Trajectories of Spirometric Patterns, Obstructive and PRISm, in a Population-Based Cohort in Latin America.

Background: Preserved ratio impaired spirometry (PRISm) has been associated with adverse outcomes and increased transition to other spirometric categories over time. We aimed to examine its prevalence, trajectories over time, and outcomes in a population-based sample from Latin America. Methods: Data were obtained from two population-based surveys of adults from three cities in Latin America (PLATINO study), conducted on the same individuals 5-9 years after their baseline examination. We estimated the frequency of PRISm defined by FEV1/FVC≥0.70 with FEV1 <80%, describing their clinical characteristics, longitudinal transition trajectories over time, factors associated with the transition. Results: At baseline, 2942 participants completed post-bronchodilator spirometry, and 2026 at both evaluations. The prevalence of normal spirometry was 78%, GOLD-stage 1 10.6%, GOLD 2-4 6.5%, and PRISm was: 5.0% (95% CI 4.2-5.8). PRISm was associated with less schooling, more reports of physician-diagnosis of COPD, wheezing, dyspnea, missing days at work, having ≥2 exacerbations in the previous year but without accelerated lung function decline. Mortality risk was significantly higher in PRISm (HR 1.97, 95% CI 1.2-3.3) and COPD GOLD 1-4 categories (HR 1.79, 95% CI 1.3-2.4) compared with normal spirometry. PRISm at baseline most frequently transitioned to another category at follow-up (46.5%); 26.7% to normal spirometry and 19.8% to COPD. The best predictors of transition to COPD were closeness of FEV1/FVC to 0.70, older age, current smoking, and a longer FET in the second assessment. Conclusion: PRISm, is a heterogeneous and unstable condition prone to adverse outcomes that require adequate follow-up.

Outcomes for symptomatic non-obstructed individuals and individuals with mild (GOLD stage 1) COPD in a population based cohort.

BACKGROUND: We aimed to study the adverse outcomes of symptomatic and asymptomatic non-obstructed individuals and those with mild COPD longitudinally in participants from three Latin-American cities. METHODS: Two population-based surveys of adults with spirometry were conducted for these same individuals with a 5- to 9-year interval. We evaluated the impact of respiratory symptoms (cough, phlegm, wheezing or dyspnea) in non-obstructed individuals, and among those classified as Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 1, COPD on exacerbation frequency, mortality and FEV1 decline, compared with asymptomatic individuals without airflow obstruction or restriction. RESULTS: Non-obstructed symptomatic individuals had a marginal increased risk of mortality (HR 1.3; 95% CI 0.9-1.94), increased FEV1 decline (-4.5 mL/year; 95% CI -8.6, -0.4) and increased risk of 2+ exacerbations in the previous year (OR 2.6; 95% CI 1.2-6.5). Individuals with GOLD stage 1 had a marginal increase in mortality (HR 1.5; 95% CI 0.93-2.3) but a non-significant impact on FEV1 decline or exacerbations compared with non-obstructed individuals. CONCLUSIONS: The presence of respiratory symptoms in non-obstructed individuals was a predictor of mortality, lung-function decline and exacerbations, whereas the impact of GOLD stage 1 was mild and inconsistent. Respiratory symptoms were associated with asthma, current smoking, and the report of heart disease. Spirometric case-finding and treatment should target individuals with moderate-to-severe airflow obstruction and those with restriction, the groups with consistent increased mortality.

Instability in the COPD diagnosis upon repeat testing vary with the definition of COPD.

BACKGROUND: A low FEV1/FVC from post-bronchodilator spirometry is required to diagnose COPD. Both the FEV1 and the FVC can vary over time; therefore, individuals can be given a diagnosis of mild COPD at one visit, but have normal spirometry during the next appointment, even without an intervention. METHODS: We analyzed two population-based surveys of adults with spirometry carried out for the same individuals 5-9 years after their baseline examination. We determined the factors associated with a change in the spirometry interpretation from one exam to the next utilizing different criteria commonly used to diagnose COPD. RESULTS: The rate of an inconsistent diagnosis of mild COPD was 11.7% using FEV1/FVC <0.70, 5.9% using FEV1/FEV6

Assessment of five different guideline indication criteria for spirometry, including modified GOLD criteria, in order to detect COPD: data from 5,315 subjects in the PLATINO study.

