OBJECTIVE: To study the existence of differences among patients with chronic obstructive pulmonary disease (COPD) hospitalized for exacerbation during different seasons of the year. DESIGN: transversal study. SUBJECTS: all patients admitted to the short-stay medical ward for exacerbation of COPD over a period of one year. MEASUREMENTS: demographic variables, disease history, signs and symptoms, baseline walking test, baseline function tests, baseline blood gases, length of stay and death while hospitalized. INTERVENTIONS: patient variables were described and the characteristics of autumn/winter admissions were compared to those of spring/summer admissions. RESULTS: Two hundred thirty-two patients with a mean age of 70.9 +/- 9.4 years (87.9% male). Eighty-four (36.2%) were admitted in winter, 65 (28%) in spring, 30 (12.9%) in summer and 53 (22.8%) in autumn. Twenty-one percent were being treated with corticoids, 27% were using domiciliary oxygen therapy and 36% had cor pulmonale. Baseline lung function test results were as follows: FEV1 44%, FEV1/FVC 48%, pO2 65.9 mmHg and pCO2 43.5 mmHg. Mean length of stay was 4.9 +/- 6 days; 9 patients (3.9%) died. Only PCO2 upon admission showed seasonal autumn-winter versus spring-summer differences (44.3 versus 49.5, p = 0.0008). Statistically significant differences were not observed for other variables. CONCLUSIONS: Clear seasonal variation can be observed in the number of patients requiring admission due to COPD exacerbation, but we found no relevant seasonally-related differences in disease characteristics.
OBJECTIVE: To study the existence of differences among patients with chronic obstructive pulmonary disease (COPD) hospitalized for exacerbation during different seasons of the year. DESIGN: transversal study. SUBJECTS: all patients admitted to the short-stay medical ward for exacerbation of COPD over a period of one year. MEASUREMENTS: demographic variables, disease history, signs and symptoms, baseline walking test, baseline function tests, baseline blood gases, length of stay and death while hospitalized. INTERVENTIONS:patient variables were described and the characteristics of autumn/winter admissions were compared to those of spring/summer admissions. RESULTS: Two hundred thirty-two patients with a mean age of 70.9 +/- 9.4 years (87.9% male). Eighty-four (36.2%) were admitted in winter, 65 (28%) in spring, 30 (12.9%) in summer and 53 (22.8%) in autumn. Twenty-one percent were being treated with corticoids, 27% were using domiciliary oxygen therapy and 36% had cor pulmonale. Baseline lung function test results were as follows: FEV1 44%, FEV1/FVC 48%, pO2 65.9 mmHg and pCO2 43.5 mmHg. Mean length of stay was 4.9 +/- 6 days; 9 patients (3.9%) died. Only PCO2 upon admission showed seasonal autumn-winter versus spring-summer differences (44.3 versus 49.5, p = 0.0008). Statistically significant differences were not observed for other variables. CONCLUSIONS: Clear seasonal variation can be observed in the number of patients requiring admission due to COPD exacerbation, but we found no relevant seasonally-related differences in disease characteristics.