Burden of Pressure Injuries: Findings From the Global Burden of Disease Study

Pressure injuries, also known as decubitus ulcers or pressure ulcers, continue to plague patients and the healthcare community.¹  Despite advances in medicine, the incidence of pressure injuries has remained stable and even slightly increased over more recent years according to some existing literature.^2,3 Multiple studies have attempted to quantify the problem. A meta-analysis by Li et al suggested the global prevalence of pressure ulcer to be 12.8%, with a hospital-acquired pressure injury (HAPI) incidence of 8.4%.² A systematic review by Tubaishat et al estimated a global prevalence in the acute care setting to be between 6 and 18.5%.³

Many believe pressure injury to be a widely preventable disease with much more room for improvement. In fact, there was unanimous consensus by the National Pressure Ulcer Advisory Panel (NPUAP) in 2010 that although not all pressure injuries are avoidable, most are.⁴ The basis for this idea stems from the understanding that the majority of pressure injuries in both the ambulatory and hospital settings, including hospital-acquired pressure injuries, are stage I or stage II. In their global review, Li et al showed that stage I and II ulcers comprised 71.5% of all ulcers.²

Whereas there is a well-known financial burden, relatively little is known about the overall morbidity related to the disease. Additionally, attempting to quantify morbidity objectively can become rather complex. One practical indicator that is often used is the disability-adjusted life year (DALY), which considers both mortality and morbidity.  It is the sum of years of life lost (YLL) due to a disease and years living with the disease (YLD).  The YLL is determined using a standardized life expectancy table based on age at time of death. The YLD is more complex and is a calculation based on the prevalence of the disease and its weighted level of severity.^5,6 Implementation of the DALY as a quantifiable variable has been integral for studies such as the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017).

By extracting data from GBD 2017, this research sought to identify the incidence as well as the burden related to the diagnosis of pressure injury of any stage in the US.

Data Extraction

The data of the Global Burden of Disease Study 2017 (GDB 2017), maintained and distributed by the Institute for Health Metrics and Evaluation (IHME) of the University of Washington, Seattle, was assessed.⁷ GDB 2017 is the result of a consortium of more than 3600 researchers to collect and evaluate information on incidence, mortality, and disability associated with more than 350 diseases and injuries in 195 countries since 1990. GDB 2017 methodology in prospectively capturing, monitoring, and analyzing data has been described in previous publications.⁸ The study follows the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) recommendations.⁹ The present study is based on deidentified publicly available information, and no Institutional Review Board approval was required. The study conforms to the Declaration of Helsinki.

The database was queried for information on incidence (per 100,000 people) of DALYs and YLDs of pressure injuries from 1990 to 2017 for each state separately; in the US overall; in countries with low, middle, or high sociodemographic index (SDI), for males, and females of all ages. An associated 95% uncertainty interval (UI) for each value was also abstracted.

Statistical Analysis

Descriptive statistics were used to evaluate relative differences in rates of incidence and score of DALYs and YLDs from 1990 to 2017 in the US overall and in each state separately. Similar statistics were used to analyze differences in rates and score for male versus female patients and patients among various age groups. The most current rates and scores in the US were compared with relevant values for countries with low, middle, and high SDI. Rate ratio function in R statistical language was used.¹⁰ Statistical comparisons were made between the values in 1990 and 2017 using t tests performed in STATA (v.13.0; SataCorp).

Incidence

A decrease that was not statistically significant was observed during the studied period for the diagnosis of pressure injury (Table 1). A subgroup analysis based on the age showed that the crude incidence increased with age. Only for the subgroup of patients 95+ years was the decrease in incidence statistically significant (Figure 1, Table 1).  A sex subgroup analysis revealed no statistically significant differences among males and females (Figure 2, Table 2). In reference to geographic differences, Louisiana had the highest incidence (139.3 per 100,000) and Vermont (84.7 per 100,000) the lowest in the US. Statistically significant decreased incidences were observed only in the District of Columbia and Georgia from 1990 to 2017 (Figure 3, Table 3). Our comparison of the USA to other counties showed that in 2017, the US had higher incidence rate than the average high-SDI countries. No statistically significantly changes were observed over time (Figure 4, Table 4).

DALYs

Our analysis on DALYs showed an average decrease in the disability related to the disease in the US; however, this change was not statistically significant for any of the age groups examined (Figure 5, Table 5). A sex subgroup analysis revealed no statistically significant differences among male and female patients (Figure 6, Table 6).  Our geographic analysis identified that all states achieved a relative decrease in the DALYs associated with the disease; however, no differences reached the level of statistical significance (Figure 7, Table 7). No statistically significant differences were observed over time among the US and other countries based on the SDI level (Figure 8, Table 8).