BACKGROUND: Spirometry is the gold standard for diagnosing chronic obstructive pulmonary disease (COPD). Although there are a number of different guideline criteria for deciding who should be selected for spirometric screening, to date it is not known which criteria are the best based on sensitivity and specificity. AIMS: Firstly, to evaluate the proportion of subjects in the PLATINO Study that would be recommended for spirometry testing according to Global initiative for Obstructive Lung Disease (GOLD)-modified, American College of Chest Physicians (ACCP), National Lung Health Education Program (NLHEP), GOLD and American Thoracic Society/European Respiratory Society (ATS/ERS) criteria. Secondly, we aimed to compare the sensitivity, specificity, and positive predictive and negative predictive values, of these five different criteria. METHODS: Data from the PLATINO study included information on respiratory symptoms, smoking and previous spirometry testing. The GOLD-modified spirometry indication criteria are based on three positive answers out of five questions: the presence of cough, phlegm in the morning, dyspnoea, age over 40 years and smoking status. RESULTS: Data from 5,315 subjects were reviewed. Fewer people had an indication for spirometry (41.3%) according to the GOLD-modified criteria, and more people had an indication for spirometry (80.4%) by the GOLD and ATS/ERS criteria. A low percentage had previously had spirometry performed: GOLD-modified (14.5%); ACCP (13.2%); NLHEP (12.6%); and GOLD and ATS/ERS (12.3%). The GOLD-modified criteria showed the least sensitivity (54.9) and the highest specificity (61.0) for detecting COPD, whereas GOLD and ATS/ERS criteria showed the highest sensitivity (87.9) and the least specificity (20.8). CONCLUSION: There is a considerable difference in the indication for spirometry according to the five different guideline criteria. The GOLD-modified criteria recruit less people with the greatest sum of sensitivity and specificity.

The chronic bronchitis phenotype in subjects with and without COPD: the PLATINO study.

Little information exists regarding the epidemiology of the chronic bronchitis phenotype in unselected chronic obstructive pulmonary disease (COPD) populations. We examined the prevalence of the chronic bronchitis phenotype in COPD and non-COPD subjects from the PLATINO study, and investigated how it is associated with important outcomes. Post-bronchodilator forced expiratory volume in 1 s/forced vital capacity <0.70 was used to define COPD. Chronic bronchitis was defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs. We also analysed another definition: cough and phlegm on most days, at least 3 months per year for ≥ 2 yrs. Spirometry was performed in 5,314 subjects (759 with and 4,554 without COPD). The proportion of subjects with and without COPD with chronic bronchitis defined as phlegm on most days, at least 3 months per year for ≥ 2 yrs was 14.4 and 6.2%, respectively. Using the other definition the prevalence was lower: 7.4% with and 2.5% without COPD. Among subjects with COPD, those with chronic bronchitis had worse lung function and general health status, and had more respiratory symptoms, physical activity limitation and exacerbations. Our study helps to understand the prevalence of the chronic bronchitis phenotype in an unselected COPD population at a particular time-point and suggests that chronic bronchitis in COPD is possibly associated with worse outcomes.

Acute bronchodilator responsiveness in subjects with and without airflow obstruction in five Latin American cities: the PLATINO study.

