Objective: To determine whether climate variability influences the number of hospitalizations for respiratory diseases in infants, children, and adults in the city of Campo Grande, Brazil. Methods: We used daily data on admissions for respiratory diseases, precipitation, air temperature, humidity, and wind speed for the 2004-2008 period. We calculated the thermal comfort index, effective temperature, and effective temperature with wind speed (wind-chill or heat index) using the meteorological data obtained. Generalized linear models, with Poisson multiple regression, were used in order to predict hospitalizations for respiratory disease. Results: The variables studied were (collectively) found to show relatively high correlation coefficients in relation to hospital admission for pneumonia in children (R2 = 68.4%), infants (R2 = 71.8%), and adults (R2 = 81.8%). Conclusions: Our results indicate a quantitative risk for an increase in the number of hospitalizations of children, infants, and adults, according to the increase or decrease in temperature, humidity, precipitation, wind speed, and thermal comfort index in the city under study.

Keywords: Meteorology; Pneumonia/epidemiology; Risk factors.

Objective: To evaluate the effect that seasonality has on the occurrence of respiratory symptoms in a Brazilian city with a tropical climate. Methods: This was a cross-sectional study, in which data related to subjects who sought outpatient treatment at a primary health care clinic in the city of Goiânia, Brazil, were correlated with daily meteorological data. Over a one-year period, all the patients who met the inclusion criteria were interviewed on 44 distinct, randomly selected days (11 days per season). We used ANOVA in order to compare the means of the dependent variables by season. Correlations were drawn between each dependent variable and each meteorological variable. The effects of the meteorological variables were analyzed with an AutoRegressive Moving Average with eXogenous input (ARMAX) model. Results: Of the 3,354 participants, 494 (14.6%) had respiratory symptoms. Although temperature variation alone had no effect on the number of individuals with respiratory symptoms, the low levels of humidity during winter resulted in a statistically significant difference among the seasons (p < 0.01). The mean minimum relative humidity on the three days prior to the interviews correlated negatively with the number of subjects with respiratory symptoms (p = 0.04). An ARMAX model including the same variable showed a statistically significant coefficient (p < 0.0001). Conclusions: In this sample, the number of subjects with respiratory symptoms increased significantly when the relative humidity dropped, and this increase could be predicted using meteorological data.

Keywords: Seasons; Tropical climate/adverse effects; Signs and symptoms, respiratory; Logistic models.

Objetivo: Avaliar as alterações da mecânica respiratória e do volume corrente (VC) em lactentes sibilantes em ventilação espontânea após a realização da técnica de expiração lenta e prolongada (ELPr). Métodos: Foram incluídos no estudo lactentes com história de sibilância recorrente e sem exacerbações nos 15 dias anteriores. Para a avaliação da função pulmonar, os lactentes foram sedados e posicionados em decúbito dorsal com máscara facial acoplada a um pneumotacógrafo. As variáveis da respiração corrente - VC e FR - e da mecânica respiratória - complacência do sistema respiratório (Csr), resistência (Rsr) e constante de tempo (psr) - foram mensuradas antes e após a realização de três sequências consecutivas de ELPr. Resultados: Foram avaliados 18 lactentes, com média de idade de 32 ± 11 semanas. Houve um aumento significante no VC após ELPr (79,3 ± 15,6 mL vs. 85,7 ± 17,2 mL; p = 0,009), assim como uma redução na FR (40,6 ± 6,9 ciclos/min vs. 38,8 ± 0,9 ciclos/min; p = 0,042). Entretanto, não houve alterações significantes nos valores da mecânica respiratória (Csr: 11,0 ± 3,1 mL/cmH2O vs. 11,3 ± 2,7 mL/cmH2O; Rsr: 29,9 ± 6,2 cmH2O  mL−1  s−1 vs. 30,8 ± 7,1 cmH2O  mL−1  s−1; e psr: 0,32 ± 0,11 s vs. 0,34 ± 0,12 s; p > 0,05 para todos). Conclusões: Essa técnica de fisioterapia respiratória é capaz de induzir alterações significativas no VC e na FR de lactentes com sibilância recorrente, mesmo na ausência de exacerbações. A manutenção das variáveis da mecânica respiratória indica que a técnica é segura para ser aplicada nesse grupo de pacientes. Estudos com lactentes sintomáticos são necessários para quantificar os efeitos funcionais da técnica.

