The National Pressure Ulcer Advisory Panel5 (NPUAP) defines a pressure ulcer as “localized injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure, or pressure in combination with shear and/or friction.”
Although the NPUAP recently changed the term pressure ulcer to pressure injury, the term pressure ulcer is used throughout this article to maintain consistency with the ICD-9 coding used during the study period.
Pressure ulcers occur in up to 23% of patients in long-term and rehabilitation facilities6 and at an incidence of 10% to 41% in ICU patients.7,8 The AHRQ2 reported nearly 2.5 million individuals are affected by pressure ulcers, and more than 60 000 patients9 in the US die each year as a direct result of pressure ulcers. The costs associated with pressure ulcers are considerable. According to a 1996 prospective, year-long study looking at 30 patients and conducted by Xakellis and Franz,10 the incremental cost per pressure ulcer in the US was $2731. Per a retrospective review,11 the cost could be as high as $59 000 if the ulcer was associated with osteomyelitis. Medicaid9 estimated each pressure ulcer adds $43 180 in costs to an individual’s hospital stay.
Pressure ulcers also have a significant impact on patient morbidity, mortality, and quality of life.2 In their review of pressure ulcers in intensive care patients, Burdette and Kass12 described pressure ulcers as one of the most expensive and debilitating diseases in the 20th century. In her review of risk factors and the assessment of pressure ulcer risk assessment, Braden13 indicated the complexity of the management and treatment of pressure ulcers can greatly reduce the quality of life, resulting in a worldwide economic dilemma. Similarly, in their retrospective review of the 2003 NIS database, Fogerty et al14 demonstrated the complexity of pressure ulcer development and the multiplicity of contributing risk factors.
The overall incidence and prevalence of pressure ulcers have been shown in 2 reviews of the literature15,16 to remain high in the US despite the supposed improvement in the quality of health care in general and the drastic improvement in understanding these ulcers or the improvements in technologies available for prevention of ulcers specifically. The current study found the annual number of pressure ulcers reported in the US inpatient population was 670 767. Overall, the number of annual cases has remained constant at approximately 600 000 to 700 000 patients during the 5-year period of the study, with a rate of 1.8%. These numbers are lower than the 2.5 million reported by the AHRQ9 due to the fact the NIS database only accounts for those individuals with pressure ulcers who were hospitalized. Advances in pressure ulcer management have enabled these patients to receive treatment in outpatient care centers, with the goal of decreasing the duration of hospitalization, readmission rates, additional patient morbidity, and total care costs.9
In the opinion of the authors, the observed absence of a decrease in pressure ulcer rates may be attributed to: 1) failure or inadequate application of available prevention strategies during hospital admission or in other patient care environments, or 2) improvements in pressure ulcer assessment and reporting.
Risk factors. Conflict exists as to whether pressure ulcers result from factors largely dependent on caregivers or primarily from factors associated with patient morbidity. It is well established that pressure ulcers continue to be a common health problem, particularly among individuals with physical limitations or persons who are elderly and bedridden.
Age. Perneger et al17 evaluated the incidence of pressure ulcers (N = 2373) by conducting 3 cross-sectional surveys in a teaching hospital among patients with no pressure ulcer documented on admission. The authors assessed the development of pressure ulcers and the date on which the ulcer was documented and correlated this with diagnosis and reason for admission, among other factors. They found 247 new pressure ulcers occurred during admission (5.7 per 1000 person-days). The risk of pressure ulcer occurrence increased with age (11.2% of patients ages 70 to 79 years versus 34% in patients >90 years). Their results are consistent with the current study where the mean overall age of patients with a pressure ulcer was 71.2 years (68 years in men and 74 years in women), with increasing rates in older age groups. Jaul18 described pressure ulcers as chronic and healing in the geriatric population; the author indicated the presence of a pressure ulcer constituted a “geriatric syndrome” that was a result of multiple factors: immobility, poor nutrition, aging skin with poor elasticity, and numerous chronic diseases.
The US is experiencing a significant increase in the aging population. By the year 2050, the population 65 years of age and older will nearly double. This creates an urgent need for better prevention strategies and management of pressure ulcers.