Pressure injury continues to weigh heavily on healthcare systems on a global scale. In the United States alone, previous reports suggested 2.5 million patients per year develop pressure injuries in acute care facilities,¹¹ and the National Pressure Ulcer Advisory Panel estimates an annual cost to the healthcare system to be $3.6 billion.¹² Recent work by Padula et al has elucidated these trends and their relation to healthcare policy, national cost, and Centers for Medicare & Medicaid Services (CMS) reimbursement.¹³ They estimate that each HAPI episode could cost over $10,000 per patient on average, equating to an annual national cost as high as $26.8 billion. Even more alarming is the analysis of the Vizient Clinical Data Base and Resource Manager, which showed a 29.4% increase in the rate of pressure injuries in academic medical centers just between 2015 and 2016.¹⁴

Using the GBD 2017 data, this study highlights that the average incidence and burden of disease remain high in levels similar to those in 1990, with no significant improvement over time. In addition, our comparison with other countries identified that the US continues to have higher incidence rates in comparison to other high-SDI counties.

This brings up the inevitable question: Why is the US behind other countries worldwide in this arena? Multiple key events have occurred in the US over the included time period of this study and can likely be implicated.  In 1992, the Agency for Healthcare Research and Quality (AHRQ) developed pressure injury prevention standards, which have continued to be modified. These modified standards resulted in an initial decrease in incidence. Then, in 2008, the CMS reduced payments for HAPI via the Inpatient Prospective Payment System.¹⁵ To further promote quality of care, the CMS started implementing a 1% penalty of total reimbursements if hospitals fell into the bottom quartile with respect to hospital-acquired conditions (HACs). This was part of the 2015 implementation of the Patient Safety Indicator (PSI) 90 system. In this system, pressure ulcers (PSI-03) are among 7 other hospital-acquired conditions including iatrogenic pneumothorax, catheter-related bloodstream infections, postoperative hip fracture, sepsis, venous thromboembolism, wound dehiscence, and accidental puncture or laceration.¹⁶ However, each HAC is assigned a different weight coefficient based on a severity index, similar to that used in calculation of DALYs.  Pressure ulcers are assigned a significantly lower weight in this system compared with other conditions (only 6%). The lower assigned weight could theoretically result in fewer preventive efforts compared with other measures given to catheter-related bloodstream infections or falls if a hospital system’s overarching priority is to perform well on the PSI90.¹³ It is postulated that this penalty scheme that groups all HACs into one score may have inadvertent negative impacts on some individual HACs such as decubitus ulcer. Similar issues may challenge other countries such as the UK that also have pay-for-performance type systems. Whereas national performance has improved, the US continues to lag behind other high-SDI countries, and there is room for further improvement.

Our findings indicate a relative decrease in the disability associated with the disease; however, this difference was not statistically significant. In addition, it was observed that not all states in the US achieved similar changes in DALYs. It is challenging to speculate as to why some states were able to achieve a decrease in DALY while others saw an increase. The answer is multifactorial, as each state has different policies and demographics that will influence the calculation of DALY.  More investigation is warranted.  On a global level, the differences between countries of different SDI level may be attributed to longer life expectancy and improvement in therapies in higher SDI countries, both of which increase the years living with disease (YLD), creating an overall higher burden. Countries with low SDI, on the other hand, have a higher mortality rate due to lack of resources, and this more heavily increases the observed DALYs.

A subgroup analysis showed that incidence as well as DALYs were relatively—though not statistically significantly—increased with age and were more prevalent in male than female patients.  Past studies have identified age as an independent risk factor for the development of decubitus ulcer along with presence of an existing decubitus ulcer, length of hospital stay, dementia, a low Braden Scale score, and peripheral vascular disease.^17-19 However, female sex has historically been identified as a risk factor over male sex.²⁰ In fact, the Waterlow risk assessment scale developed in 1987 allots 2 points for females and 1 point for males, albeit this tool is not frequently used because the sensitivity and specificity is inferior to that of the Braden Scale.²¹ There have been studies aligning with this data analysis in which higher rates of decubitus ulcer were observed in men.  As opposed to gender predilection, it is theorized that there are more complex risk factors at play such as higher rate of spinal cord injury and other comorbid conditions in men.^22-24