BACKGROUND: Acute bronchodilator responsiveness is an area of discussion in COPD. No information exists regarding this aspect of the disease from an unselected COPD population. We assessed acute bronchodilator responsiveness and factors influencing it in subjects with and without airway obstruction in an epidemiologic sample. METHODS: COPD was defined by GOLD criteria (post-bronchodilator FEV(1)/FVC<0.70). In this analysis, subjects with pre-bronchodilator FEV(1)/FVC <0.70 but > or =0.70 post-bronchodilator were considered to have reversible obstruction. Bronchodilator responsiveness after albuterol 200microg was assessed using three definitions: a) FVC and/or FEV(1) increment > or =12% plus > or =200mL over baseline; b) FEV(1)> or =15% increase over baseline; and c) FEV(1) increase > or =10% of predicted value. RESULTS: There were 756 healthy respiratory subjects, 481 subjects with reversible obstruction and 759 COPD subjects. Depending on the criterion used the proportion of person with acute bronchodilator responsiveness ranged between 15.0-28.2% in COPD, 11.4-21.6% in reversible obstructed and 2.7-7.2% in respiratory healthy. FEV(1) changes were lower (110.6+/-7.40 vs. 164.7+/-11.8mL) and FVC higher (146.5+/-14.2mL vs. -131.0+/-19.6mL) in COPD subjects compared with reversible obstructed. Substantial overlap in FEV(1) and FVC changes was observed among the groups. Acute bronchodilator responsiveness in COPD persons was associated with less obstruction and never smoking. CONCLUSIONS: Over two-thirds of persons with COPD did not demonstrate acute bronchodilator responsiveness. The overall response was small and less than that considered as significant by ATS criteria. The overlap in FEV(1) and FVC changes after bronchodilator among the groups makes it difficult to determine a threshold for separating them.

Frequency of self-reported COPD exacerbation and airflow obstruction in five Latin American cities: the Proyecto Latinoamericano de Investigacion en Obstruccion Pulmonar (PLATINO) study.

BACKGROUND: Recurrent exacerbations are common in COPD patients. Limited information exists regarding exacerbation frequency in COPD patients from epidemiologic studies. We examined the frequency of self-reported exacerbations and the factors influencing exacerbation frequency among COPD patients in a population-based study conducted in Latin America. METHODS: We used a post-bronchodilator FEV(1)/FVC ratio of < 0.70 to define COPD. Exacerbation was self-reported and defined by symptoms (deterioration of breathing symptoms that affected usual daily activities or caused missed work). RESULTS: Spirometry was performed in 5,314 subjects. There were 759 subjects with airflow limitation; of these, 18.2% reported ever having had an exacerbation, 7.9% reported having an exacerbation, and 6.2% reported having an exacerbation requiring at least a doctor visit within the past year. The proportion of individuals with an exacerbation significantly increased by Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages, from 4.2% in stage 1 to 28.9% in stages 3 and 4. The self-reported exacerbation rate was 0.58 exacerbations per year. The rate of exacerbations requiring at least a doctor visit and length of stay in hospital due to exacerbations also increased as COPD severity progressed. The factors associated with having an exacerbation in the past year were dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and disease severity of GOLD stages 3 and 4. CONCLUSIONS: The proportion of individuals with airflow limitation and self-reported exacerbation increases as the disease severity progresses. Dyspnea, prior asthma diagnosis, receiving any respiratory therapy, and more severe obstruction were significantly associated with having an exacerbation in the past year.

Health status perception and airflow obstruction in five Latin American cities: the PLATINO study.

BACKGROUND: COPD is a highly prevalent disease but underdiagnosed, undertreated and possibly under-recognized by patients. Limited information exists regarding patients' perception of COPD severity. We compared patients' general health status perception, degree of breathlessness and physical activity limitation with the severity of their respiratory condition measured by airway obstruction, in a population-based sample. METHODS: We used postbronchodilator FEV(1)/FVC<0.70 to define COPD. Patients' perception of their general health status was derived from the question "in general you would say that your health is: excellent, very good, good, fair or poor?" RESULTS: Spirometry was performed in 5314 subjects: an FEV(1)/FVC ratio below 0.70 was found in 759 subjects. In persons with COPD, general health status decreased with increasing GOLD stages. Over one-half of subjects with stage 2 and one third of those with stages 3 and 4 reported their health status as good to excellent. There was also a disparity between airway obstruction severity and breathlessness intensity. Although the more severe COPD stages were frequently associated with significant compromise of work and everyday activities, patients often tended to provide an optimistic self evaluation of their health status. CONCLUSIONS: The discrepancy observed between general health status, dyspnea severity, physical activity limitation and airway obstruction most likely reflect patients' underperception of disease severity, emphasizing the need for improving case-finding measures and multi-component evaluation of COPD subjects.

