The Impact of Comorbidities on Calgary Hospital Utilization in Patients With Chronic Obstructive Pulmonary Disease and Heart Failure.

Background Chronic obstructive pulmonary disease (COPD) and heart failure (HF) are chronic conditions with high acute care utilization. Disease-specific order sets were developed for patients with COPD or HF in Calgary to reduce total days in hospital for this population of patients. However, many patients have comorbidities which may contribute to hospital utilization; thus, disease-specific order sets may not be an optimal solution to reduce overall acute care utilization. Methods Inpatient data on Calgary hospitalizations for COPD or HF between April 1, 2017 - March 31, 2019 and associated diagnoses were identified. Outcomes included total days in hospital and length of stay for COPD and HF patients stratified by number of comorbidities. Results Total days in hospital increased with the number of comorbidities for both conditions. During the study period, 131 patients with COPD and no comorbidities had a median length of stay of three days (IQR: 3) compared to 3,911 COPD patients with one to five comorbidities with a median length of stay of seven days (IQR: 9). There were 47 patients with HF and no comorbidities with a median length of stay of four days (IQR: 5) compared to 6,273 HF patients with one to five comorbidities with a median length of stay of nine days (IQR: 12). Common comorbidities included hypertension, type 2 diabetes, and acute renal failure. COPD and HF are frequently comorbid.  Conclusions Total days in hospital for patients with COPD or HF is positively correlated with the number of comorbidities. COPD or HF patients with between one to five comorbidities (compared to those with no comorbidities, and those with more than five comorbidities) represent the majority of total days in hospital, and the majority of patients. This highlights the importance of focusing on patients with comorbidities in efforts to reduce hospital utilization, and suggests that concurrent management of commonly occurring comorbidities for HF and COPD patients may be necessary to achieve this goal.