The Sage Group

THE SAGE GROUP Releases New Estimates for the United States Prevalence of Peripheral Artery Disease (PAD) and Critical Limb Ischemia (CLI)

ATLANTA, September 30, 2010 (BUSINESS WIRE)—According to THE SAGE GROUP, in 2010 almost 18 million U.S. citizens suffer from PAD.Reflecting the aging population this number is projected to increase to 21 million by 2020.

Critical limb ischemia (CLI), the most severe and deadly form of the disease, currently afflicts 2.8 to 3.5 million of those with PAD. By 2020 the U.S. prevalence of CLI is forecast to grow to between 3.6 and 4.5 million.

Commenting on the difference between THE SAGE GROUP’S estimates and the commonly quoted numbers of 8-12 million, Mary L. Yost, President stated, “Our PAD numbers have always been considerably higher and these revised estimates increase the gap even more. We are often asked why?” she said.

According to Ms. Yost, “There are four main reasons: the number of studies reviewed, the types of studies and populations analyzed, the definition of PAD and most importantly the estimation process itself. For example, our estimates are based on review and analysis of over 200 studies conducted in general and primary care populations, as well as in high-risk populations including diabetics, individuals with kidney disease and those ages 65 and older. In contrast, other estimates have been based on specific results found in fewer than 5 studies conducted at a fixed point of time in history.”

“Our estimates are dynamic, changing with the aging population projected by the U.S. Census Bureau and are based on the most recently reported prevalence of diabetes,” Yost explained. “We calculate PAD and CLI numbers based on ‘the Diabetes Method,’ which begins with segmenting the population by age and glucose status then calculates the prevalence of PAD and CLI in each segment,” she elaborated.

“There are numerous large-scale, population-based studies conducted in the U.S., Europe and other countries that provide detailed information regarding the percentage prevalence of PAD by glucose category by age and/or sex,” explained Yost.

Age and diabetes are two significant risk factors for peripheral artery disease. In diabetics ages 50 and older, 30% to 40% suffer from PAD. Diabetics represent the majority of CLI patients, accounting for 60% or more of the total. Sixty to 80% of CLI occurs in those 65 and older.

The U.S. is experiencing an epidemic of diabetes with the fastest increases occurring in senior citizens. According to 2005-2006 National Health and Nutrition Examination Survey(NHANES) data, 31% of those 65 and older have diabetes. “In contrast, our original PAD and CLI estimates were based on about 21% of the elderly population with diabetes. Our new PAD and CLI estimates reflect the higher reported prevalence of diabetes. Nothing else has changed,” Yost observed.

“The social consequences and the economic costs of these PAD numbers are staggering,” Ms. Yost declared.“Using cost data from the U.S. cohort of the REACH (Reduction of Atherothrombosis for Continued Health) Registry, we estimate that in 2004 the annual economic cost of PAD was $102 billion—exceeding the cost of treating coronary artery disease,” she continued.

“PAD is expensive to treat because it is generally not diagnosed or treated until the most severe stages (rest pain, ulcers and gangrene). Then patients require hospitalization for costly revascularization procedures and amputations. In addition, people with PAD suffer disproportionately from other cardiovascular diseases requiring hospitalization for heart attack, stroke and other vascular conditions,” explained Yost.

“Critical limb ischemia estimates are generally nonexistent—except for THE SAGE GROUP’s numbers,” Yost stated. “This is extremely unfortunate. Without realistic, real-time numbers for PAD and CLI, the social and economic burden cannot be accurately assessed. In addition, if the numbers employed are too conservative, then the costs as well as the investment opportunities are significantly understated,” she concluded.


THE SAGE GROUP, a research and consulting company, specializes in atherosclerotic disease in the lower limbs, specifically PAD (Peripheral Artery Disease), CLI (Critical Limb Ischemia) and ALI (Acute Limb Ischemia). The most recent research focuses on PAD and diabetic foot ulcers (DFU).

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