2010 BC Guide in Determining Fitness to Drive

Deep-vein thrombosisDeep-vein thrombosis (DVT) occurs when a thrombus (blood clot) forms within a deep-vein,most commonly in the calf. Three main factors (known as Virchow's triad) can contribute todeep-vein thrombosis: injury to the vein's lining, an increased tendency for blood to clot, andslowing of blood flow.12.2 Prevalence and incidence of peripheral vascular diseasesPeripheral arterial diseaseEstimates of the prevalence of PAD depend on populations studied and study methodology. Thegeneral prevalence rate is reported to be 10%. However, because most individuals remainasymptomatic, the true overall prevalence rate is likely to be considerably higher. Theprevalence of PAD increases with age and with prolonged exposure to smoking, hypertension,and diabetes.Recent studies indicate that PAD affects approximately 20% of adults 55 years of age and olderand an estimated 27 million persons in North America and Europe. Intermittent claudication isthe most common symptom associated with PAD. The prevalence of intermittent claudicationincreases dramatically with age. The incidence in the general population is less than 1% thoseunder the age of 55, and increases to 5% for those 55 to 74 years of age. At younger ages, theprevalence rate is almost twice as high for males as for females, but at the older ages, thedifference between males and females is reduced. Risk factors for PAD are shown in Table 1.Table 1Individuals at-risk for Lower Extremity Peripheral Arterial Disease 5Age less than 50 years, with diabetes and one other atherosclerosis risk factor (smoking,dyslipidemia, hypertension, or hyperhomocysteinemia)Age 50 to 69 years and history of smoking or diabetesAge 70 years and olderLeg symptoms with exertion (suggestive of claudication) or ischemic rest painAbnormal lower extremity pulse examinationKnown atherosclerotic coronary, carotid, or renal artery diseaseAbdominal aortic aneurysmsBased on results from a population-based study completed in 2001, the prevalence of abdominalaortic aneurysms is approximately 9% for males and 2.2% for females. Prevalence increases5 Reproduced, with permission from Hirsch, Haskal, Hertzer et al.. ACC/AHA guidelines for the Management ofPatients With Peripheral Arterial Disease (Lower Extremity, Renal, Mesenteric, and Abdominal Aortic): ExecutiveSummary. Journal of the American College of Cardiology. Available at:http://www.acc.org/clnical/guidelines/pad/summary.pdf113