Gender. In the current study, the prevalence of pressure ulcers was significantly higher in men (2%) than women (1.6%) (OR: 1.282, 95% CI: 1.276-1.288, P <0.001). Inconsistent conclusions have been drawn as to which gender has a higher predilection for pressure ulcer development. The Waterlow score,19 developed in 1987 as a tool for pressure ulcer risk assessment, accommodates for research showing women are at a greater risk for development of a pressure ulcer; female gender is assigned a score of 2, where men are assigned a score of 1. This scoring system accounts for gender differences in the observation of predisposition of women to pressure ulcers in individuals who had femoral fractures.20 Similar results were found in a 2-phase epidemiological study (N = 327 patients) by Bale et al21 that looked specifically at hospice patients. In addition, the authors found decreased pressure ulcer development with the use of a risk assessment tool and subsequent proactive measures such as offloading surfaces. Contrarily, in a prospective cohort study (N = 258), Primiano et al22 observed higher rates of pressure ulcers in men. The authors evaluated preoperative, intraoperative, and postoperative risk factors in cases where surgery lasted >3 hours; using bivariate and logistic regression analyses, male gender was found to be predictive of pressure ulcer development. The authors suggested the difference in distribution of adipose tissue in females was protective against pressure ulcer development. The current authors think the higher prevalence among male patients can be attributed to other associated risk factors as opposed to gender predilection. A multicenter cohort study of 3361 patients by Chen et al23 noted the higher number of spinal cord injuries observed in men could result in more pressure ulcers when compared to women. Gibson et al24 observed similar results in their 2002 qualitative study. The Braden scale25 does not recognize any difference in pressure ulcer risk associated with gender, which is in accordance with other prevalence/incidence research.26,27 A review28 of risk assessment found gender difference observed in pressure ulcer development also could be a reflection of the complexity of the overall problem, the multitude of causative events and comorbid conditions, and the lack of a universal risk assessment/classification tool.27
Race/ethnicity. In the US, race/ethnicity, low socioeconomic status, occupation type, and education are consistently related to reduced access to quality health care. Previous studies have reported a significant association between race/ethnicity and pressure ulcer development: a qualitative study by Saladin and Krause29 conducted among post spinal cord injury patients of varying racial-ethnic backgrounds (105 American Indian, 127 Caucasian, 122 Hispanic, 121 African American) found variability in access to treatment may lead to minority populations experiencing higher pressure ulcer prevalence. A cross-sectional study30 found African American ethnicity was a predictor of pressure ulcer recurrence. However, Furher et al31 found no differences in the prevalence of pressure ulcers between African Americans and Caucasians in the general population, although they reported African Americans suffered greater pressure ulcer-related mortality and suffered from more severe, higher-staged ulcers. An age-adjusted descriptive study using matched odds ratio comparisons by Redelings et al32 found African Americans had higher mortality from pressure ulcers than Caucasians. In general, African Americans tend to have less education and higher poverty rates at all ages compared to Caucasians, as shown by the survey analysis of health disparities using the US National Health and Nutrition Survey and follow-up interviews conducted by Farmer and Ferraro.33 The results were no different in the current study: pressure ulcer incidence rates were higher in African Americans (2.4%, n = 119 113 out of 4 979 112) compared to all the other races (P <0.05). Caucasians had the second highest incidence rate (1.8%, n = 407 006 out of 22 621 329) compared to other minority races such as Native American (1.4%), Asian/Pacific Islander (1.3%), Hispanic (1.2%), and other races (1.4%).
Insurance. In November 2008, the CMS instituted a policy to withhold reimbursement to acute care hospitals for the costs of treating hospital-acquired conditions such as pressure ulcers.34 Despite these policies, pressure ulcer rates were the highest in persons with Medicare coverage (3.5%, P <0.05). The prevalence rates for patients with Medicaid, private insurance, and self-pay patients were 0.8%, 0.6%, and 0.4%, respectively. The high rate of pressure ulcers in Medicare patients may be attributed to the fact that persons eligible for Medicare are 65 years or older, which subsequently places them at higher risk for development of pressure ulcers according to the literature and the current study results.
Nutrition. According to a descriptive analysis by Duncan35 and a review by Lyder and Ayello,36 immobility, inadequate nutrition, sensory deficiency, multiple comorbid conditions, circulatory abnormalities, dehydration, age, and incontinence are a few of the more than 100 factors identified as placing adults at risk for developing pressure ulcers. Of all the risk factors, malnutrition contributed the most significantly to pressure ulcer prevalence in the current study (11.5%, RR = 8.45, CI: 8.41-8.5, P <0.001). Compromised nutritional status such as unintentional weight loss, undernutrition, protein energy malnutrition, and dehydration are known risk factors for pressure ulcer development.37 As shown in a pilot study38 and a retrospective cohort study,39 additional nutrition-related risk factors associated with increased risk of pressure ulcers include low body mass index, reduced food intake, and impaired ability to eat independently. These factors might reflect poor health and self-care that is associated with higher incidence of pressure ulcers.