Prevalence of sleep related symptoms in four Latin American cities.

STUDY OBJECTIVES: to estimate the prevalence of the most common sleep related symptoms (SRS) in the metropolitan areas of Mexico City, Montevideo (Uruguay), Santiago (Chile), and Caracas (Venezuela). METHODS: The study consisted of a multistage cluster sampling of adults aged > or = 40 years living in metropolitan areas. All participants completed a questionnaire on sleep related symptoms. Simplified respiratory polygraphy during sleep was conducted on 188 subjects from Mexico City. Obstructive sleep apnea syndrome was defined as Epworth Sleepiness Scale score > or = 11 and respiratory disturbance index (RDI) > or = 15 events/h; a cut-off of 15 was chosen because of its high sensitivity and specificity in association with the portable monitor used in the study. RESULTS: The study included 4,533 subjects (1,062 in Mexico City, 941 in Montevideo, 1,173 in Santiago, and 1,357 in Caracas). Snoring was reported by 60.2% (95% CI 58.8% to 61.6%), excessive daytime sleepiness by 16.4% (15.3% to 17.5%), observed apneas by 12.3% (11.4% to 13.3%), insomnia by 34.7% (33.3% to 36%), sedative use by 15.1% (14.1% to 16.2%), daytime napping by 29.2% (27.7% to 30.6%), and a combination of snoring, sleepiness, and observed apneas by 3.4% (2.9% to 4%). Men had a higher frequency of snoring and daytime napping, whereas women reported more insomnia and sedative use. Prevalence of OSAS varied from 2.9% among subjects who denied snoring, excessive daytime sleepiness, and observed apneas, to 23.5% among those reporting these 3 symptoms. CONCLUSIONS: A high prevalence of sleep related symptoms and undiagnosed obstructive sleep apnea in Latin America was observed.

Use of respiratory medication in five Latin American cities: The PLATINO study.

BACKGROUND: There is scanty information regarding respiratory medication prescription pattern in Latin America. We examined the use of bronchodilators and corticosteroids in a population-based study conducted in five Latin American cities. METHODS: Medication use was derived from questions regarding the use of medication "to help breathing" within the previous 12 months, type of medicine, and frequency of use. To minimize the possibility of overdiagnosis, we used postbronchodilator FEV(1)/FVC<0.70 plus FEV(1)<80% as the definition of obstruction. RESULTS: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 360 (6.5%) treated subjects and 5211 not treated. Treated subjects were more likely to be older, women, unemployed, have higher tobacco consumption, higher body mass index, higher FEV(1) reversibility and airway obstruction. They were also more likely to report prior spirometry, prior diagnosis of COPD, asthma or tuberculosis, and more respiratory symptoms. Over half of treated subjects had neither obstruction nor FEV(1) reversibility, and approximately 30% reported no prior diagnosis of asthma or COPD. Prior respiratory diagnoses and wheezing were more strongly associated with treatment than objective measures of airway obstruction. CONCLUSIONS: The use of bronchodilators and/or corticosteroids is common in the general population aged 40 years or older, with over one-half of treated subjects using them without being obstructed.

Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study.

BACKGROUND: The body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD. METHODS: COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC) <0.70. BMI was categorized as underweight (< 20 kg/m(2)), normal weight (20-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), and obese (> or = 30.0 kg/m(2)). RESULTS: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in males with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III-IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. In females with COPD, current smoking, lower education, and GOLD stages II-IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI. CONCLUSIONS: BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD.

