Detection of exacerbations in asthma based on electronic diary data: results from the 1-year prospective BIOAIR study

• Published in: Thorax Vol. 68; no. 7; pp. 611 - 618
• Main Authors: Kupczyk, Maciej, Haque, Shushila, Sterk, Peter J, Niżankowska-Mogilnicka, Ewa, Papi, Alberto, Bel, Elisabeth H, Chanez, Pascal, Dahlén, Barbro, Gaga, Mina, Gjomarkaj, Mark, Howarth, Peter H, Johnston, Sebastian L, Joos, Guy F, Kanniess, Frank, Tzortzaki, Eleni, James, Anna, Middelveld, Roelinde J M, Dahlén, Sven-Erik
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 01.07.2013
• Subjects: Administration, Inhalation; Adolescent; Adult; Aged; Asthma; Asthma - diagnosis; Asthma - drug therapy; Asthma - physiopathology; Biomarkers; Bronchodilator Agents - administration & dosage; Bronchodilator Agents - therapeutic use; Budesonide - administration & dosage; Budesonide - therapeutic use; Clinical trials; Cross-Over Studies; Diaries; Disease Progression; Drug Therapy, Combination; Electronic Health Records - statistics & numerical data; Emergency medical care; Female; Follow-Up Studies; Forced Expiratory Volume; Glucocorticoids - therapeutic use; Humans; Male; Medicin och hälsovetenskap; Middle Aged; Patients; Peak Expiratory Flow Rate; Prognosis; Prospective Studies; Quality of Life; Questionnaires; Sensitivity and Specificity; Steroids; Surveys and Questionnaires; Time Factors; Young Adult; Respiratory Measurement; Asthma Guidelines; Asthma
• ISSN: 0040-6376; 1468-3296; 1468-3296
• DOI: 10.1136/thoraxjnl-2012-201815

Background Objective measures are required that may be used as a proxy for exacerbations in asthma. The aim was to determine the sensitivity and specificity of electronic diary data to detect severe exacerbations (SEs) of asthma. A secondary aim was to identify phenotypic variables associated with a higher risk of exacerbation. Methods In the BIOAIR study, 169 patients with asthma (93 severe (SA); 76 mild to moderate (MA)) recorded lung function, symptoms and medication use in electronic diaries for 1 year. Data were analysed using receiver-operator characteristics curves and related to physician-diagnosed exacerbations. Medical history and baseline clinical data were used to assess risk of exacerbation. Results Of 122 physician-diagnosed exacerbations, 104 occurred in the SA group (1.1 per patient/year), 18 in the MA group (0.2 per patient/year) and 63 were severe using American Thoracic Society/European Respiratory Society criteria. During exacerbations, peak expiratory flow (PEF) and forced expiratory volume in 1 s significantly decreased, whereas day and night symptoms significantly increased. An algorithm combining a 20% decrease in PEF or a 20% increase in day symptoms on 2 consecutive days was able to detect SEs with 65% sensitivity and 95% specificity. The strongest risk factors for SEs were low Asthma Control Questionnaire score, sputum eosinophils ≥3%, body mass index >25 and low quality of life (St George's Respiratory Questionnaire), with ORs between 3.61 and 2.22 (p<0.05). Conclusions Regular electronic monitoring of PEF and asthma symptoms provides an acceptable sensitivity and specificity for the detection of SEs and may be suitable for personal internet-based monitoring of asthma control.