Tissue perfusion. Reduced tissue perfusion is known to play an important role in the development and chronicity of pressure ulcers. Mechanical loading may be significant enough to compromise the capillary circulation, causing ischemia and cell death in areas of pressure and, subsequently, ulcer development. Hypotension and PVD play a similar role. In a retrospective cohort study by Man et al,40 hypotension was found to be an important risk factor for pressure ulcer development in the geriatric population. In the current study, rate of pressure ulcers was high in patients with hypotension (5.5%; RR = 3.56, CI: 3.53-3.38, P <0.001) and PVD (5.1%; RR = 3.22, CI: 3.19-3.24, P <0.001).
pH. The pH of normal skin (pH 5.4–5.9) has a bactericidal effect and limits the growth of pathogenic organisms. In the event of urinary incontinence, due to reasons such as CVD, urinary urea decomposes on the skin to form ammonium hydroxide, which raises the skin pH and favors bacterial proliferation. A descriptive study by Leveen et al41 also shows high pH also negatively impacts the delivery of oxygen to damaged tissue, making wound healing even more challenging. Fecal incontinence also can cause skin irritation and breakdown. The current study showed patients with CVD had a pressure ulcer rate of 3.8% (RR = 2.46, CI 2.44-2.48, P <0.001), and the rate was 5.4% rate (RR = 3.16, CI: 3.12-3.21) among persons with incontinence.
Diabetes and fractures. Other factors that may contribute to pressure ulcer development include diabetes and fractures. Blood sugar control is known to play an important role in wound healing. Persons with diabetes are at risk for developing both pressure ulcers and diabetic foot ulcers, owing to the neuropathy and tendency for unnoticed trauma. In the current study, the rate of pressure ulcers among patients with diabetes was 3.2% (RR = 2.38, CI 2.37-2.39, P <0.001). A retrospective review of data42 found fractures that result in immobilization, such as hip42 and femur20 fractures, predispose to the development of pressure ulcers. In the current study, patients with fractures had a pressure ulcer rate of 2.7% (RR = 1.56, CI 1.54-1.58, P <0.001).
Ulcer quantity, site, and stage. Documenting the number, site, and stage of ulcers is crucial in pressure ulcer management. Among the 676 435 patients studied in this NIS database, 540 073 (79.8%) had 1 ulcer recorded, 105 383 (15.6%) had 2 pressure ulcers, and 30 979 (4.6%) had more than 2 ulcers. Bony prominences are more susceptible to pressure ulcers as a result of deformation of deep tissues and muscle atrophy. A review of the literature43 found shear force and friction injury to skin surfaces create a process in which the epidermal and dermal layers adhere to bed surfaces causing destructive events to the underlying areas of the skin. The most vulnerable pressure points depend on the position in which most of the patient’s time is spent. The current data showed a majority (47%) of the pressure ulcers were located on the patients’ lower backs (sacrum). Excessive moisture results in hyperhydration of the skin, rendering it more vulnerable to dermal erosion. The high percentage of lower back pressure ulcers could be an amalgamation of the influence of shear force, friction, and moisture in patients who are bedbound. Patients also had pressure ulcers on the heel (14%), hip (5%), and other locations (9%). The ankle, upper back, elbow, and locations not otherwise specified each accounted for <5%. A systematic review of the literature44 (including 3 RCTs and 1 economic study [N = 502]) recommends manual repositioning of these patients for both treatment and prevention of pressure ulcers. However, the ideal repositioning regimen and frequency has yet to be determined, per a systematic review by Moore and Cowman.45
Pressure ulcer staging affects both treatment and prognosis. The NPUAP46 redefined the stages of pressure ulcers in 2007 to include the original 4 stages plus 2 additional stages (deep tissue injury and unstageable). The reported incidence of pressure ulcers Stage 2 or greater is between 8.1% and 12.9%.47,48 The current data analysis showed both male and female patients had a median pressure ulcer Stage 2. Among Caucasian and other populations, the median stage of pressure ulcers was Stage 2, whereas the median stage for the African American population was Stage 3. The advanced stages seen in African Americans may be attributed to poor general condition or due to difficulty in detecting early pressure ulcers stages due to the clinical difficulty in observing erythema and blanching response in dark skin. The current authors observed patients who suffer from malnutrition had a median ulcer stage of 3, and patients with diabetes, CVD, incontinence, PVD, and hypotension had a median ulcer stage of 2. This could be attributed to frequent surveillance for pressure ulcers in these high-risk patients in nursing homes and hospitals.
