BACKGROUND: Weak and inconsistent correlations between measurements of asthma health status suggest that the disease is composed of nonoverlapping components. OBJECTIVE: Factor analysis was used to explore the relationships between measures of asthma morbidity and to identify heterogeneous components of asthma health status in children 5 to 12 years old. Results were compared across time (baseline and 48-month visit) and treatment arms. METHODS: Analyses were conducted in 7 different study windows in a database from a large clinical trial of children with mild to moderate asthma (n = 1041). Measurements of lung function, symptoms, and health care utilization from daily diary cards, serum IgE levels, total eosinophil count, skin test positivity, and airway hyperresponsiveness were included. Data on fractional exhaled nitric oxide and sputum eosinophil cationic protein were included in a subgroup of patients. RESULTS: In each of the study windows, factor analysis identified 5 factors that explained between 50% and 60% of the common variance. Factors identified included (1) inflammatory markers, (2) symptoms/medication use, (3) asthma exacerbations, and measures of lung function, which subdivided into (4) FEV(1) and forced vital capacity, and (5) bronchodilator response and the FEV(1)/forced vital capacity ratio. Exploratory analyses suggest that fractional exhaled nitric oxide account for the atopy/inflammatory marker factor, and sputum measurements account for a sixth, separate factor. CONCLUSION: The consistent identification of a 5-factor structure across time and treatment arms suggests that each of these factors provides independent information in the assessment of asthma.
BACKGROUND: Weak and inconsistent correlations between measurements of asthma health status suggest that the disease is composed of nonoverlapping components. OBJECTIVE: Factor analysis was used to explore the relationships between measures of asthma morbidity and to identify heterogeneous components of asthma health status in children 5 to 12 years old. Results were compared across time (baseline and 48-month visit) and treatment arms. METHODS: Analyses were conducted in 7 different study windows in a database from a large clinical trial of children with mild to moderate asthma (n = 1041). Measurements of lung function, symptoms, and health care utilization from daily diary cards, serum IgE levels, total eosinophil count, skin test positivity, and airway hyperresponsiveness were included. Data on fractional exhaled nitric oxide and sputum eosinophil cationic protein were included in a subgroup of patients. RESULTS: In each of the study windows, factor analysis identified 5 factors that explained between 50% and 60% of the common variance. Factors identified included (1) inflammatory markers, (2) symptoms/medication use, (3) asthma exacerbations, and measures of lung function, which subdivided into (4) FEV(1) and forced vital capacity, and (5) bronchodilator response and the FEV(1)/forced vital capacity ratio. Exploratory analyses suggest that fractional exhaled nitric oxide account for the atopy/inflammatory marker factor, and sputum measurements account for a sixth, separate factor. CONCLUSION: The consistent identification of a 5-factor structure across time and treatment arms suggests that each of these factors provides independent information in the assessment of asthma.
Authors: Finn Rasmussen; D Robin Taylor; Erin M Flannery; Jan O Cowan; Justina M Greene; G Peter Herbison; Malcolm R Sears Journal: J Allergy Clin Immunol Date: 2002-08 Impact factor: 10.793
Authors: J K Sont; L N Willems; E H Bel; J H van Krieken; J P Vandenbroucke; P J Sterk Journal: Am J Respir Crit Care Med Date: 1999-04 Impact factor: 21.405
Authors: Paul J Sharek; Michelle L Mayer; Lisa Loewy; Thomas N Robinson; Richard S Shames; Dale T Umetsu; David A Bergman Journal: Pediatrics Date: 2002-10 Impact factor: 7.124
Authors: Erick Forno; Anne Fuhlbrigge; Manuel E Soto-Quirós; Lydiana Avila; Benjamin A Raby; John Brehm; Jody M Sylvia; Scott T Weiss; Juan C Celedón Journal: Chest Date: 2010-05-14 Impact factor: 9.410
Authors: Sze Man Tse; Diane R Gold; Joanne E Sordillo; Elaine B Hoffman; Matthew W Gillman; Sheryl L Rifas-Shiman; Anne L Fuhlbrigge; Kelan G Tantisira; Scott T Weiss; Augusto A Litonjua Journal: J Allergy Clin Immunol Date: 2013-05-14 Impact factor: 10.793
Authors: Vicente Plaza; David Ramos-Barbón; Ana María Muñoz; Ana María Fortuna; Astrid Crespo; Cristina Murio; Rosa Palomino Journal: PLoS One Date: 2013-10-25 Impact factor: 3.240