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Epidemiology, pathogenesis and risk assessment of pressure ulcers

Dan Berlowitz, MD, MPH
Section Editors
Kenneth E Schmader, MD
Hilary Sanfey, MD
Deputy Editor
Kathryn A Collins, MD, PhD, FACS


Pressure ulcers are lesions caused by unrelieved pressure that results in damage to the underlying tissue. Generally, these are the result of soft tissue compression between a bony prominence and an external surface for a prolonged period of time [1,2]. The consequences of pressure-induced skin injury range from nonblanchable erythema of intact skin to deep ulcers extending to the bone.

The ulcer imposes a significant burden not only on the patient, but the entire health care system. Reducing the frequency of pressure ulcers is an important component of current goals for patient safety as evidenced by the Institute for Healthcare Improvement (IHI) 5 Million Lives Campaign, and the decision by the United States Center for Medicare and Medicaid Services to not reimburse hospitals for the treatment of hospital-acquired pressure ulcers [3-5].

Knowledge of factors contributing to the pathogenesis of pressure ulcers allows the identification of patients at risk for ulcer development such that preventive measures may then be targeted to those specific patients. The epidemiology, pathogenesis, risk factors, and risk assessment of pressure ulcers will be reviewed here. Prevention and treatment are discussed separately. (See "Prevention of pressure ulcers" and "Clinical staging and management of pressure-induced injury".)


Pressure ulcers are among the most common conditions encountered in acutely hospitalized patients or those requiring long-term institutional care. The incidence of pressure ulcers varies widely by clinical setting [6-8]. An estimated 2.5 million pressure ulcers are treated each year in acute care facilities in the United States alone [6,7].

Methods of studying and reporting pressure ulcer incidence include direct patient examination [9], use of databases [10], and surveys [11]. These studies tend to be small, and often involve only a single facility, making generalizability uncertain. Caution is required when interpreting the reported incidence and prevalence rates for pressure ulcers since the methodology and duration of follow-up varies between studies. The most accurate estimates are derived from studies where clinician-researchers have directly examined the patients. Studies have also differed on whether they included superficial ulcer stages (stage 1 ulcers (table 1)). Although stage 1 ulcers are frequently encountered, many epidemiological studies have elected not to include them since they are difficult to reliably detect.


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Literature review current through: Sep 2016. | This topic last updated: Apr 11, 2016.
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