For Stage 1 and Stage 2 pressure ulcers, wound care typically does not involve surgery. Management at these stages may involve topical therapy, offloading, and optimization of nutrition/moisture management, as well as proper management of the underlying cause. For Stage 3 and Stage 4 ulcers, surgical intervention may be required, although a review49 has shown some of these lesions might be treated conservatively due to coexisting medical problems. Generally, excisional surgical debridement is the standard care for higher-stage pressure ulcers because these often present with necrosis. In the current data, a total of 71 418 excisional debridement procedures were performed in 65 582 patients; of those, 5462 patients required multiple debridement procedures.
LOS. According to a limited literature review,50 prolonged LOS is a significant predictor of functional decline in elderly individuals during hospitalization. A 9-year, prospective observational registry study of 275 pressure ulcers by Lardenoye et al51 showed 5.5% of all pressure ulcers resulted in prolonged hospitalization and found a strong correlation among pressure ulcer development, reason for hospital admission, gender, and age. In a cross-sectional, observational study (N = 2000), Graves et al52 concluded the presence of pressure ulcers was a significant independent contribution to excess length of hospitalization. LOS has been shown to be prolonged an average range of 4 to 6 days, including in the descriptive, comparative study of 2 cross-sectional pressure ulcer surveys52,53 by Gunningberg and Stotts.54 The current study shows the median LOS for individuals with at least 1 pressure ulcer was 7 days (mean 11.1 ± 15) compared to a median of 3 days (mean 4.6 ± 6.8) in patients without pressure ulcers. Patients with significant weight loss, paralysis, coagulopathy, CHF, fluid and electrolyte disorders, and pulmonary and circulation diseases with concurrent diagnosis of at least 1 pressure ulcer were more likely to have a longer LOS.
Cost. Prolonged LOS not only affects the morbidity and mortality of patients, but it also has a significant impact on hospital charges. The current study estimated the median TC to be $17 200 (mean $32 200 ± $57 500) in patients without pressure ulcers. In contrast, the median hospital charges for patients with pressure ulcers were significantly higher at $36 500 (mean $ 72,000 ± $122 900, P <0.001). Along with pressure ulcers, increased LOS (coef = 8613), male gender (coef = ,464), African American race (coef = 3483), private insurance beneficiaries (coef = 7643), and Medicaid beneficiaries (coef = 3729) significantly impacted total hospital charges. Other conditions that contributed to increased hospital charges were pulmonary/circulation disease (coef = 7062), PVD (coef = 5887), obesity (coef = 4229), hypotension (coef = 2530), and fluid and electrolyte disorders (coef = 3971).
Mortality. Pressure ulcers play a significant role in influencing the mortality rate among hospitalized patients and patients in nursing facilities. A retrospective study by Lyder et al55 showed that of 3000 individuals who entered the hospital with a pressure ulcer, 16.7% developed at least 1 new pressure ulcer during their stay. The odds of any patient dying in the hospital were 2.8 times higher if the patient had a pressure ulcer. In the current study, the mortality rate in patients with pressure ulcers was significantly higher than in patients without pressure ulcers (9.1% versus 1.8%, OR = 5.08, CI: 5.03-5.1, P <0.001). The current data analysis also showed 72.5% of patients without pressure ulcers were discharged home compared to 13.4% patients with pressure ulcers (OR 5.42, CI: 5.39 – 5.45, P <0.001). Furthermore, 76.9% patients with pressure ulcers were transferred to a skilled nursing facility or intermediate care facility or required home health care compared to 24.7% patients without pressure ulcers (OR = 3.116, CI: 3.112-3.121, P <0.001). This observation is consistent with previous reviews.56,57 The additional fees for skilled nursing facilities add to the increase in health care expenditure on treatment and management of this preventable health issue.