Readmission predictors in patients with chronic obstructive pulmonary disease hospitalized for an exacerbation

Introduction: Hospitalizations for chronic obstructive pulmonary disease (COPD) exacerbations increase risk of readmission due to an exacerbation and lead to higher mortality. Aims: To determine factors which may contribute to readmission due to a new episode of COPD exacerbation. Methods: We reviewed medical charts of all patients with a discharge diagnosis of a COPD exacerbation admitted to Fukujuji hospital, the secondary respiratory hospital serving the north-west of Tokyo, from October 2008 to March 2010. Data collected included age, sex, pack-year history of smoking, body mass index (BMI), previous FEV1, arterial blood gases at an emergency room, and incidence of long term oxygen therapy (LTOT). Comorbidities were measured with Charlson Comorbidity Index. Length of stay at this time as well as the number of hospitalizations for a COPD exacerbation in the previous 12 months were obtained. Readmission was defined as one or more hospitalization for an exacerbation within six months after discharge. Results: 66 patients (57 men) were included in this study (mean FEV1 38.4% predicted). 19 of these patients (28.8%) were readmitted. Readmission was significantly associated with receiving LTOT (odds ratio [OR], 3.63 [95%CI, 1.18 to 11.2]; p=0.04), hospitalizations for a COPD exacerbation in the previous 12 months (OR, 20.2 [CI, 4.58 to 88.8]; p<0.001), and Charlson Comorbidity Index (>1 vs 0 or 1) (OR, 7.56 [CI, 2.08 to 27.53]; p=0.003). Conclusions: Receiving LTOT, hospitalizations during the previous year, and comorbidities are strong predictors of readmission due to a new episode of exacerbation in our COPD patients.