[Spirometry reference values after inhalation of 200 microg of salbutamol]. / Valores de referencia para la espirometría después de la inhalación de 200 microg de salbutamol.

OBJECTIVE: The criteria for disease severity established by the Global Initiative for Chronic Obstructive Lung Disease are based on forced expiratory volume in 1 second (FEV1) expressed as a percentage of the predicted value after application of a bronchodilator. This study aims to determine postbronchodilator spirometry reference values. SUBJECTS AND METHODS: A cluster sample of subjects aged 40 years or over was chosen to be representative of the metropolitan areas of 5 Latin American cities (São Paulo, Mexico City, Montevideo, Santiago, and Caracas). Spirometry was performed on 5183 subjects following the recommendations of the American Thoracic Society before and after inhalation of 200 microg of salbutamol. Multiple linear regression equations were fitted for the postbronchodilator spirometric values-FEV1, forced expiratory volume in 6 seconds (FEV6), peak expiratory flow rate, forced vital capacity (FVC), FEV1/FEV6, FEV1/FVC and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). These were adjusted for sex, age, and height in 887 asymptomatic subjects with no history of lung disease. RESULTS: The postbronchodilator reference values for FEV1, FEV1/FVC, and FEV1/FEV6 were on average 3% higher than those obtained before bronchodilation. This apparently small difference caused an upward shift in the 5th percentile (lower limit of normal) of the predicted values. When prebronchodilation instead of postbronchodilation reference values were used, 3.2% of the results for airflow obstruction in our population of over-40-year-olds were false negatives. CONCLUSIONS: The reported reference values are more appropriate for postbronchodilator spirometry and make it possible to reduce the number of misclassifications.

Valores de referencia para la espirometría después de la inhalación de 200 mg de salbutamol / Spirometry reference values after inhalation of 200 mg of salbutamol

Objetivo: La clasificación de la gravedad de la enfermedad pulmonar obstructiva crónica (EPOC) se basa, de acuerdo con la iniciativa GOLD, en el volumen espiratorio forzado en el primer segundo (FEV1) después de usar broncodilatador, expresado como porcentaje del esperado. El propósito de este trabajo ha sido determinar los valores de referencia para la espirometría después de la administración de broncodilatador. Sujetos y métodos: Se realizó un muestreo por conglomerados de sujetos de 40 años o más, representativos de las zonas metropolitanas de São Paulo, Ciudad de México, Montevideo, Santiago y Caracas. Se realizó una espirometría a 5.183 sujetos de acuerdo con las recomendaciones de la American Thoracic Society, antes y después de la inhalación de 200 μg de salbutamol. Se efectuaron regresiones lineales múltiples para los valores espirométricos ­FEV1, volumen espiratorio forzado en 6 s (FEV6), índice de flujo espiratorio máximo, capacidad vital forzada (FVC), FEV1/FEV6, FEV1/FVC y flujo mesoespiratorio forzado­ después del uso del broncodilatador, ajustando por sexo, edad y altura, en 887 sujetos sin evidencia de enfermedad pulmonar previa. Resultados: Los valores de referencia tras broncodilatador para FEV1, FEV1/FVC y FEV1/FEV6 fueron en promedio un 3% mayores que los obtenidos con la espirometría realizada antes de la inhalación del broncodilatador. Esta diferencia, que parece pequeña, causa un desplazamiento hacia arriba en el percentil 5 (límite inferior de la normalidad) de los valores esperados. Si se utiliza el valor de referencia prebroncodilatador, en lugar del posbroncodilatador, se genera un 3,2% de falsos negativos para obstrucción al flujo aéreo en el total de la población de 40 o más años de edad. Conclusiones: Los valores de referencia indicados son más apropiados para espirometrías realizadas después de la inhalación del broncodilatador y permiten minimizar los errores de clasificación

