Tuesday, December 2, 2014
Asthmatic component to COPD
Of 853 potentially eligible patients, 222 patients (26%) who reported only asthma and 47 patients (6%) for whom a diagnosis was missing were exeluded from current analysis. We also excluded 385 patients (66%) who were not discharged to home (ie, admitted to observation unit, 5 patients [1%]; admitted to a regular ward, 300 patients [51%]; admitted to the ICU, 63 patients [11%]; or transferred to another hospital or received other disposition, 17 patients [3%]). Among the 199 patients with COPD exacerbations who were discharged to home, we enrolled 151 patients (76%).
The enrolled patients did not differ from the nonenrolled patients across multiple sociodemographic factors. A total of 140 patients had complete follow-up data (follow-up rate, 93%). Of the original 29 sites, 28 contributed patients to this analysis (range, 2 to 13 patients per site). These 140 patients, compared to those not contacted by telephone (11 patients), did not differ by age, sex, race, reported diagnosis (ie, mixed asthma-COPD or COPD only), number of COPD exacerbations during the past year, home oxygen use, and COPD medications used before/during/after the ED visit.
Among the 140 patients, 30 patients (21%; 95% CI, 15 to 29) reported COPD exacerbation relapse within 14 days of their original ED visit. Relapse events occurred over the entire follow-up period, with an average daily relapse rate of 1.4%. The cohort consisted of almost the same number of men and women, and 60% of patients were white. Most of the patients had a PCP and some type of medical insurance. None of these demographic factors were different in the relapse and nonrelapse groups . A total of 32% of patients were current smokers, 57% were past smokers, and 11% were never-smokers.
Among the 15 never-smokers, 8 reported symptoms compatible with chronic bronchitis (ie, mucus-producing cough most days of the month, 3 months of the year for two successive years) and/or they received diagnoses of asthma/COPD after age 35 years. When we excluded the seven never-smokers, who did not report chronic bronchitis symptoms and whose age of diagnosis was < 35 years, the results did not vary materially.
Half of the patients reported an asthmatic component to their COPD, but this physician diagnosis was unrelated to relapse risk. On univariate analysis, chronic severity and management of COPD were not different in the relapse and nonrelapse groups, except for the number of urgent clinic or ED visits for COPD exacerbation during the past year, and receiving systemic corticosteroids over the past 4 weeks.