Ana Sá-Sousa1, Ana Margarida Pereira2, Rute Almeida1, Luís Araújo3, Mariana Couto2, Tiago Jacinto4, Alberto Freitas5, Jean Bousquet6, João A Fonseca7. 1. CINTESIS-Center for Health Technology and Services Research, Faculdade de Medicina, Universidade do Porto, Porto, Portugal. 2. CINTESIS-Center for Health Technology and Services Research, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; MEDCIDS-Department of Community Medicine, Information, and Health Sciences, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Allergy Unit, Instituto & Hospital CUF Porto, Porto, Portugal. 3. MEDCIDS-Department of Community Medicine, Information, and Health Sciences, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Allergy Unit, Instituto & Hospital CUF Porto, Porto, Portugal; Immunology Department, Faculdade de Medicina da Universidade do Porto, Porto, Portugal. 4. CINTESIS-Center for Health Technology and Services Research, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Department of Cardiovascular and Respiratory Sciences, Escola Superior de Saúde, Politécnico do Porto, Porto, Portugal. 5. CINTESIS-Center for Health Technology and Services Research, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; MEDCIDS-Department of Community Medicine, Information, and Health Sciences, Faculdade de Medicina, Universidade do Porto, Porto, Portugal. 6. Centre Hospitalier Universitaire de Montpellier, Montpellier, France. 7. CINTESIS-Center for Health Technology and Services Research, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; MEDCIDS-Department of Community Medicine, Information, and Health Sciences, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Allergy Unit, Instituto & Hospital CUF Porto, Porto, Portugal. Electronic address: jfonseca@med.up.pt.
Abstract
BACKGROUND: One of the questions in epidemiology is the identification of adult asthma in studies. OBJECTIVE: To develop and validate multivariable scores for adult asthma identification in epidemiological studies and to explore cutoffs to rule in/rule out asthma, compared with asthma diagnosed by a physician after clinical examination and diagnostic tests, blinded to the self-administered questions. METHODS: We analyzed data (n = 711 adults) from a nationwide population-based study. The predictors were self-administered questions identified in a literature review (the Adult Asthma Epidemiological Score [A2 score]) and from the Global Allergy and Asthma Network of Excellence (GA2LEN) questionnaire (the GA2LEN Asthma Epidemiological Score [GA2LEN score]). Scores were developed using exploratory factor analysis. Internal consistency, discriminative power, and diagnostic accuracy were assessed. RESULTS: The A2 score comprises 8 questions (including "Did a physician confirm you had asthma?") and the GA2LEN score comprises 6 questions (including "Have you ever had asthma?"). Both had high Cronbach α (0.89 and 0.85, respectively, for the A2 score and the GA2LEN score) and good area under the receiver-operating characteristic curve (90.4% and 89.0%). The scoring is the sum of positive answers. Asthma is present (rule in) for scores of 4 or more (specificity, 99.2%; PPV, 93.3% and 91.7%; accuracy, 89.4% and 87.4%, respectively, for the A2 score and the GA2LEN score). Asthma is excluded (rule out) for A2 scores of 0 to 1 and a GA2LEN score of 0 (sensitivity, 93.1%; NPV, 98.2% and 98.0%; accuracy 89.4% and 82.8%, respectively, for the A2 score and the GA2LEN score). CONCLUSIONS: These practical scores can be used to rule in/rule out asthma in epidemiological studies and clinical screening/triage settings. They may help physicians in primary care or other specialties to screen patients with asthma using a simple score with a high level of discrimination and to identify the best candidates to be referred for a diagnostic workup. Moreover, their use may contribute to reducing the inconsistencies of operational definitions of asthma across studies and surveys.
BACKGROUND: One of the questions in epidemiology is the identification of adult asthma in studies. OBJECTIVE: To develop and validate multivariable scores for adult asthma identification in epidemiological studies and to explore cutoffs to rule in/rule out asthma, compared with asthma diagnosed by a physician after clinical examination and diagnostic tests, blinded to the self-administered questions. METHODS: We analyzed data (n = 711 adults) from a nationwide population-based study. The predictors were self-administered questions identified in a literature review (the Adult Asthma Epidemiological Score [A2 score]) and from the Global Allergy and Asthma Network of Excellence (GA2LEN) questionnaire (the GA2LEN Asthma Epidemiological Score [GA2LEN score]). Scores were developed using exploratory factor analysis. Internal consistency, discriminative power, and diagnostic accuracy were assessed. RESULTS: The A2 score comprises 8 questions (including "Did a physician confirm you had asthma?") and the GA2LEN score comprises 6 questions (including "Have you ever had asthma?"). Both had high Cronbach α (0.89 and 0.85, respectively, for the A2 score and the GA2LEN score) and good area under the receiver-operating characteristic curve (90.4% and 89.0%). The scoring is the sum of positive answers. Asthma is present (rule in) for scores of 4 or more (specificity, 99.2%; PPV, 93.3% and 91.7%; accuracy, 89.4% and 87.4%, respectively, for the A2 score and the GA2LEN score). Asthma is excluded (rule out) for A2 scores of 0 to 1 and a GA2LEN score of 0 (sensitivity, 93.1%; NPV, 98.2% and 98.0%; accuracy 89.4% and 82.8%, respectively, for the A2 score and the GA2LEN score). CONCLUSIONS: These practical scores can be used to rule in/rule out asthma in epidemiological studies and clinical screening/triage settings. They may help physicians in primary care or other specialties to screen patients with asthma using a simple score with a high level of discrimination and to identify the best candidates to be referred for a diagnostic workup. Moreover, their use may contribute to reducing the inconsistencies of operational definitions of asthma across studies and surveys.