Objective: The criteria for disease severity established by the Global Initiative for Chronic Obstructive Lung Disease are based on forced expiratory volume in 1 second (FEV1) expressed as a percentage of the predicted value after application of a bronchodilator. This study aims to determine postbronchodilator spirometry reference values. Subjects and methods: A cluster sample of subjects aged 40 years or over was chosen to be representative of the metropolitan areas of 5 Latin American cities (São Paulo, Mexico City, Montevideo, Santiago, and Caracas). Spirometry was performed on 5183 subjects following the recommendations of the American Thoracic Society before and after inhalation of 200 μg of salbutamol. Multiple linear regression equations were fitted for the postbronchodilator spirometric values­FEV1, forced expiratory volume in 6 seconds (FEV6), peak expiratory flow rate, forced vital capacity (FVC), FEV1/FEV6, FEV1/FVC and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). These were adjusted for sex, age, and height in 887 asymptomatic subjects with no history of lung disease. Results: The postbronchodilator reference values for FEV1, FEV1/FVC, and FEV1/FEV6 were on average 3% higher than those obtained before bronchodilation. This apparently small difference caused an upward shift in the 5th percentile (lower limit of normal) of the predicted values. When prebronchodilation instead of postbronchodilation reference values were used, 3.2% of the results for airflow obstruction in our population of over-40-year-olds were false negatives. Conclusions: The reported reference values are more appropriate for postbronchodilator spirometry and make it possible to reduce the number of misclassifications

Impact of bronchodilator use on the prevalence of COPD in population-based samples.

The aim of this study was to describe the impact of using bronchodilators on the prevalence of Chronic Obstructive Pulmonary Disease in a population-based survey (Platino study). A cluster sampling of subjects 40 years of age or older, representative of the metropolitan areas of 5 Latin American cities (Sao Paulo, Mexico, Montevideo, Santiago and Caracas) was chosen. Spirometry according to ATS standards was done before and after inhalation of 200 micrograms of salbutamol in 5183 subjects. Prevalences of airflow obstruction were estimated using different criteria, in tests done before and after bronchodilator use, and with reference values for pre- or post-bronchodilator use. Bronchodilator testing reduced the overall prevalence of FEV(1)/FVC% < 0.70 from 21.7% to 14% (35%). In the group with FEV(1)/FVC < 0.70 after bronchodilator use, 21% were asymptomatic from the respiratory point of view, and lacked significant adverse exposures. Subjects below the 5th percentile for FEV(1)/FVC and FEV(1)/FEV(6) were fewer than those with FEV(1)/FVC < 0.70, especially among the elderly. More subjects are below the 5th percentile of FEV(1)/FVC and FEV(1)/FEV(6) using reference values for tests after bronchodilator use than using the reference values determined without bronchodilator testing. Testing after bronchodilator use reduces the prevalence of airflow obstruction from 32 to 39% depending on the definition used. In addition, the subjects who were still obstructed after bronchodilator use were the ones who showed more respiratory symptoms and exposure to tobacco and other smokes and dusts, than subjects with reversible obstruction, suggesting an increased specificity for COPD.

Diagnostic labeling of COPD in five Latin American cities.

BACKGROUND: COPD is a major worldwide problem with a rising prevalence. Despite its importance, there is a lack of information regarding underdiagnosis and misdiagnosis of COPD in different countries. As part of the Proyecto Latinoamericano de Investigación en Obstrucción Pulmonar study, we examined the relationship between prior diagnostic label and airway obstruction in the metropolitan areas of five Latin American cities (São Paulo, Santiago, Mexico City, Montevideo, and Caracas). METHODS: A two-stage sampling strategy was used in each of the five areas to obtain probability samples of adults aged >or= 40 years. Participants completed a questionnaire that included questions on prior diagnoses, and prebronchodilator and postbronchodilator spirometry. A study diagnosis of COPD was based on airway obstruction, defined as a postbronchodilator FEV(1)/FVC < 0.70. RESULTS: Valid spirometry and prior diagnosis information was obtained for 5,303 participants; 758 subjects had a study diagnosis of COPD, of which 672 cases (88.7%) had not been previously diagnosed. The prevalence of undiagnosed COPD was 12.7%, ranging from 6.9% in Mexico City to 18.2% in Montevideo. Among 237 subjects with a prior COPD diagnosis, only 86 subjects (36.3%) had postbronchodilator FEV(1)/FVC < 0.7, while 151 subjects (63.7%) had normal spirometric values. In the same group of 237 subjects, only 34% reported ever undergoing spirometry prior to our study. CONCLUSIONS: Inaccurate diagnostic labeling of COPD represents an important health problem in Latin America. One possible explanation is the low rate of spirometry for COPD diagnosis.