Keywords: Modalidades de Fisioterapia; Mecânica Respiratória; Lactente; Testes de Função Respiratória.

Objective: To determine the morbidity and mortality related to respiratory diseases among adults attending a tertiary-care hospital in Nigeria. Methods: We carried out a retrospective study of 183 adult patients (> 15 years of age), diagnosed with respiratory diseases between November of 2006 and October of 2008 at the Federal Medical Centre in Ido-Ekiti, Nigeria. Results: Of the 183 patients enrolled in the study, 78 (42.6%) were male and 105 (57.4%) were female, the male:female ratio being 1:1.4. Respiratory diseases were predominant in the 25-44 year age bracket (37.2%) and lower socioeconomic class (81.4%). Pulmonary TB was the leading cause of morbidity (in 42.1%), followed by asthma (in 17.5%) and pneumonia (in 15.3%). Lung cancer was uncommon (in only 0.6%). Pulmonary TB was the leading cause of hospitalization for respiratory disease (in 32%). Pulmonary TB, asthma, pneumonia and pleural pathologies were more common in women, whereas COPD was more common in men. The most common comorbidity was HIV infection (in 11.5%). The overall mean length of hospital stay was 14 days. Overall mortality was 8.7%; 50% of the deaths were attributed to pulmonary TB, 25% were attributed to pleural disease, 12.5% were attributed to pneumonia, and 6.25% were attributed to acute exacerbation of COPD. Mortality was higher in women and in the 25-44 year age bracket. Conclusions: Pulmonary TB, asthma and pneumonia were the leading causes of respiratory disease-related morbidity. Pulmonary TB was the leading cause of respiratory disease-related mortality among the adult Nigerians evaluated. Therefore, these conditions should be given higher priority in patient care. In addition, antiretroviral therapy should be readily accessible and affordable to HIV-infected individuals.

Keywords: Morbidity; Mortality; Respiratory tract diseases; Africa.

Objective: To evaluate sleep-onset time variability, as well as sleep characteristics on weekday and weekend nights, in individuals with moderate-to-severe COPD. Methods: Sleep was objectively assessed by an activity/sleep monitor for seven consecutive nights in individuals with COPD. For analysis, individuals were divided into two groups according to sleep-onset time variability results, characterized by intrasubject standard deviation of sleep-onset time (SOTV) = 60 min or < 60 min. Results: The sample comprised 55 individuals (28 males; mean age = 66 ± 8 years; and median FEV1 % of predicted = 55 [38-62]). When compared with the SOTV<60min group (n = 24), the SOTV=60min group (n = 31) presented shorter total sleep time (5.1 ± 1.3 h vs. 6.0 ± 1.3 h; p = 0.006), lower sleep efficiency (73 ± 12% vs. 65 ± 13%; p = 0.030), longer wake time after sleep onset (155 ± 66 min vs. 115 ± 52 min; p = 0.023), longer duration of wake bouts (19 [16-28] min vs. 16 [13-22] min; p = 0.025), and higher number of steps at night (143 [104-213] vs. 80 [59-135]; p = 0.002). In general, sleep characteristics were poor regardless of the day of the week, the only significant difference being that the participants woke up about 30 min later on weekends than on weekdays (p = 0.013). Conclusions: Sleep-onset time varied over 1 h in a standard week in the majority of individuals with COPD in this sample, and a more irregular sleep onset indicated poor sleep quality both on weekdays and weekends. Sleep hygiene guidance could benefit these individuals if it is integrated with their health care.

Keywords: Pulmonary disease, chronic obstructive; Sleep; Actigraphy.

Objective: To study variations in climate (dry or rainy periods) and health services use for the treatment of asthma in children under five years of age. Methods: An ecological study was conducted and involved analysis of the medical charts of all children under the age of five that were diagnosed with asthma and treated in the Municipal Emergency Room of the city of Cuiabá, located in the state of Mato Grosso, Brazil. In accordance with the geographic location of Cuiabá, two climatic periods were identified: a dry season (from May to October) and a rainy season (from November to April). Results: The percentage of children treated that were diagnosed with asthma was 12.2% (3140/25,802), with no gender-based difference. Children from 3 to 5 years of age were most often affected. The overall asthma hospitalization rate was 1.3% (336/25,802), rising to 10.7% (336/3140) among the asthmatic children treated in the emergency room. In the rainy season, the percentage of outpatients seeking treatment for asthma was higher than in the dry season: 39.1% (1228/3140) versus 60.9% (1912/3140). However, during the dry season, a greater proportion of such patients were hospitalized: 52.3% (176/336) versus 47.7% (160/336). These differences were statistically significant (p < 0.05). Conclusions: The dry season, which was correlated with higher asthma hospitalization rates, seems to be related to more severe cases of asthma in children under five years of age.

