questions, each scored on a 1–5 Likert scale, covering activity limitation due to asthma, frequency of shortness of breath, nocturnal symptoms, use of rescue (short-acting bronchodilator) medication, and the patient's own assessment of asthma control. Total ACT scores range from 5 (worst) to 25 (best). The ACT was developed to complement specialist-based assessments with a quick, inexpensive tool that patients can complete in under 2 minutes. It was validated against specialist assessments of asthma control according to NAEPP guidelines, with a score of 20 or greater corresponding to "well-controlled asthma" and a score of 15 or below indicating "poorly controlled asthma." The ACT has been translated into over 100 languages and is used in primary care, specialist practice, emergency departments, and clinical research worldwide. A separate 7-item Childhood ACT is validated for children aged 4–11, combining 3 child-answered and 4 parent-answered questions.
• What ACT score means well-controlled asthma? ▼
  An ACT score of 20 or above indicates well-controlled asthma based on the validation study by Nathan et al. which compared ACT scores to specialist assessments using NAEPP EPR-2 guideline criteria. A score of 20–25 corresponds to specialist-defined well-controlled or completely controlled asthma in most patients. Specifically, score 25 ("completely controlled") is achievable and should be the treatment goal for many patients. Scores in the range 16–19 indicate "not well-controlled" asthma — the patient has symptomatic asthma but not at the level classified as poorly controlled; these patients are candidates for assessment of inhaler technique, adherence, and trigger avoidance before step-up of pharmacotherapy. Scores ≤15 indicate "poorly controlled" asthma and warrant urgent clinical review, step-up therapy, and identification of contributing factors such as allergen exposure, NSAID/aspirin sensitivity, gastro-oesophageal reflux, vocal cord dysfunction, psychosocial stressors, and non-adherence. The minimal clinically important difference (MCID) for ACT is 3 points — meaning a change of at least 3 points between visits represents a clinically meaningful improvement or deterioration, not just measurement variability. ACT scores should be monitored at every clinical visit as a standard of care.
• How does ACT compare to GINA control criteria? ▼
  The ACT and the GINA (Global Initiative for Asthma) symptom control assessment are conceptually similar but mechanistically different. GINA uses four binary criteria assessed over the past 4 weeks: daytime symptoms more than twice per week, any nocturnal waking, SABA use for symptom relief more than twice per week, and any activity limitation. Patients are classified as well-controlled (0 criteria met), partly controlled (1–2 criteria), or uncontrolled (3–4 criteria). The ACT, by contrast, generates a continuous numerical score that allows granular tracking of changes over time. Studies comparing ACT to GINA show good concordance at extremes (ACT ≥20 correlates with GINA well-controlled; ACT ≤15 with GINA uncontrolled) but moderate agreement in the intermediate range. The ACT has several practical advantages: it is a patient-reported outcome tool standardised for clinical trials and quality improvement programmes; it enables tracking of minimal clinically important change (MCID = 3 points); and it captures self-perceived burden of disease alongside objective symptom frequency. GINA 2024 continues to recommend assessing control using a structured tool at every visit, with ACT being one of two recommended instruments (alongside the Asthma Control Questionnaire, ACQ-7). The two approaches are complementary rather than competing.
• When should asthma medication be stepped up based on ACT? ▼
  ACT score is one of several factors guiding decisions about stepping up asthma pharmacotherapy according to GINA guidelines. An ACT score below 20 (not well-controlled) at a scheduled review should prompt a structured assessment before automatically stepping up therapy: first confirm the diagnosis is correct; assess inhaler technique (suboptimal technique is responsible for poor control in 50–80% of cases); evaluate adherence to controller medication; identify and address modifiable triggers (allergen exposure, occupational sensitisers, NSAID use, smoking); and treat comorbidities that affect asthma control (rhinosinusitis, obesity, GERD, obstructive sleep apnoea). Only after these factors are addressed should pharmacotherapy be escalated. If ACT remains ≤19 despite optimised adherence and technique, step up therapy according to GINA steps: Step 2 to Step 3 involves adding a low-dose inhaled corticosteroid (ICS) or increasing ICS dose; Step 3 to Step 4 adds a long-acting beta-agonist (LABA) to ICS; Step 4 to Step 5 maximises ICS/LABA and adds a long-acting muscarinic antagonist (LAMA). For patients on Step 4–5 with ACT ≤15, consider biologic therapy (anti-IgE, anti-IL-5, anti-IL-4Rα) after confirming eosinophilic or allergic phenotype. Step-down should be considered after 3 consecutive months of ACT ≥20 at the lowest effective therapy level.
• Is the childhood ACT scored differently? ▼
  The Childhood Asthma Control Test (C-ACT), validated for children aged 4–11 years, uses a 7-item format that differs structurally from the adult ACT. It is a hybrid tool: children aged 4 and over answer 3 illustrated questions about how their asthma makes them feel, with picture-supported response options scored 0–3 (not 1–5 as in the adult version). Parents or caregivers answer 4 additional questions about observed asthma symptoms — daytime asthma days, daytime symptoms, nocturnal waking, and rescue inhaler use — using 5-level response scales scored 0–4. The total C-ACT score ranges from 0 to 27 (3 child × 3 points + 4 parent × 4 points, minus 1 for the minimum = 0 to 27). Scores ≥20 indicate well-controlled asthma; scores below 20 indicate uncontrolled asthma. Unlike the adult ACT which uses a three-tier cut-off, the C-ACT uses a single threshold of 20. The pictorial format makes it accessible to young children; the parent component ensures objective behavioural information complements the child's self-report. Research by Liu et al. validated the C-ACT with a sensitivity of 68% and specificity of 74% for identifying not-well-controlled asthma by specialist assessment. The adult ACT (5-item, score 5–25) is appropriate for patients 12 years and older.

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