Objective: The Asthma Control Test (ACT) consists of five items, one of which is self-assessment of asthma control. The goal of this study was to compare the responses to the first four ACT items with the response to the fifth item and determine whether this response affects the final ACT score.
Methods: Adult asthmatics (n = 417) were recruited from a specialty asthma center in Poland. Clinical data were collected by questionnaire. Spirometry and skin prick tests were performed for clinical evaluation. Asthma control was assessed through the ACT. The cutoff point for uncontrolled asthma was <20 points.
Results: Asthma was uncontrolled in 42.5% of patients. Based upon scores of the first four ACT items, three clusters of patients were identified. Cluster 1 comprised very well-controlled asthmatics [mean (sd) ACT total score 24.7 (0.7)]. Cluster 2 included both controlled and uncontrolled asthmatics [ACT total score 20.1 (2.5)]. Cluster 3 comprised poorly controlled asthmatics [ACT total score 12.1 (2.9)]. Misjudgment of asthma control in the fifth ACT item had no impact on the ACT total score in clusters 1 and 3. In cluster 2, the response to this item caused misclassification in 10.2% of patients.
Conclusions: In patients with either very well or very poorly controlled asthma, the response to the fifth ACT item did not alter the assignment into the appropriate asthma control group. Only in a small group of patients with a total ACT score of approximately 20 points did the asthma group classification result in either controlled or uncontrolled.
Keywords: Asthma Control Test; asthma control; asthma management; symptom perception.