The Sage Group

THE SAGE GROUP Reports that in 2006 Approximately 2 Million People in the United States Suffered from Critical Limb Ischemia

ATLANTA, April 17, 2007–(BUSINESS WIRE–A recent analysis published by THE SAGE GROUP concluded that an estimated 2 million people in the U.S. have critical limb ischemia (CLI). Reflecting the ageing population, this number is projected to grow to almost 2.8 million by 2020. However, if the prevalence of diabetes continues to increase, there could be over 3.5 million cases of CLI by 2020.

“The societal costs and economic consequences of 2 million people with critical limb ischemia are profound,” declared Mary L. Yost, President of THE SAGE GROUP.  “Additionally, there are significant implications for pharmaceutical and interventional markets. For example, if all CLI patients are diagnosed and receive the appropriate treatment, the potential market for endovascular products alone is $2.9 billion,” continued Yost.

Ms. Yost explained that CLI prevalence was calculated based on “the diabetes method.” “The diabetes method begins with segmenting the population age 45 and older by age and glucose status, calculating the prevalence of PAD in each segment and then estimating the prevalence of critical limb ischemia in each,” she elaborated.

“Diabetics represent the majority of CLI patients, accounting for 60% to 80% of the total. In the absence of U.S. population-based studies, we believe that this method may provide the most accurate estimates of critical limb ischemia prevalence,” stated Yost.

According to Yost, “Research on the epidemiology of critical limb ischemia remains sparse. Population-based research regarding the U.S. prevalence of CLI appears to be nonexistent. In addition to lack of U.S. data, there appears to be no global data on the number of people suffering from CLI.”

“To date the number of U.S. citizens suffering from CLI has been estimated employing data from five published papers,” observed Yost. “The most commonly cited figures are based on one of the following: estimated number of amputations; CLI incidence in the U.K. and Ireland based on a 1995 survey of vascular surgeons; estimated progression from intermittent claudication (IC) or on a combination of amputations, revascularizations and progression from IC in Italy,” she continued.

“CLI represents ‘end-stage’ Peripheral Arterial Disease (PAD),” explained Ms. Yost. PAD is characterized by a reduction of blood flow to the lower limbs due to atherosclerosis, commonly called hardening of the arteries. Atherosclerosis is a disease in which the walls of the arteries thicken and harden as a result of the build-up of fatty deposits (plaque) on their inner lining.

In critical limb ischemia blood flow is so inadequate that ulcerations and gangrene occur. Once PAD has progressed to CLI, the risks of limb loss and mortality increase. At six months approximately 20% of those with CLI will die; another 40% will experience amputation.

According to THE SAGE GROUP, approximately 160,000 PAD-related amputations are performed annually in the U.S.

The report titled ‘Critical Limb Ischemia Volume I, United States Epidemiology’ is the first of three to be published on CLI. The second report focuses on CLI epidemiology in the largest international markets.

The primary purposes of CLI Volume I were to estimate the number of people with CLI in the United States, to assess the market opportunities and to determine the most appropriate methods for estimating the prevalence of critical limb ischemia in the largest international markets.

CLI Volume I provides a comprehensive analysis of all relevant research relating to CLI prevalence and incidence as well as an assessment of the applicability to the U.S. population. Because diabetes and chronic kidney disease are both highly prevalent in the critical limb ischemia population, research relating to these two risk factors is discussed in great detail.


THE SAGE GROUP, an independent research and consulting company, specializes in atherosclerotic disease in the lower limbs, specifically PAD (Peripheral Arterial Disease), CLI (Critical Limb Ischemia) and ALI (Acute Limb Ischemia).

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