Results
Table 1 shows the patient characteristics of the 307 patients with COPD. There were 100 (32.9%) active smokers at recruitment; 303 had a history of smoking, with a mean consumption of 50.5 pack years (SD, 35.9). Also, 262 patients (86.5%) were taking a median dose of 1,000 mg of beclomethasone equivalents (IQR, 500-1,000) of inhaled steroids; 41 patients (13.3%) were not taking inhaled steroids, and the dosage was unknown for four patients Viagra Generic. The patients recorded diary card data for 1,037 patient years and experienced 2,606 exacerbations, a median of 2.13 per patient per year (IQR, 0.94-3.32). Of these, 676 exacerbations were experienced by 212 patients in the warm seasons, and 1,052 exacerbations by 251 patients in the cold seasons: 197 patients experienced exacerbations in both seasons, and outside of the two seasons, 878 exacerbations were experienced.
Table 1—Characteristics of the 307 Patients
Characteristic | Value |
Age y | 68.1 (8.4) |
FEVp L | 1.12 (0.46) |
FEVP % predicted | 44.4 (16.1) |
FVC, L | 2.51 (0.83) |
FEV/FVC | 0.45 (0.12) |
Smoking, pack y | 50.5 (35.9) |
Time in study, median, (IQR), d | 1,021 (631-1,576) |
Exacerbations, median, (IQR), No. | 6(2-12) |
Exacerbations per year | 2.13 (0.94-3.32) |
Male, No. (%) | 196 (63.8) |
Chronic sputum, No. (%) | 158 (51.6) |
Current smoking, No. (%) | 100 (32.9) |
Data are given as mean (SD) unless otherwise indicated. Smoking history missing for four patients at recruitment. IQR = interquartile range
Patients were under observation in summer for a median 352 days (IQR, 224-523) and in winter for a median 338 days (IQR, 222-525).
There were 55.6% more exacerbations in the cold seasons compared with the warm seasons. The average temperature in the warm seasons was 16.7°C (range, 6.4 to 28.2), and in the cold seasons, 6.6°C (range, —3.5 to 15.6).
Exacerbation Recovery and Temperature
The median recovery time from all symptoms in the warm seasons was shorter at 9 days (IQR, 5-16; n = 595) compared with 10 days in the cold seasons (IQR, 6-19; n = 892; P = .005).