Keywords: Asthma/prevention & control; Allergens/adverse effects; Respiratory hypersensitivity; Environmental monitoring;

Objective: To compare the expiratory flow increase technique (EFIT) and vibration accompanied by postural drainage (PD) in terms of their effects on the heart rate (HR), respiratory rate (RR) and SpO2 of infants with acute viral bronchiolitis (AVB). Methods: Infants with clinical and radiological diagnosis of AVB were analyzed. The HR, RR and SpO2 were registered at four time points: prior to the procedure; and at 10, 30 and 60 min after the procedure. The patients were divided into three groups: submitted to the EFIT; submitted to vibration/PD; and control. Results: We included 81 infants, 27 per group, with a mean age of 4.52 years and a mean weight of 6.56 kg. Using ANOVA, we found that the EFIT and vibration/PD groups presented no significant differences in relation to the control group in terms of the mean values for HR, RR or SpO2 (p > 0.05). Considering only the four time points evaluated, the mean RR was significantly lower in the EFIT and vibration/PD groups than in the control group (p < 0.05). Conclusions: In terms of overall improvement of cardiorespiratory parameters, neither the EFIT nor vibration/PD provided any benefit to infants with BVA. However, over time, respiratory physical therapy seems to contribute to decreasing the RR in these patients.

Keywords: Bronchiolitis, viral; Physical therapy modalities; Infant.

Objective: To determine whether a restrictive pattern on spirometry is associated with the level of physical activity in daily life (PADL), as well as with cardiovascular disease (CVD) risk factors, in asymptomatic adults. Methods: A total of 374 participants (mean age, 41 ± 14 years) underwent spirometry, which included the determination of FVC and FEV1. A restrictive pattern on spirometry was defined as an FEV1/FVC ratio > 0.7 and an FVC < 80% of the predicted value. After conducting demographic, anthropometric, and CVD risk assessments, we evaluated body composition, muscle function, and postural balance, as well as performing cardiopulmonary exercise testing and administering the six-minute walk test. The PADL was quantified with a triaxial accelerometer. Results: A restrictive pattern on spirometry was found in 10% of the subjects. After multivariate logistic regression, adjusted for confounders (PADL and cardiorespiratory fitness), the following variables retained significance (OR; 95% CI) as predictors of a restrictive pattern: systemic arterial hypertension (17.5; 1.65-184.8), smoking (11.6; 1.56-87.5), physical inactivity (8.1; 1.43-46.4), larger center-of-pressure area while standing on a force platform (1.34; 1.05-1.71); and dyslipidemia (1.89; 1.12-1.98). Conclusions: A restrictive pattern on spirometry appears to be common in asymptomatic adults. We found that CVD risk factors, especially systemic arterial hypertension, smoking, and physical inactivity, were directly associated with a restrictive pattern, even when the analysis was adjusted for PADL and cardiorespiratory fitness. Longitudinal studies are needed in order to improve understanding of the etiology of a restrictive pattern as well as to aid in the design of preventive strategies.

Keywords: Spirometry; Hypertension; Motor activity; Sedentary lifestyle; Smoking.

Objective: To investigate the correlation between respiratory syncytial viral load and length of hospitalization in infants with acute wheezing episodes. Methods: This was a two-year, cross-sectional study of infants ≤ 12 months of age with bronchiolitis at the time of admission to a tertiary hospital. For the identification of respiratory viruses, nasopharyngeal secretions were collected. Samples were analyzed (throughout the study period) by direct immunofluorescence and (in the second year of the study) by quantitative real-time PCR. We screened for three human viruses: rhinovirus, respiratory syncytial virus, and metapneumovirus. Results: Of 110 samples evaluated by direct immunofluorescence, 56 (50.9%) were positive for a single virus, and 16 (14.5%) were positive for two or more viruses. Among those 72 samples, the most prevalent virus was respiratory syncytial virus, followed by influenza. Of 56 samples evaluated by quantitative real-time PCR, 24 (42.8%) were positive for a single virus, and 1 (1.7%) was positive for two viruses. Among those 25 samples, the most prevalent virus was again respiratory syncytial virus, followed by human rhinovirus. Coinfection did not influence the length of the hospital stay or other outcome s. In addition, there was no association between respiratory syncytial virus load and the length of hospitalization. Conclusions: Neither coinfection nor respiratory syncytial viral load appears to influence the outcomes of acute bronchiolitis in infants.

