ABSTRACT
ABSTRACT BACKGROUND: Asthma is a chronic inflammatory disease with airway hyperresponsiveness. Spirometry is the most commonly used test among asthmatic patients. Another functional test used for diagnosing asthma is the bronchial challenge test. The aim of this study was to analyze the accuracy of spirometry for detecting asthma in the general population. DESIGN AND SETTING: Cross-sectional study with data analysis to evaluate the accuracy of spirometry through calculating sensitivity, specificity and predictive values and through the kappa agreement test. METHODS: Subjects who constituted a birth cohort were enrolled at the age of 23 to 25 years. Spirometric abnormality was defined as reduced forced expiratory volume in one second, i.e. lower than 80% of the predicted value. Measurement of bronchial responsiveness was performed by means of the bronchial challenge test with methacholine. The gold-standard diagnosis of asthma was defined as the presence of bronchial hyperresponsiveness in association with respiratory symptoms. RESULTS: Asthma was detected in 200 subjects (10.4%) out of the sample of 1922 individuals. Spirometric abnormality was detected in 208 subjects (10.9%) of the sample. The specificity of spirometric abnormality for detecting asthma was 90%, sensitivity was 23%, positive predictive value was 22%, and negative predictive value was 91%. The kappa test revealed weak agreement of 0.13 (95% confidence interval, CI: 0.07-0.19) between spirometry and the diagnosis of asthma. CONCLUSION: Spirometry, as a single test, has limitations for detecting asthma in the general population.
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Young Adult , Asthma/diagnosis , Spirometry , Asthma/epidemiology , Brazil/epidemiology , Bronchial Provocation Tests , Cross-Sectional Studies , Predictive Value of Tests , Bronchoconstrictor Agents , Methacholine Chloride , Sensitivity and SpecificityABSTRACT
OBJETIVO: Avaliar a compreensão e a técnica de uso dos dispositivos inalatórios prescritos de pacientes com asma ou DPOC atendidos em um hospital-escola terciário. MÉTODOS: Os pacientes foram avaliados na sala de pós-consulta sem que o médico soubesse do estudo. Foi solicitado que o paciente demonstrasse como utiliza a medicação inalatória e, em seguida, esse foi entrevistado sobre a compreensão dos dispositivos inalatórios, controle da doença e orientações recebidas durante as consultas. RESULTADOS: Foram avaliados 120 voluntários: 60 asmáticos e 60 com DPOC. Todos os asmáticos e 98,3 por cento do grupo DPOC relataram saber utilizar os medicamentos inalatórios. Na amostra como um todo, 113 pacientes (94,2 por cento) cometeram pelo menos um erro ao utilizar o dispositivo inalatório. Os pacientes cometeram mais erros ao utilizar aerossol dosimetrado do que ao utilizar os inaladores de pó seco Aerolizer® (p < 0,001) ou Pulvinal® (p < 0,001), assim como mais erros ao utilizar Aerolizer® do que ao utilizar Pulvinal® (p < 0,05). O grupo DPOC cometeu significativamente mais erros que o grupo asma ao utilizar o aerossol dosimetrado (p = 0,0023), Pulvinal® (p = 0,0065) e Aerolizer® (p = 0,012). CONCLUSÕES: Embora a maioria dos pacientes relatasse saber a técnica adequada de utilização dos dispositivos inalatórios, 94,2 por cento cometeu pelo menos um erro na utilização dos dispositivos, demonstrando técnica insatisfatória e discrepância entre a compreensão e a prática. Portanto, apenas questionar os pacientes sobre o uso dos dispositivos inalatórios não é suficiente. Medidas práticas devem ser tomadas a fim de diminuir os erros e otimizar a terapêutica.
OBJECTIVE: To evaluate knowledge of and techniques for using prescribed inhalation devices among patients with asthma or COPD treated at a tertiary teaching hospital. METHODS: Patients were assessed after medical visits, and their physicians were blinded to this fact. Patients were asked to demonstrate their inhaler technique and were then interviewed regarding their knowledge of inhalation devices, control of the disease and instructions received during medical visits. RESULTS: We included 120 volunteers: 60 with asthma and 60 with COPD. All of the asthma patients and 98.3 percent of the COPD patients claimed to know how to use inhaled medications. In the sample as a whole, 113 patients (94.2 percent) committed at least one error when using the inhalation device. Patients committed more errors when using metered-dose inhalers than when using the dry-powder inhalers Aerolizer® (p < 0.001) or Pulvinal® (p < 0.001), as well as committing more errors when using the Aerolizer® inhaler than when using the Pulvinal® inhaler (p < 0.05). Using the metered-dose, Pulvinal® and Aerolizer® inhalers, the COPD group patients committed more errors than did the asthma group patients (p = 0.0023, p = 0.0065 and p = 0.012, respectively). CONCLUSIONS: Although the majority of the patients claimed to know how to use inhalation devices, the fact that 94.2 percent committed at least one error shows that their technique was inappropriate and reveals a discrepancy between understanding and practice. Therefore, it is not sufficient to ask patients whether they know how to use inhalation devices. Practical measures should be taken in order to minimize errors and optimize treatment.