Internet diaries and the asthma control test in children with asthma

Published Online: December 3, 2013

Symptom diaries are frequently used to assess asthma control in asthma studies. Such diaries can be paper-based, or available on the internet. Data on the validity of web-based diaries are scarce. The asthma control test (ACT) and childhood asthma control test (C-ACT, for children under the age of 12) are questionnaires which are developed and validated for detection of uncontrolled asthma and only few studies have proposed a cut-off point for well-controlled asthma. Also the minimal important difference in C-ACT and ACT score that reflects a clinically meaningful change for the patient is unknown.

In an original article recently published in The Journal of Allergy and Clinical Immunology (JACI), Voorend-van Bergen et al studied the validity of a web-based diary in assessing asthma control in children, using the ACT as gold standard. Also, the authors determined cut-off points for well-controlled asthma of the C-ACT and ACT, and calculated the minimal important difference for both tests based on changes in quality of life.

The researchers found a very high completion rate of 89% for the web-based diaries. The diary data of 228 asthmatic children correlated strongly with their ACT scores and also with changes in C-ACT or ACT and changes in asthma related quality of life. Therefore Voorend-van Bergen et al concluded that web-based diaries are feasible and valid for use in clinical research. Also, the authors defined cut-off points for well-controlled asthma as C-ACT ≥ 22 and ACT ≥ 23 and they recommended a difference of  2 C-ACT or ACT points as minimally important.


The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

AAAAI - American Academy of Allergy Asthma & Immunology