Keywords: Bronchiolitis; Coinfection; Viral load; Hospitalization; Respiratory syncytial virus, human.

Objective: To evaluate submaximal exercise tolerance and respiratory muscle strength in relation to forward head posture (FHP) and respiratory mode in children, comparing mouth-breathing (MB) children with nasal-breathing (NB) children. Methods: This was a controlled, analytical cross-sectional study involving children in the 8-12 year age bracket with a clinical otorhinolaryngology diagnosis of MB, recruited between October of 2010 and January of 2011 from the Mouth Breather Clinic at the State University of Campinas Hospital de Clínicas, located in the city of Campinas, Brazil. The exclusion criteria were obesity, asthma, chronic respiratory diseases, heart disease, and neurological or orthopedic disorders. All of the participants underwent postural assessment and the six-minute walk test (6MWT), together with determination of MIP and MEP. Results: Of the 92 children in the study, 30 presented with MB and 62 presented with NB. In the MB group, the differences between those with moderate or severe FHP and those with normal head posture, in terms of the mean MIP, MEP and six-minute walk distance (6MWD), were not significant (p = 0.079, p = 0.622, and p = 0.957, respectively). In the NB group, the mean values of MIP and MEP were higher in the children with moderate FHP than in those with normal head posture (p = 0.003 and p = 0.004, respectively). The mean MIP, MEP, and 6MWD were lower in the MB group than in the NB group. Values of MIP and MEP were highest in the children with moderate FHP. Conclusions: Respiratory biomechanics and exercise capacity were negatively affected by MB. The presence of moderate FHP acted as a compensatory mechanism in order to improve respiratory muscle function.

Keywords: Mouth breathing; Posture; Exercise tolerance; Respiratory mechanics.

Objective: To study the prevalence of respiratory morbidity among passive smoking children and to determine the effects of environmental tobacco smoke in the upper and lower respiratory system of these children in the city of Fortaleza, Ceará, Brazil. Cases and method: This is a cross sectional study of 1,104 children under the 5 years old. Information about respiratory symptoms and illnesses of the children, family history of respiratory diseases, smoking habits of household members and housing conditions were assessed by a questionnaire addressed to the children's parents. Results: Among the 1,104 children, 558 were males and 546 were females. Respiratory morbidity was greater in the children exposed to environmental tobacco smoke than in those who were not exposed (82% vs 74%). Regarding the lower respiratory tract, the most frequent complaints were wheeze (57.7%; OR = 1.32; IC 95%: 1.04-1.68), dyspnea (43.8%; OR = 1.56; IC 95%: 1.22-1.99), asthma, bronchitis or pneumonia (29.4%; OR = 1.31; IC 95%: 1.00-1.71). As to the upper respiratory tract, rhinitis was the most frequent complaint (38.1%; OR = 1.46; IC 95%: 1.13-1.88). Logistic regression analysis showed that the lower respiratory tract complaints were associated with: mother's smoking (OR = 2.02; IC 95% 1.12-3.66); father's smoking (OR = 1.99; IC 95%: 1.16-3.40); mould (OR = 1.55; IC 95%: 1.14-2.13) and family history of respiratory diseases (OR = 1.72; IC 95%: 1.26-2.35). Upper respiratory tract complaints were associated with: family history of respiratory diseases (OR = 1.44; IC 95%: 1.13-1.85) and mother's smoking (OR = 1.54; IC 95%: 1.01-2.35). Conclusion: The authors concluded that the exposure to environmental tobacco smoke is a risk factor for upper and lower respiratory morbidity among children under 5 years old.