The long-term stability of portable spirometers used in a multinational study of the prevalence of chronic obstructive pulmonary disease.

BACKGROUND: We report the performance of an ultrasound-based portable spirometer (EasyOne) used in a population-based survey of the prevalence of chronic obstructive pulmonary disease, conducted in 5 Latin American cities: São Paulo, Brazil; México City, México; Montevideo, Uruguay; Santiago, Chile; and Caracas, Venezuela (the Latin American COPD Prevalence Study [PLATINO]). METHODS: During the survey period (which ranged from 3 months to 6 months in the various locations) we collected daily calibration data from the 70 EasyOne spirometers used in the 5 survey cities. The calibrations were conducted with a 3-L syringe, and the calibration data were stored in the spirometer's database. RESULTS: Ninety-seven percent of the calibration volumes were within +/- 64 mL (2.1%) of the 3-L calibration signal. Excluding data from the first city studied (São Paulo), where one calibration syringe had to be replaced, 98% of the calibration checks were within +/- 50 mL (1.7%). The measured volume was affected only minimally by the syringe's peak flow or emptying time. CONCLUSION: In these 70 EasyOne spirometers neither calibration nor linearity changed during the study. Such calibration stability is a valuable feature in spirometry surveys and in the clinical setting.

[Spirometric reference values in 5 large Latin American cities for subjects aged 40 years or over]. / Valores de referencia espirométrica en 5 grandes ciudades de Latinoamérica para sujetos de 40 o más años de edad.

OBJECTIVE: In clinical practice, spirometry is a extremely useful test that requires strict quality control, an appropriate strategy for interpretation, and reliable reference values. The aim of this study was to report spirometric reference values for 5 cities in Latin America. PATIENTS AND METHODS: From data for 5315 subjects who had undergone spirometry in the PLATINO study in Caracas, Mexico City, Santiago, São Paulo, and Montevideo, we selected information for 906 (17%) individuals aged between 40 years and 90 years to provide reference values. The chosen subjects had never smoked, were asymptomatic, had not been diagnosed with lung disease, and were not obese. Multiple regression models were constructed with the following spirometric parameters: forced expiratory volume in 1 second (FEV1) and in 6 seconds (FEV6), peak expiratory flow, forced vital capacity (FVC), FEV1/FEV6, FEV1/FVC, and forced midexpiratory flow rate. Height, sex, and age were also included in the model. RESULTS: Average values for the subjects studied were similar to those for the white North American population and the Mexican-American population of the third National Health and Nutrition Examination Survey, but exceeded those of the black population of the same survey by 20%. CONCLUSIONS: The proposed reference values are an improvement on those currently available for Latin America because the participants were chosen by population sampling methods and standardized up-to-date methodology was used.

