Incidence of chronic obstructive pulmonary disease based on three spirometric diagnostic criteria in Sao Paulo, Brazil: a nine-year follow-up since the PLATINO prevalence study

Abstract

CONTEXT AND OBJECTIVE: Chronic obstructive pulmonary disease (COPD) is a respiratory disease of high prevalence and socioeconomic impact worldwide. It affects approximately 16% of the population of São Paulo. The incidence of COPD is still unknown in Brazil. The aim of this study was to estimate new cases of COPD in a population-based sample in São Paulo, Brazil, using three different spirometric diagnostic criteria, and to assess the concordance between these criteria.DESIGN AND SETTING: Prospective cohort study, in the city of São Paulo, Brazil.METHODS: A questionnaire was applied and anthropometry and pre and post-bronchodilator spirometry were performed on the same subjects as in the initial PLATINO study (2003) in São Paulo. Data from this follow-up study were added to the original database of the initial phase. Incident COPD cases refer to subjects who developed the disease in accordance with each spirometric criterion during the nine-year follow-up period. The Statistical Package for the Social Sciences, version 17.0 (SPSS Inc., Chicago, IL, USA) was used in the analysis and the significance level was set at P < 0.05.RESULTS: 613 subjects participated in the follow-up. New COPD cases ranged in frequency from 1.4% to 4.0%, depending on the diagnostic criterion used. The concordance between the criteria ranged from 35% to 60%.CONCLUSION: The incidence of COPD after a nine-year follow-up was high, but varied according to the spirometric criterion used. The agreement between the criteria for identifying new cases of the disease ranged from 35% to 60%.

Does the COPD assessment test reflect functional status in patients with COPD?

“…Because COPD is a systemic disease with multidimensional approach, 1,36 the spirometric GOLD classification is not strongly associated with functional status, 37,38 reinforcing the importance of the inclusion of clinical outcomes in COPD classification other than lung function or the use of the A–B–C–D classification. It should be pointed out that the multidimensional classification does not take functional status into account, only the association between lung function and symptoms.…”

Joint Indian Chest Society-National College of Chest Physicians (India) guidelines for spirometry

“…Different exclusion criteria have been followed in large epidemiological studies in which spirometry was performed. [147148] Some of the conditions which may preclude spirometry are listed in Table 5.…”

Controversies and Limitations in the Diagnosis of Chronic Obstructive Pulmonary Disease

“…In the general population, there is an enormous underdiagnosis of COPD that can rise to 90% when the spirometry definition is used 39 . The number of spirometry tests conducted in primary care has increased very little, even in developed countries, and in some reports, in only 12.2% of patients with clinical symptoms suggestive of COPD, a spirometry is performed to confirm the diagnosis [40][41][42] .…”