Objective: To evaluate spirometric patterns of respiratory disorders and their relationship with functional severity and maximal expiratory flows at low lung volumes in patients with cystic fibrosis (CF). Methods: A retrospective cross-sectional study including adolescents and adults with CF. All of the patients were submitted to spirometry. Patients were classified as having preserved respiratory function, obstructive lung disease (OLD), OLD with reduced FVC, presumptive restrictive lung disease (RLD) or mixed obstructive and restrictive lung disease (MORLD). Maximal expiratory flows at low lung volumes were assessed using FEF25-75%, FEF75% and FEF75%/FVC. We included 65 normal subjects, also submitted to spirometry, as a control group. Results: The study group included 65 patients: 8 (12.3%) with preserved lung function; 18 (27.7%) with OLD; 24 (36.9%) with OLD and reduced FVC; 5 (7.7%) with presumptive RLD; and 10 (15.4%) with MORLD. The FEV1 was significantly lower in the OLD with reduced FVC group and the MORLD group than in the other groups (p < 0.001). In the patients with preserved respiratory function, FEF25-75% and FEF75% were significantly reduced in 1 patient, as was FEF75%/FVC in 2 patients. Conclusions: The respiratory pattern was impaired in 88% of the patients with CF. The most common pattern was OLD with reduced FVC. The degree of functional impairment was greater in the OLD with reduced FVC group and in the MORLD group than in the other groups. Maximal expiratory flows at low lung volumes were impaired in a low percentage of patients with preserved respiratory function.

Keywords: Cystic fibrosis; Respiratory function tests; Spirometry; Maximal expiratory flow-volume curves.

Smoking among women has drawn increasing attention because of the increase (or less pronounced decrease) in its prevalence when compared with that observed for men, as well as because of the specific effects that smoking has on women's health. For the 2010 "World No Tobacco Day", the World Health Organization chose the theme "Gender and tobacco with an emphasis on marketing to women", with the aim of encouraging policies to combat marketing strategies employed by the tobacco industry and to curb the epidemic of smoking among women. In this article, we discuss the characteristics of smoking among women, addressing factors such as smoking prevalence, nicotine dependence, the role of the tobacco industry, health risks, approaches to smoking cessation, treatment strategies, and prevention measures.

Keywords: Smoking; Women's health; Tobacco industry.

Background: Ventilator-associated pneumonia is the most common nosocomial infection occurring in intensive care units. Objective: To determinate the impact of multidrug-resistant bacteria on morbidity and mortality in patients with ventilator-associated pneumonia. Method: Retrospective cohort study. Over 40 consecutive months, 91 patients on mechanical ventilation developed pneumonia. Cases were grouped into those caused by multidrug-resistant microorganisms and those caused by drug-sensitive microorganisms. Results: Multidrug-resistant bacteria were isolated in 75 cases (82.4%) and drug-sensitive bacteria in 16 (17.6%). Clinical and epidemiological characteristics were not statistically different between the groups. Staphylococcus aureus was responsible for 27.5% of ventilator-associated pneumonia episodes and Pseudomonas aeruginosa for 17.6%. Early-onset ventilator-associated pneumonia occurred in 33 patients (36.3%) and late-onset in 58 (63.7%). Time on mechanical ventilation, length of intensive care unit stay and overall length of hospital stay were not statistically different between groups. Empirical treatment was considered inadequate in 42 patients with pneumonia caused by multidrug-resistant microorganisms (56%) and in 4 with pneumonia caused by drug-sensitive microorganisms (25%) (p = 0.02). Death occurred in 46 patients with pneumonia caused by multidrug-resistant microorganisms (61.3%) and in 4 with pneumonia caused by drug-sensitive microorganisms (25%) (p = 0.008). Conclusion: Bacterial multidrug-resistance had no impact on morbidity but was associated with higher mortality.

Keywords: Pneumonia bacterial/etiology. Respiration artificial/complications. Indicators of morbidity and mortality.