Valores de referencia espirométrica en 5 grandes ciudades de Latinoamérica para sujetos de 40 o más años de edad / Spirometric reference values in 5 large Latin American Cities for subjects aged 40 years or over

Objetivo: La espirometría es una prueba de gran utilidad clínica, que requiere un estricto control de calidad, una estrategia de interpretación y valores de referencia adecuados. El propósito del presente trabajo es comunicar los valores de referencia para la espirometría en 5 ciudades de Latinoamérica. Pacientes y métodos: El estudio PLATINO se llevó a cabo en Caracas, México, Santiago, São Paulo y Montevideo e incluyó a un total de 5.315 sujetos con espirometría realizada. De ellos, se estudió a 906 (17%) que tenían entre 40 y 90 años de edad para crear valores de referencia, porque nunca habían fumado, estaban asintomáticos y no tenían enfermedad pulmonar diagnosticada ni obesidad. Se efectuaron modelos de regresión múltiple con los valores espirométricos --volumen espiratorio forzado en el primer segundo (FEV1) y en 6 s (FEV6), flujo espiratorio máximo, capacidad vital forzada (FVC), FEV1/FEV6, FEV1/FVC y flujo mesoespiratorio forzado--, la talla, el sexo y la edad. Resultados: Los sujetos estudiados presentaron en promedio valores similares a los de la población norteamericana blanca y americana de origen mexicano del estudio NHANES III, pero superiores a los de la población negra en un 20%. Conclusiones: Los valores de referencia propuestos representan una ventaja sobre los disponibles en la actualidad en Latinoamérica, ya que se eligió a los participantes por métodos de muestreo poblacional y el método empleado es estandarizado y actualizado

Objective: In clinical practice, spirometry is a extremely useful test that requires strict quality control, an appropriate strategy for interpretation, and reliable reference values. The aim of this study was to report spirometric reference values for 5 cities in Latin America. Patients and methods: From data for 5315 subjects who had undergone spirometry in the PLATINO study in Caracas, Mexico City, Santiago, São Paulo, and Montevideo, we selected information for 906 (17%) individuals aged between 40 years and 90 years to provide reference values. The chosen subjects had never smoked, were asymptomatic, had not been diagnosed with lung disease, and were not obese. Multiple regression models were constructed with the following spirometric parameters: forced expiratory volume in 1 second (FEV1) and in 6 seconds (FEV6), peak expiratory flow, forced vital capacity (FVC), FEV1/FEV6, FEV1/FVC, and forced midexpiratory flow rate. Height, sex, and age were also included in the model. Results: Average values for the subjects studied were similar to those for the white North American population and the Mexican-American population of the third National Health and Nutrition Examination Survey, but exceeded those of the black population of the same survey by 20%. Conclusions: The proposed reference values are an improvement on those currently available for Latin America because the participants were chosen by population sampling methods and standardized up-to-date methodology was used

Chronic obstructive pulmonary disease in five Latin American cities (the PLATINO study): a prevalence study.

BACKGROUND: Both the prevalence and mortality attributable to chronic obstructive pulmonary disease (COPD) seem to be increasing in low-income and middle-income countries, but few data are available. The aim of the PLATINO study, launched in 2002, was to describe the epidemiology of COPD in five major Latin American cities: São Paulo (Brazil), Santiago (Chile), Mexico City (Mexico), Montevideo (Uruguay), and Caracas (Venezuela). METHODS: A two-stage sampling strategy was used in the five areas to obtain probability samples of adults aged 40 years or older. These individuals were invited to answer a questionnaire and undergo anthropometry, followed by prebronchodilator and postbronchodilator spirometry. We defined COPD as a ratio less than 0.7 of postbronchodilator forced expiratory volume in the first second over forced vital capacity. FINDINGS: Complete information, including spirometry, was obtained from 963 people in São Paulo, 1173 in Santiago, 1000 in Mexico City, 885 in Montevideo, and 1294 in Caracas. Crude rates of COPD ranged from 7.8% (78 of 1000; 95% CI 5.9-9.7) in Mexico City to 19.7% (174 of 885; 17.2-22.2) in Montevideo. After adjustment for key risk factors, the prevalence of COPD in Mexico City remained significantly lower than that in other cities. INTERPRETATION: These results suggest that COPD is a greater health problem in Latin America than previously realised. Altitude may explain part of the difference in prevalence. Given the high rates of tobacco use in the region, increasing public awareness of the burden of COPD is important.