Claudia Gorecki

Impact of Pressure Ulcers on Quality of Life in Older Patients: A Systematic Review

OBJECTIVES: To identify the impact of pressure ulcers (PUs) and PU interventions on health‐related quality of life (HRQL).

Patient risk factors for pressure ulcer development: Systematic review

OBJECTIVE To identify risk factors independently predictive of pressure ulcer development in adult patient populations? DESIGN A systematic review of primary research was undertaken, based upon methods recommended for effectiveness questions but adapted to identify observational risk factor studies. DATA SOURCES Fourteen electronic databases were searched, each from inception until March 2010, with hand searching of specialist journals and conference proceedings; contact with experts and a citation search. There was no language restriction. REVIEW METHODS Abstracts were screened, reviewed against the eligibility criteria, data extracted and quality appraised by at least one reviewer and checked by a second. Where necessary, statistical review was undertaken. We developed an assessment framework and quality classification based upon guidelines for assessing quality and methodological considerations in the analysis, meta-analysis and publication of observational studies. Studies were classified as high, moderate, low and very low quality. Risk factors were categorised into risk factor domains and sub-domains. Evidence tables were generated and a summary narrative synthesis by sub-domain and domain was undertaken. RESULTS Of 5462 abstracts retrieved, 365 were identified as potentially eligible and 54 fulfilled the eligibility criteria. The 54 studies included 34,449 patients and acute and community patient populations. Seventeen studies were classified as high or moderate quality, whilst 37 studies (68.5%) had inadequate numbers of pressure ulcers and other methodological limitations. Risk factors emerging most frequently as independent predictors of pressure ulcer development included three primary domains of mobility/activity, perfusion (including diabetes) and skin/pressure ulcer status. Skin moisture, age, haematological measures, nutrition and general health status are also important, but did not emerge as frequently as the three main domains. Body temperature and immunity may be important but require further confirmatory research. There is limited evidence that either race or gender is important. CONCLUSIONS Overall there is no single factor which can explain pressure ulcer risk, rather a complex interplay of factors which increase the probability of pressure ulcer development. The review highlights the limitations of over-interpretation of results from individual studies and the benefits of reviewing results from a number of studies to develop a more reliable overall assessment of factors which are important in affecting patient susceptibility.

Exposure to internal muscle tissue loads under the ischial tuberosities during sitting is elevated at abnormally high or low body mass indices

Deep tissue injury (DTI) is a severe pressure ulcer characteristic of chairfast or bedfast individuals, such as those with impaired mobility or neurological disorders. A DTI differs from superficial pressure ulcers in that the onset of DTI occurs under intact skin, in skeletal muscle tissue overlying bony prominences, and progression of the wound continues subcutaneously until skin breakdown. Due to the nature of this silently progressing wound, it is highly important to screen potentially susceptible individuals for their risk of developing a DTI. Abnormally low and high values of the body mass index (BMI) have been proposed to be associated with pressure ulcers, but a clear mechanism is lacking. We hypothesize that during sitting, exposure to internal muscle tissue loads under the ischial tuberosities (IT) is elevated at abnormally high or low body mass indices. Our aims in this study were: (a) to develop biomechanical models of the IT region in the buttocks that represent an individual who is gaining or losing weight drastically. (b) To determine changes in internal tissue load measures: principal compression strain, strain energy density (SED), principal compression stress and von Mises stress versus the BMI. (c) To determine percentage volumes of muscle tissue exposed to critical levels of the above load measures, which were defined based on our previous animal and tissue engineered model experiments: strain>or=50%, stress>or=2 kPa, SED>or=0.5 kPa. A set of 21 finite element models, which represented the same individual, but with different BMI values within the normal range, above it and below it, was solved for the outcome measures listed above. The models had the same IT shape, size, distance between the IT, and (non-linear) mechanical properties for all soft tissues, but different thicknesses of gluteus muscles and fat tissue layers, corresponding to the BMI level. The resulted data indicated a trend of progressive increase in internal tissue loading, particularly in volumetric exposure to critical loading for BMI values outside the 17<or=BMI<or=22 kg/m(2) range, supporting our hypothesis for this study. We concluded that exposure to internal muscle tissue loads under the IT during sitting is optimally reduced at the low-normal BMI range, which is important not only in the context of DTI research, but also for understanding general sitting biomechanics.

What influences the impact of pressure ulcers on health-related quality of life? A qualitative patient-focused exploration of contributory factors.