Objective: To investigate dyspnea in individuals with Class II or III obesity and look for correlations among the respiratory data related to such individuals. Methods: This study involved 49 subjects with a body mass index >35 kg/m2, divided into two groups (those with dyspnea and those without). The baseline dyspnea index was evaluated, as were spirometry findings, maximal respiratory pressures and arterial blood gas analysis. Results: Of the 49 subjects evaluated, 37 reported dyspnea and 12 reported no dyspnea. The baseline dyspnea index differed between the two groups. The mean values were within the range of normality for all subjects and all parameters, except for the following: ratio of residual volume to total lung capacity; expiratory reserve volume; and the alveolar-arterial oxygen gradient. The subjects with dyspnea presented significantly lower values for expiratory reserve volume, maximal expiratory pressure and arterial pH. In all subjects, body mass index correlated significantly with the following: baseline dyspnea index; the residual volume/total lung capacity ratio; the forced expiratory volume in one second/forced vital capacity ratio; forced expiratory flow between 25% and 75% of forced vital capacity; arterial oxygen tension; the alveolar-arterial oxygen gradient; and arterial carbon dioxide tension. The baseline dyspnea index was found to correlate significantly with the following parameters: residual volume/total lung capacity ratio; expiratory reserve volume; arterial oxygen tension; the alveolar-arterial oxygen gradient; and arterial carbon dioxide tension. Conclusion:  Dyspnea is a common complaint in individuals with class II or III obesity. Such individuals present a pronounced reduction in expiratory reserve volume and an increase in the alveolar-arterial oxygen gradient. The correlations found suggest that obese individuals present dysfunction of the lower airways, and that obesity itself plays a role in the genesis of dyspnea.

Keywords: Obesity/complications; Dyspnea/epidemiology; Dyspnea/physiopathology; Respiratory function tests

Objective: To determine the intrarater and interrater reliability of cirtometry (measurements of the circumference of the chest and abdomen taken during respiratory movements) as well as its correlation with pulmonary volumes measured by respiratory inductive plethysmography. Methods: A total of 40 healthy individuals were evaluated. The mean age was 28 years. The measurements were taken in the supine position at three different time points: at rest, at maximal inspiration, and at maximal expiration. Two trained investigators, each of whom was blinded as to the results obtained by the other, performed the measurements. The Friedman test was used to determine intrarater reliability, and the Wilcoxon test, together with the intraclass correlation coefficient, were used to determine interrater reliability. The correlation between the cirtometry measurements and the plethysmography results was obtained using Spearman's correlation coefficient. The level of significance was set at 0.05 for all tests. Results: Intrarater reliability was satisfactory. Regarding interrater reliability, statistically significant differences (2.8 cm at the most) were found in all sets of measurements. However, through the analysis of the intraclass correlation coefficient, the investigators were found to be responsible only for a small portion of the variability (1.2-5.08%) found among the measurements. When the cirtometry measurements were compared to the volumes measured by respiratory inductive plethysmography, low correlations (range, r = 0.170-0.343) were found. Conclusions: The findings of this study suggest that, although cirtometry is a reliable measurement, it does not accurately measure pulmonary volumes.

Keywords: Reproducibility of results; Lung volume measurements; Plethysmography; Statistics, nonparametric.

Objective: Few studies have evaluated the variability of the perception of dyspnea in healthy subjects. The objective of this study was to evaluate the variability of the perception of dyspnea in healthy subjects during breathing against increasing inspiratory resistive loads, as well as to assess the association between the level of perception of dyspnea and the level of physical activity. Methods: This was a cross-sectional study involving healthy individuals 16 years of age or older. Subjects underwent inspiratory resistive loading testing, in which the level of perception of dyspnea was quantified with the modified Borg scale. We also determined body mass indices (BMIs), assessed maximal respiratory pressures, performed pulmonary function tests, applied the international physical activity questionnaire (IPAQ)-long form, and conducted six-minute walk tests (6MWTs). The level of perception of dyspnea was classified as low (Borg score < 2), intermediate (Borg score, 2-5), or high (Borg score > 5). Results: We included 48 healthy subjects in the study. Forty-two subjects completed the test up to a load of 46.7 cmH2O/L/s. The level of perception of dyspnea was classified as low, intermediate, and high in 13, 19, and 10 subjects, respectively. The level of perception of dyspnea was not significantly associated with age, gender, BMI, IPAQ-long form score, maximal respiratory pressures, or pulmonary function test results. Conclusions: The scores for perceived dyspnea induced by inspiratory resistive loading in healthy subjects presented wide variability. The perception of dyspnea was classified as low in 31% of the subjects, intermediate in 45%, and high in 24%. There was no association between the level of perception of dyspnea and the level of physical activity (IPAQ or six-minute walk distance).

Keywords: Dyspnea; Respiratory function tests; Exercise test.