The Association Between Pressure Ulcer Development And Patient Comorbidities In Varied Care Settings: A Review Of The Literature

Keywords

Cardiac Disease; Comorbidity; Diabetes Mellitus; Pressure Ulcer; Renal Disease; Respiratory Disease; Underlying Disease

Introduction

A pressure ulcer (PU) is defined 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”[1]. In addition to such mechanical forces, however, patient comorbidity or an underlying disease may also contribute to PU development. Several clinical guidelines for PU prevention refer to comorbidity as a risk factor for PU development, citing, for example, diabetes mellitus [1-4], circulatory disease [1], spinal cord injury [2,4], hip fracture [4], cerebrovascular disease [4], etc. In addition, risk assessment scales for PU prevention such as CBO [5], Spinal Cord Injury Pressure Ulcer Scale (SCIPUS) [6], SCIPUS-A [7] and Waterlow [8] include factors related to patient comorbidities such as diabetes mellitus, and pulmonary and cardiac diseases.

PUs can develop in patients placed in any types of care setting. The aim of this paper is to review the previous English-language literature investigating the association between patient comorbidities and PU development. The author classified the literature into five categories according to the type of care setting, namely the nursing home, hospital, perioperative, rehabilitation,and home settings, and further examined the kind of PU-related comorbidity in each of these settings.

Nursing Home Setting

Nursing homes constitute representative long-term care settings for the immobile or inactive elderly population. The previous literature dealing with the association between comorbidities and PU development in nursing homes is summarized in Table 1. To the author’s knowledge, seven studies have been published to date on this subject [9-15], three cohort studies [10, 13, 14] and four cross-sectional studies [9, 11, 12, 15], all of which utilized large databases at multiple facilities. It should be noted that six of the seven studies cited [9, 11-15] concluded that diabetes mellitus was associated with PU development. Moreover, in some studies, hip fracture [13], Parkinson’s disease [9], and peripheral vascular disease were also listed as risk factors, while other studies showed inverse results [9, 11, 12, 14].

Hospital Setting

Inpatient hospital care ranges from acute or intensive care to chronic or geriatric care. Accordingly, hospitalized patients may present many types of comorbidities in association with PU development. As shown in Table 2, we found three cohort studies [18-20], three cross-sectional studies [16, 21, 22], one cross-sectional/ cohort study [17], and one case-control study [23], or a total of eight studies dealing with PU-related comorbidities in the hospital setting. Three of these studies [21-23] utilized a large inpatient database derived from multiple facilities. On the other hand, six [16-20] utilized relatively small samples from single hospitals including two teaching hospitals [16, 19], two chronic care hospitals [17, 18], and one medical ICU in a public hospital [20]. In four of the studies [17, 21-23], diabetes mellitus was described as a risk factor for PU development, although the remaining four studies denied this association [16, 18-20]. Additionally, anemia [20], cerebrovascular disease [17, 22, 23], chronic heart failure [22, 23], chronic obstructive pulmonary disease [23], fracture [16], osteomyelitis [22], pneumonia [22], renal failure [22], respiratory failure [22], sepsis [22], spinal cord injury [21], and urinary tract infection [22] were mentioned as risk factors for PU development.

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NMES IPC (Institutional Population Component of the National Medical Expenditure Survey): A nationally representative sample of residents in nursing homes.
MDS+ (Minimum Data Set Plus): The expanded version of a national resident assessment instrument specifically for Multistate Nursing Home Case Mix and Quality Demonstration Project.
MDS (Minimum Data Set): A valuable tool for assessing the quality of nursing home care containing clinical information describing the health status of all nursing home residents.

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CHARS (Comprehensive Hospital Abstract Reporting System): The annual data from all hospital admissions in the Washington state.
NIS (Nationwide Inpatient Sample): A national sample of inpatient discharge data.
MPSMS (Medical Patient Safety Monitoring System): A nationwide surveillance system within the hospitalized fee-for-service Medicare population.

Perioperative Setting

Patients who undergo a lengthy operation are potentially at high risk for PU development because repositioning may not be possible for several hours during the intraoperative and postoperative periods. The author has found 10 studies to date concerning PU-related comorbidities in the perioperative setting [24- 33], including nine cohort studies [24- 31, 33] and one meta- analysis [32] (Table 3). Eight of these studies were based on data from a single hospital [24- 29, 31, 33]. Some studies targeted patients who received cardiac surgery [24, 25, 27] or hip fracture surgery [29, 30]. In seven of nine cohort studies [24- 26, 28- 32], diabetes mellitus was identified as a risk factor for PU development. This result was strongly supported by one recent meta-analysis [32] involving six observational studies with a total 2453 patients; when compared to patients with normal glucose tolerance, patients with diabetes mellitus were more likely to develop PUs (odds ratio=2.15, 95% confidential interval: 1.62-2.84). In addition, other comorbidities including cardiac disease [27, 30, 33], renal failure [33], respiratory disease [24, 30, 33], and spinal cord injury [28] were also described as risk factors.

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UDSMR (Uniform Data System for Medical Rehabilitation): A large nongovernment registry for standardized medical rehabilitation information.

Rehabilitation Setting

Because of restrictions on mobility, patients undergoing rehabilitation are thought to be at extremely high risk for PU development. Table 4 lists four studies, including three case-control studies [6, 34, 36] and one cohort study [35], investigating PU-related comorbidities at rehabilitation facilities [6, 35- 37]. Among these, three studies utilized data obtained from a single hospital [6, 34] or small number of hospitals [35], while one utilized a large inpatient database [36]. Two studies targeting patients admitted to spinal cord injury units [6, 35]. Diabetes mellitus [6, 36] and pulmonary disease [6, 35] were each found to be risk factors for pressure ulcer development in two studies. Additionally, cardiac disease [6], dementia [36], peripheral vascular disease [36], and renal disease [6] were also listed as risk factors.

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GPRD (General Practice Research Database): a large outpatient record database from the United Kingdom.

Home Setting

Although most cases of PUs occur in acute or longterm care settings, some also occur in the home setting. The author found one cohort study [37] using a large outpatient record database that investigated the risk factors for PU development (Table 5). This study suggested the following comorbidities as risk factors: Alzheimer’s disease, cerebral vascular events, chronic obstructive pulmonary disease, congestive heart failure, diabetes mellitus, deep venous thrombosis, hip fracture, limb paralysis, lower limb edema, malignancy, osteoporosis, Parkinson’s disease, rheumatoid arthritis, and urinary tract infection.

Discussion And Summary

PUs can develop in various care settings. In this paper, we categorized the relevant literature published to date on the subject according to five types of care setting. Importantly, patient background, study design, sample size, and risk factor variables varied widely in each study. Moreover, a large dispersion of the results was seen between the studies, even in the same setting. For this reason the author concluded that the outcomes from each study mentioned above are in some instances not amenable to comparison. Nonetheless, among the numerous comorbidities referred to in these studies, diabetes mellitus seemed to present the strongest association, with half or more of the studies in all of the care settings and one meta-analysis pointing to this condition as a risk factor for PU development. With respect to other comorbidities, cardiac, renal, and respiratory disorders were commonly found to be risk factors in four of the five care settings: hospital, perioperative, rehabilitation, and home. However, the author could not find a clear difference in the kinds of PU-related comorbidities between settings.

In summary, the findings of previous studies investigating risk factors for PU development underscore the importance of recognizing patient comorbidities in order to prevent PUs. Despite the large dispersion seen between the study results, diabetes mellitus, cardiac disease, renal disease, and respiratory disease were found to be risk factors across a variety of settings.