With the recognition of health-related quality of life (HRQL) as an important and relevant outcome in pressure ulceration, it is important to gain better understanding of the complex relationship among the various factors that affect it. A problem with existing literature in this area is that the impact of having a pressure ulcer on HRQL is combined conceptually with contributory factors which may influence outcome. This study identified contributory factors affecting pressure ulcer-related HRQL and explored interrelationships between factors based on views of adults with pressure ulcers. We obtained patient-reported qualitative data through semi-structured interviews with 30 patients with pressure ulcers recruited from hospital and community settings around England and Northern Ireland. Patients described how pressure ulcers affected their lives by recounting specific relevant events. Events (patient-reported issues) were sorted into categories and data framework analysed to produce a taxonomy of contributory factors. Inter-rater reliability established the extent of agreement between two independent raters. We identified 16 contributory factors, into two theme taxonomy: experience-of-care and individual-patient factors, defined by descriptive components. Our taxonomy is a comprehensive theoretical model of factors that contribute to pressure ulcer-related HRQL. We have also identified further research priorities to inform clinical practice.

A systematic review of risk factors for the development and recurrence of pressure ulcers in people with spinal cord injuries

Study design:A systematic review was undertaken, based upon methods recommended for effectiveness questions but adapted to identify observational risk factor (RF) studies.Objectives:The literature identifies many RFs for pressure ulcer (PU) recurrence and development; however, RFs independently predictive of PU development in adults with spinal cord injury (SCI) have not been determined. A systematic review was undertaken to identify RFs for PUs for people with SCI.Setting:Acute hospital, community and rehabilitation settings.Methods:Electronic searches of MEDLINE, EMbase and Cochrane databases from 1980 to 2011 were completed. Retrieved studies were assessed for eligibility and quality criteria applied by two independent reviewers. Identified RFs were categorised into themes and compared and contrasted with RFs identified for the general PU population.Results:The five studies included 18 RFs. These were classified into six themes: sociodemographic, neurological, functional, clinical, biological and medical care management. RFs for both the general and SCI-specific populations were similar, however, clinical, functional and hospital management emerged as specific RF domains for the SCI population.Conclusion:We identified SCI-specific RFs for the development and recurrence of PUs. However, these findings are based on a small number of studies; highlighting the need for further confirmatory work to reduce PU development and recurrence, and provide a foundation for SCI risk assessment development.

Effects of Intramuscular Fat Infiltration, Scarring, and Spasticity on the Risk for Sitting-Acquired Deep Tissue Injury in Spinal Cord Injury Patients

Sitting-acquired deep tissue injury (DTI) is a severe form of pressure ulcer (PU) often affecting patients with spinal cord injury (SCI) who also tend to suffer from intramuscular fat infiltration, soft tissue scarring (due to previous PU), and/or muscle spasticity in their buttocks. We previously used finite element (FE) modeling to evaluate whether abnormal bodyweight is a risk factor for sitting-acquired DTI. Here we hypothesize that fat infiltration, scarring, or spasms increase internal loads in the gluteus muscles in the vicinity of the ischial tuberosities during sitting, which consequently put SCI patients with these conditions at a higher risk for DTI. Our objective was to determine changes in gluteal strains and stresses and tissue volumes exposed to elevated strains/stresses associated with these factors. Thirty-five FE models of coronal slices through the seated buttocks, simulating these conditions at different severities, were developed. We calculated peak strains and stresses in glutei and percentage volumes of muscle tissue exposed to above-critical strains/stresses (compression strain≥50%, compression/von Mises stress≥2 kPa, and strain energy density≥0.5 kPa). Progressive intramuscular fat infiltration increased all the aforementioned outcome measures. Increase in size of scar patterns that were contained in both muscle and fat tissues similarly elevated the outcome measures. Spasms increased muscle stresses and volumetric exposures to stress, but tissue volumes at risk were ∼1-2% and increases due to spasticity were slight. We conclude that the above potential risk factors can be listed according to the following order of importance: (i) fat infiltration, (ii) scars contained in both muscle and fat tissues, and (iii) spasms. This information should be considered when prioritizing prevention means and resources for patients with SCI.

Evaluation of five search strategies in retrieving qualitative patient-reported electronic data on the impact of pressure ulcers on quality of life.

AIM This paper is a report of a study conducted to compare the effectiveness of qualitative methodology search strategies with subject-specific (health-related quality of life) search strategies in the retrieval of qualitative patient-reported data of the impact of pressure ulcers on health-related quality of life. BACKGROUND Methods to locate qualitative patient-reported health-related quality of life research data electronically have undergone little replication and validation. A major problem in searching for this type of data is that it is reported in accounts of both primary qualitative research as well as mixed methods research. DATA SOURCES We combined five search strategies with terms for pressure ulcer and searched seven electronic databases from inception to October 2007. METHODS The sensitivity, specificity, precision and accuracy for each search strategy were assessed. RESULTS A subject-specific (health-related quality of life) search strategy, developed by us, had a high yield (100% sensitivity), but low specificity (<50%). The research methodology-based strategies had lower yields (sensitivity 72-83%) but high specificity (79-83%). Importantly, subject-specific search strategies identified all studies reporting qualitative patient-reported health-related quality of life data, whereas, research methodology-based strategies did not identify qualitative data reported in mixed method studies, making subject-based strategies more effective in retrieving qualitative patient-reported health-related quality of life research. CONCLUSION An important consideration in the health-related quality of life field is that qualitative data are reported in both qualitative and mixed methodology research and searching for this type data involves trade-offs between yield, sensitivity and specificity. Accurate indexing of subject-specific outcomes and methodology used in electronic databases and publications is also needed.

