Topic Abstract
Background
Peripheral arterial disease (PAD) is characterized by atherosclerotic stenosis and occlusions in the peripheral arteries and affects up to 30% of the US adult population. Peripheral vascular interventions (PVI) of the lower extremities have increased exponentially in the past decade. However, for many patients, the optimal approach, medical therapy or revascularization, surgery versus endovascular therapy, remains unclear.
Objective/Research Question
The objective of this study is to better inform current practice regarding treatment of PAD in community-based settings and to address limitations of prior PVI studies. A retrospective clinical registry of patients with peripheral arterial disease (PAD) will assess the comparative effectiveness of surgical versus endovascular therapy for PAD. A prospective cohort study will assess changes in health status of PAD patients treated medically, surgery or endovascular therapy.
Study Design
The project is comprised of two main studies. A retrospective cohort of patients undergoing surgical or endovascular therapy for lower extremity PAD will be assembled from 2 large integrated healthcare delivery systems. A prospective cohort of PAD patients treated with medical therapy, surgery or endovascular therapy will be assembled from two healthcare organizations in Colorado to assess changes in health status at baseline and 6-months following treatment.
Methods
The retrospective registry will include patients undergoing lower extremity revascularization between 1/1/2005 and 12/31/2010 at two healthcare organizations. Data will be collected from each healthcare organization’s member databases and includes patient co-morbidities, outpatient visits, morbidity, and mortality. Detailed chart review will be conducted on a random sample of patients (n=3500) from the registry togather additional details related to the procedures. For all revascularization patients, we will describe baseline patient demographics, co-morbidities, longitudinal medication use (e.g., statins, cilostazol), morbidity (major and minor lower extremity amputation, stroke, and myocardial infarction [MI]) and mortality according to revascularization treatment. Comparative effectiveness analyses comparing surgical versus endovascular approaches will focus on the chart review sample where critical factors such as procedure indication, lesion location, and procedure details will be available. Time to development of repeat revascularization or the combined morbidity/mortality outcomes will be modeled using survival analysis methods. Adjusting for confounding will include stratification by key variables (i.e. procedure indication) as well as propensity scores used as inverse probability weights in the time to event models
In the prospective study, 450 PAD patients from two healthcare organizations in Colorado will be recruited and complete quality of life and functional status questionnaires at baseline and six months (PAQ, WIC, EQ-5, and Residential Status and Ambulatory Function). The primary outcome will be change in health status scores (six months minus baseline) for the treatment groups of interest (endovascular revascularization, surgical revascularization, or medical therapy). Score changes over time will be modeled using generalized linear mixed models.
Expected Outputs
Five scientific reports addressing each main objective will be submitted at the conclusion of the study.