Factors predicting a hospital stay of over 3 days in patients with acute exacerbation of chronic obstructive pulmonary disease

Objective. To investigate the factors predicting a hospital stay of over 3 days in patients who required hospitalization for acute exacerbation of chronic obstructive pulmonary disease (COPD). Design and setting. A cross-sectional tudy was done at a tertiary hospital serving an area of 500 000 inhabitants. Subjects. A total of 273 patients (alpha=0.05; accuracy=5.94%) who had been admitted consecutively to the Short Stay Medical Unit at the Juan Canalejo Hospital in A Coruna, from February 1998 to March 1999, with a diagnosis focusing on exacerbation of COPD. Methods. Demographic variables, past medical history, symptoms, arterial blood gases, functional tests, treatment and the cause of exacerbation were studied in each patient. The hospital stay was dichotomized into less than or equal to3 vs. >3 days. The prognostic factors of a hospital stay were determined by log regression. Results. The mean stay was 4.6 +/- 5.1 days (range: 1-64). After monitoring the associated covariables, the following were found to have an independent effect on the prediction of a hospital stay of over 3 days: weekend admissions (OR=4.17; 95% CI: 2.42-7.18), the presence of cor pulmonale (OR=2.19; 95% CI: 1.27-3.78), and the respiratory rate on admission (OR=1.09; 95% CI: 1.03-1.14). Arterial blood gases and functional tests showed no independent effect. Conclusions. The factors having an independent prognostic value in determining the length of hospital stays in patients with COPD are weekend admission, cor pulmonale and respiratory rate. Additional studies are required to validate these findings.