Development and validation of a new patient-reported outcome measure for patients with pressure ulcers: the PU-QOL instrument.

BackgroundPatient-reported outcome (PRO) data are integral to patient care, policy decision making and healthcare delivery. PRO assessment in pressure ulcers is in its infancy, with few studies including PROs as study outcomes. Further, there are no pressure ulcer PRO instruments available.MethodsWe used gold-standard methods to develop and evaluate a new PRO instrument for people with pressure ulcers (the PU-QOL instrument). Firstly a conceptual framework was developed forming the basis of PU-QOL scales. Next an exhaustive item pool was used to produce a draft instrument that was pretested using mixed methods (cognitive interviews and Rasch Measurement Theory). Finally, we undertook psychometric evaluation in two parts. This first part was item reduction, using PU-QOL data from 227 patients. The second part was reliability and validity evaluation of the item-reduced version using both Traditional and Rasch methods, on PU-QOL data from 229 patients.ResultsThe final PU-QOL contains 10 scales for measuring symptoms, physical functioning, psychological well-being and social participation specific to pressure ulcers. It is intended for administration and patients rate the amount of “bother” attributed during the past week on a 3-point response scale. Scale scores are generated by summing items, with lower scores indicating better outcome. The PU-QOL instrument was found to be acceptable, reliable (Cronbach’s alpha values ranging 0.89 - 0.97) and valid (hypothesised correlations between PU-QOL and SF-12 scores (r >0.30) and PU-QOL scales and sociodemographic variables (r <0.30) were consistent with predictions).ConclusionsThe PU-QOL instrument provides a standardised method for assessing PROs, reflecting the domains in a pressure ulcer-specific conceptual framework. It is intended for evaluating patient orientated differences between interventions and in particular the impact from the perspective of patients.

Patient-reported outcome measures for chronic wounds with particular reference to pressure ulcer research: A systematic review

OBJECTIVES Pressure ulcers are a major health problem, affect patient psychological, physical and social functioning, and cause significant treatment burden. For comprehensive assessment of the benefits of an intervention, patient-reported evidence of the impact of an intervention on important patient outcomes should be made. We systematically reviewed the quality of life literature on chronic wounds to determine the suitability of generic and chronic wound-specific outcome measures for use in evaluating patient outcomes in pressure ulcer research. DESIGN A systematic review of the literature. DATA SOURCES Searches of eight electronic databases from inception until May 2012 were undertaken. REVIEW METHODS Quality of life domains, item content and content relevance were determined for identified outcome measures. The content validity of identified measures was assessed against an empirically derived pressure ulcer-specific conceptual framework. RESULTS Three generic and 14 chronic wound measures were identified but no pressure ulcer-specific measures. None of the existing measures cover all quality of life domains important in pressure ulcers. One condition-specific measure, the Venous Leg Ulcer Measure, matched most closely conceptually, but failed to represent three important domains and contained items not specific to pressure ulcers. CONCLUSIONS Currently, outcomes important in pressure ulcers are inadequately covered by generic and chronic wound-specific instruments despite similar conceptual models. Highlighted is the need for clear conceptualisation of content as well as determining appropriateness when selecting outcome measures in the future.

Applying mixed methods to pretest the Pressure Ulcer Quality of Life (PU-QOL) instrument

PurposePretesting is key in the development of patient-reported outcome (PRO) instruments. We describe a mixed-methods approach based on interviews and Rasch measurement methods in the pretesting of the Pressure Ulcer Quality of Life (PU-QOL) instrument.MethodsWe used cognitive interviews to pretest the PU-QOL in 35 patients with pressure ulcers with the view to identifying problematic items, followed by Rasch analysis to examine response options, appropriateness of the item series and biases due to question ordering (item fit). We then compared findings in an interactive and iterative process to identify potential strengths and weaknesses of PU-QOL items, and guide decision-making about further revisions to items and design/layout.ResultsAlthough cognitive interviews largely supported items, they highlighted problems with layout, response options and comprehension. Findings from the Rasch analysis identified problems with response options through reversed thresholds.ConclusionsThe use of a mixed-methods approach in pretesting the PU-QOL instrument proved beneficial for identifying problems with scale layout, response options and framing/wording of items. Rasch measurement methods are a useful addition to standard qualitative pretesting for evaluating strengths and weaknesses of early stage PRO instruments.