Hospital-Acquired Pressure Ulcers

Results From the National Medicare Patient Safety Monitoring System Study

Courtney H. Lyder, ND; Yun Wang, PhD; Mark Metersky, MD; Maureen Curry, MHA; Rebecca Kliman, MPH; Nancy R. Verzier, MSN; David R. Hunt, MD


J Am Geriatr Soc. 2012;60(9):1603-1608. 

In This Article


The data from this study revealed that HAPUs remain a significant problem for hospitalized individuals. Although a 4.5% HAPU incidence rate and 5.8% prevalence rate on admission were found, no other large Medicare studies were located to place these findings into context of the current literature. The between-state incidence rate variance was 3.2% (P < .001). Thus, to benchmark appropriately, it is imperative for hospitals to be cognizant not only of the national incidence rate, but also of their own state's rates. Several states mandate that hospitals track and report their PU rates to their state departments of health, but it is often difficult for hospital staff to obtain access to relevant benchmarks for comparison between "like minded" hospitals within the state. Thus, this study provides a glimpse of PU incidence and presence at the state and national level for Medicare beneficiaries. Most prevalence studies use a 1-day period to determine community-acquired PU rates for the hospital, with some studies reporting hospital PU prevalence rates of as high as 15%.[12–14]

The large difference between the 15% reported in the research literature and the 5.8% found in the current study may be because, when a 1-day prevalence is used, individuals with longer hospital lengths of stay are more likely to be counted. Another explanation for this difference is that the majority of prevalence studies reported are completed during hospitalization, versus the current study, which counted on PUs on admission and HAPUs. The findings from the MPSMS have also demonstrated that individuals with HAPUs have much longer hospital lengths of stay. Thus, a 1-day prevalence study (often used by hospitals to determine prevalence rates) may not be an accurate reflection of individuals who developed HAPUs during their stay.

The findings of the current study support current literature that suggests that specific chronic diseases such as CHF, COPD, CVD, diabetes mellitus, obesity, and use of corticosteroids may increase vulnerability to the development of HAPUs.[15,16] Thus, individuals entering the hospital with a constellation of these conditions should be identified as being at higher risk for developing HAPUs.

The majority of participants developed HAPUs over the coccyx and sacrum, hips and buttocks, and heels. These findings support the analyses by the National Pressure Ulcer Advisory Panel (NPUAP).[14] Obesity was associated with HAPUs. Chronic impairment of systematic perfusion that occurs in individuals who are obese frequently results in chronic skin and wound problems.[17] Blood supply to fatty tissue may not be adequate to provide appropriate oxygen and nutrition. This could be further compounded if the individual's dietary input does not include essential vitamins and nutrients.

HAPUs also have been shown to be an important risk factor associated with mortality. The MPSMS PU findings strengthen the body of research that suggests that individuals with HAPUs have higher mortality in the hospital and within 30 days of discharge. Therefore, hospitals should identify individuals at high risk for HAPUs and implement preventative interventions on admissions accordingly. It could be argued that, because of the good PU prevention programs being implemented in hospitals throughout the United States, rates of 4.5% might be acceptable.[18,19] These findings also suggest that HAPUs may develop independent of good care being provided.[20,21] Thus, some HAPUs may be unavoidable, as suggested by the NPUAP[22] and other national associations.[23,24]

There were several limitations inherent in the MPSMS PU study. Retrospective abstraction of medical records is a limitation in data collection because it is possible that HAPUs could have been present and simply not recorded or adequately described. In several cases, the clinician did not document PUs, yet based on clinical characteristics and the location and description of the ulcer, the research team decided to count these as HAPUs. There is a slight possibility (highly unlikely) that these were not HAPUs. Care was taken to exclude all other chronic ulcers based on medical diagnoses in the medical records and using ICD-9 coding (e.g., diabetic ulcers, venous stasis ulcers, arterial ulcers). To distinguish individuals with HAPUs from those with PUs already present on admission, no PUs, new or old, found in the same body region as a PU already present on admission were counted as HAPUs. This approach may have led to undercounting the number of individuals who developed new HAPUs during the hospital stay.

The inability to capture the staging of HAPUs was another limitation. The variability of documented staging of HAPUs in the medical record made this variable unreliable. Staging of PUs using the NPUAP staging system is not required. Given the new CMS Hospital-Acquired Conditions, under which hospitals will no longer be reimbursed for Stage 3 and 4 PUs unless they were identified upon admission, accuracy in staging of these ulcers may improve. That is, clinicians may need to be reeducated on staging of PUs using the 2007 NPUAP staging system because correct staging of PUs is necessary to make appropriate choices in their management of the PUs. Although several undesirable outcomes were associated with the development of HAPUs, no assertion is made that there was a causal relationship between the development of HAPUs and these outcomes. Nonetheless, describing these associations is important to help identify high-risk individuals. For example, even though it cannot be stated that HAPUs directly contributed to the longer hospital length of stay, these findings suggest that an individual with a prolonged hospital length of stay is at greater risk of developing HAPUs and that both add financial burden to the hospital. Hospitals should use the MSPMS PU data as one point of comparison, but hospitals may have different rates because of differences in patient acuity, so the data from the current study may or may not indicate that institutional improvement in PU prevention is warranted. The data support that multiple chronic conditions or any combination of these conditions may contribute to the development of HAPUs. Perhaps these conditions lead to readmission and HAPUs are merely a surrogate for identifying very sick people rather than being a causative factor for readmission. Thus, data on the incidence and prevalence of PUs must not simply be collected; understanding of the underlying diseases that may lead to HAPUs must be gained.

Regardless of the limitations, the MPSMS PU study has major strengths. To the best of the knowledge of the authors, this is the first study to use data abstracted directly from medical records to assess HAPUs in hospitalized Medicare beneficiaries at the national and state levels. With the use of an evidence-based algorithm developed by nationally recognized experts, the MPSMS is the largest database of its kind. The PU findings have important clinical and public health implications. MPSMS PU findings clearly guide clinicians to anatomical sites where PUs are most likely to develop and identify critical characteristics and conditions that increase the risk of HAPUs in Medicare beneficiaries. The findings suggest that these individuals are more likely to die or be readmitted within 30 days. It was surprising that the Northeast region had higher rates of HAPUs. The aggressive prevention and recognition programs occurring in the Northeast region may lead to higher rates being reported than in other regions, which may explain this in part.[25–27] Regardless, with these data, it is now possible for hospitals to benchmark their Medicare beneficiaries' HAPU rates at the national and state levels.