One of the greatest challenges in studying the epidemiology of this injury is the nonuniformity of classification systems used in reporting. The traditional system ranges from non-blanching erythema of intact skin (stage I) to an open wound involving underlying muscle, tendon, or bone (stage IV). However, the NPUAP has recently modified the staging system to include 2 new stages: unstageable and deep tissue pressure injury (DTPI).^25,26 Systematic reviews have clearly identified this discrepancy as a challenge in understanding true incidence and prevalence rates as definitions and staging systems continue to evolve. As such, some European studies conducted over similar timeframes have shown variable outcomes. A total prevalence rate in a Turkish hospital setting between 2010 and 2014 was reported as 3.3%,¹⁸ whereas prevalence rates dropped from 19.5 to 17% in an Italian study between 2010 and 2015.²⁷ The meta-analysis by Li et al suggested a global prevalence rate of 12.8% in hospitalized patients.  However, of the 39 studies eligible for meta-analysis, only 16 of them documented the stage of decubitus ulcer.² Another systematic review including studies from 2000 to 2015 by Tubaishat et al estimated the global prevalence to be anywhere from 6 to 18.5%.³ Again, the variability in outcomes was attributed to the difference in methodological quality among studies. It should also be noted that the emergence of the electronic medical record (EMR) within the last decade may show a misleading upward trend in incidence and prevalence. That is to say that the disease was likely underreported prior to the EMR rollout, and we are now seeing more accurate numbers. With the ability to precisely document and code these injuries in our current system, it will be advantageous to understand the trends of each type or stage of ulcer in the future to better direct management and preventive measures.

This study does not suggest that healthcare providers have turned a blind eye to pressure injury prevention. The NPIAP continues to be an integral task force that has been at work for over 30 years, influencing the European Pressure Ulcer Advisory Panel and the Japanese Society of Pressure Ulcers. Both inpatient and ambulatory settings have quality improvement initiatives and prevention programs designed to employ a multidisciplinary approach to this problem. Key components include skin care, pneumatic mattresses, proper nutrition, and repositioning.²⁸ Padula and colleagues evaluated the effectiveness of a prophylactic 5-layer foam sacral dressing to prevent HAPI. Over a 5-year period, a significant stage III/IV or unstageable pressure injury rate reduction was achieved for minimal cost.²⁹ This is particularly important when considering the disproportionate impact that advanced stage decubitus ulcer has on healthcare cost. An Australian cost-of-illness analysis in 2012 to 2013 found that whereas stage III and IV pressure injuries only comprised 12% of all cases in public hospitals, they accounted for 30% of the total cost.³⁰ It is widely accepted that previous pressure ulcer or presence of a pressure ulcer upon admission is an independent risk factor for progression to higher stages. This was corroborated in a systematic review by Coleman et al among other studies.¹⁹ Other studies attempt to compare cost of prevention to cost of treatment, with the expected conclusion that it is far more efficacious to prevent the disease.³¹ Combining these notions, it would be wise to continue to focus efforts on prevention strategies and consider prophylactic foam dressings or other pressure relieving surfaces for all high-risk patients. One such innovation was recently investigated in a clinical trial by Rubin and colleagues in Pittsburgh, PA. They introduce 2 different electronic devices coined pressure ulcer monitoring platforms (PUMP) devices that capture patient repositioning movements with 85% reliability and for a practical cost. The device would theoretically alert the caregiver as needed to promote optimal and more effective repositioning customized to the patient’s needs.³² This kind of forward thinking will allow us to make necessary advancements and seems promising.

The present study is not without limitations, including the cross-sectional nature of the study and the lack of information regarding the number, stage, and location of the ulcers in each patient.

Pressure injuries incidence and burden remain in high levels, and no significant improvement has been achieved the last decades. In addition, incidence in the US continues to be higher than other high-SDI counties, and we should continue to raise awareness for the prevention and treatment of pressure injuries. There is room for improvement on a national performance level, and further research is needed regarding inconsistencies in regional outcomes. New strategies and devices continue to be investigated.

Affiliations: ¹Division of Plastic and Reconstructive Surgery, Department of Surgery, Rush University Medical Center, Chicago, IL; ²University of Illinois in Chicago, Chicago, IL; ³Department of Surgery, Rush University Medical Center, Chicago, IL

Correspondence: Deana S Shenaq, MD; deana_shenaq@rush.edu

Ethics: This study conforms to the Declaration of Helsinki ethical principles for medical research. The study is based on de-identified information and is exempt from IRB.

Disclosures: AH Dorafshar receives indirect research support from De Puy Synthes and royalties from KLS Martin and Elsevier. The authors have no other relevant financial or nonfinancial interests to disclose.