Substudy 11 Executive Summary
Substudy 11: An Economic Evaluation of Hospital Based and Home Based Intravenous Antibiotic Therapy for Individuals with Cellulitis
by Peter C. Coyte
Modifications to the site of care for individuals on antibiotic IV therapy may have a significant impact on costs borne by both the public sector and by clients and their families. Moreover, changes to the site of care have the potential to exert a significant impact on the well-being of patients and their caregivers. The potential to change clinical practices, the large number of patients who may be affected, the magnitude of the resource implications, and the potential to influence client and caregiver well-being were the main motivating forces behind this study.
The purpose of this cohort study was to conduct a multi-site prospective economic evaluation of the costs and consequences of home- and hospital-based antibiotic IV therapy for clients with cellulitis. The objective of this study was to identify the incremental costs and consequences to society associated with home-based rather than hospital-based antibiotic IV therapy for the treatment of cellulitis over a one-month time frame.
The results of this observational cohort study showed that few patients with cellulitis requiring IV antibiotics were being treated with either home care or hospitalization. Nearly two-thirds of patients were receiving care with repeated emergency department visits. When emergency department physicians attempted to arrange home care for patients, they were told that in-home nursing was not be available for several days, at which time patients would be expected to be able to switch to oral antibiotic therapy. Rather than hospitalize the patients, the physicians asked them to return to the emergency department every eight hours for IV antibiotic dosing.
Patients treated in the hospital had the highest Charlson Co-morbidity Score and the lowest health-related quality of life score, followed by patients treated with multiple visits to the emergency department and patients with home care. Patients treated with home care healed faster than patients treated with multiple visits to the emergency department or hospitalized patients. Patients treated in the hospital and patients treated with home care had more complications than patients treated with multiple visits to the emergency department. Patients treated in the hospital were also more expensive to treat than patients with treated with multiple visits to the emergency department or patients treated with home care.
Due to the small samples of patients in the home care and hospital setting, the heterogeneity of patients treated with multiple visits to the emergency department and the significant co-morbidity of patients treated in the hospital setting, clinical outcomes, complications, costs and health-related quality of life comparisons in different health care settings were difficult to discern.
This economic evaluation attempted to address the acknowledged and widely-lamented absence of appropriate economic data concerning the costs and consequences of home- and hospital-based antibiotic IV therapy for cellulitis study subjects. In addition, we attempted to determine the potential to target home-based IV therapy to particular study subject sub-groups for which the societal costs of service provision were relatively low and for which the enhanced outcomes were relatively great.
Due to the heterogeneous populations of patients, as well as the limited sample sizes within treatment setting groups, this study did not completely answer the important research question concerning the cost and outcome differences by health care setting. Although some insight into the quality and cost of care was provided for the different treatment settings, further data collection is required for more statistically significant and meaningful comparisons.
This economic evaluation informs and facilitates modifications and improvements in treatments for study subjects receiving antibiotic IV therapy for cellulitis as it yields information on how home care and emergency department services are currently meeting needs in the study hospitals. Capturing 'real-world' effectiveness of treatment information is useful as health system restructuring continues in Canada.
This study was conducted at two Toronto hospitals (Mount Sinai Hospital and Sunnybrook and Women's College Health Sciences Centre). A research coordinator conducted weekly chart reviews to find patients who met the eligibility criteria. Patients who were diagnosed with cellulitis and required IV antibiotics were considered potentially eligible. Enrollment occurred over an 11-month period (February 1st, 2000 to December 31st, 2000) at Mount Sinai and over a two-month period (November 15th, 2000 to January 15th, 2001) at Sunnybrook, and each patient was followed for one-month following the initiation of therapy. Patients identified during the weekly chart review were contacted and asked to participate in the study. Clinical and economic data for consenting patients was collected at baseline, day 15 and day 30 (termination) following the initiation of therapy. The decision to collect data for 30 days was based on the anticipated resolution of the infection within a month of presentation.