This study will analyze treatment selection and outcomes for approximately 1300 consecutive patients who make an initial visit to 20 Chicago area vascular surgeons and are diagnosed with intermittent claudication (IC). Approximately 450 of these patients are expected to undergo surgical bypass or endovascular procedures annually. The primary objectives of this study are 1) to model selection for treatment, 2) to evaluate the effects of smoking and exercise habits on outcomes for treated and untreated patients, and 3) describe and evaluate the clinical and functional outcomes within and between treatment groups. Results will aid patient and surgeon decision-making by simultaneously identifying predictors of good and bad outcomes for both treated and untreated claudication patients. All patients who participate will be surveyed at baseline and during home visits at 6, 12, and 18 month intervals by project home health nurses. The survey will include the SF36 health status instrument, additional disease-specific questions on social support, symptom status and symptom significance, a validated questionnaire on community walking speed and distance, a comorbidity checklist, and questions on satisfaction with treatment decisions. Home visits will include no-cost non-invasive Doppler ankle pressure and wave form analysis. Additional clinical data, including procedure-specific rates of hospital complications, will be abstracted from patients' office, blood flow lab and hospital records. Participating surgeons' attitudes towards the risks and benefits of interventional therapies for IC patients will also be surveyed. Treatment selection will be modeled as a function of patients' socio-demographic and insurance characteristics, peripheral vascular disease severity and location, leg symptom status, duration and significance, comorbid conditions, medications, exercise and smoking habits. This would be the largest, most diverse comparative study of the outcomes of standard treatment for IC to be undertaken in the United States.