Improving the accuracy of pressure ulcer risk calculators: some preliminary evidence

Prevalence of pressure injury among Chinese community-dwelling older people and its risk factors: A national survey based on Chinese Longitudinal Healthy Longevity Survey

AIM

To investigate the distribution of pressure injuries among older adults in China and to identify the associated risk factors.

DESIGN

Cross-sectional study.

METHODS

The identified subjects were collected from 2012 wave of a national Chinese Longitudinal Healthy Longevity Survey. Older people were defined as being 65 years of age or older. We used chi-square test and binary logistic regression to investigate the risk factors of pressure injury development.

RESULTS

A total of 55 older people were documented as suffering from pressure injuries among 6,961 older Chinese adults, with a prevalence of 0.8%. In the group of disability, the prevalence of pressure injuries from high to low was 3.6% in the highly limited group, 0.4% in the moderately limited group, and 0.3% in the not limited group. The prevalence of pressure injury among older people with stroke, cancer, and dementia were 2%, 4.2%, and 6.6%, respectively. According to the final binary logistic regression analysis, age, disability, incontinence, cancer, and dementia emerged as important risk factors for pressure injury development.

CONCLUSION

Pressure injury among Chinese community-dwelling aged people was shown to be associated with age, disability, incontinence, cancer, and dementia. As the development of pressure injury may distinctly increase the burden on individuals and healthcare systems, the social and related institutions should actively prevent and control the disease.

IMPACT

The results of this study will improve the identification of pressure injury among older Chinese people and contribute to the development of effective pressure injury risk management interventions.

Evaluation of the Validity and Reliability of the Waterlow Pressure Ulcer Risk Assessment Scale

Introduction

Prevention is the ideal strategy to tackle the problem of pressure ulcers. Pressure ulcer risk assessment scales are one of the most pivotal measures applied to tackle the problem, much criticisms has been developed regarding the validity and reliability of these scales.

Objective

To investigate the validity and reliability of the Waterlow pressure ulcer risk assessment scale.

Method

The methodology used is a narrative literature review, the bibliography was reviewed through Cinahl, Pubmed, EBSCO, Medline and Google scholar, 26 scientific articles where identified. The articles where chosen due to their direct correlation with the objective under study and their scientific relevance.

Results

The construct and face validity of the Waterlow appears adequate, but with regards to content validity changes in the category age and gender can be beneficial. The concurrent validity cannot be assessed. The predictive validity of the Waterlow is characterized by high specificity and low sensitivity. The inter-rater reliability has been demonstrated to be inadequate, this may be due to lack of clear definitions within the categories and differentiating level of knowledge between the users.

Conclusion

Due to the limitations presented regarding the validity and reliability of the Waterlow pressure ulcer risk assessment scale, the scale should be used in conjunction with clinical assessment to provide optimum results.

Investigating the reliability and validity of the waterlow risk assessment scale: a literature review

The aim of this review was to examine health literature on the reliability and validity of the Waterlow pressure sore assessment scale. A systematic review of published studies relating to the topic was conducted and literature was examined for its relevancy to the topic under investigation. Findings suggest that despite the availability of over 40 assessment tools, the Waterlow assessment scale is the most frequently used by health care staff. Research suggests that the Waterlow Scale is an unreliable method of assessing individuals at risk of pressure sore development with all studies indicating a poor interrater reliability status. Its validity has also been criticized because of its high-sensitivity but low-specificity levels.

Diagnostic accuracy of two pressure ulcer risk scales and a generic nursing assessment tool. A psychometric comparison

AIM

Comparison of the diagnostic accuracy of two pressure ulcer risk assessment scales and one generic nursing assessment tool.

BACKGROUND

Guidelines for pressure ulcer prevention recommend an initial risk screening of all patients, followed by appropriate nursing interventions. Additionally, personal and financial resources have to be allocated carefully to avoid excessive or too little treatment. Risk assessments should be accurate and applicable, and some studies showed that generic nursing tools also provide specific information for nursing diagnoses, like risk for pressure ulcer.

DESIGN

Cross sectional observational study.

METHODS

A total of 1053 adult patients of a university hospital in Germany were investigated. For each patient, the Braden Scale, the Waterlow Scale and the Care Dependency Scale were completed. A skin inspection was conducted by trained nurses. Correlations between the three scales and the mean values of each pressure ulcer risk assessment scales for each Care Dependency Scale value were calculated. To determine the association between susceptibility to pressure ulcer and observed pressure ulcer, the area under the curve was calculated.

RESULTS

There was a higher correlation between the Braden Scale and the Care Dependency Scale (r = 0.82) than between the two pressure ulcer risk assessment scales (-0.65). The highest area under the curve was reached by the Braden Scale (0.86), followed by the Care Dependency Scale (0.83) and the Waterlow Scale (0.81). Only the Braden Scale (cut-off 18) and the Care Dependency Scale (cut-off 65) reached the psychometric requirements of at least 70% sensitivity and 70% specificity.

CONCLUSIONS

The Care Dependency Scale could be used for both a general nursing assessment and as a screening tool for risk for pressure ulcers. The Braden Scale showed the highest association with the occurrence of pressure ulcer.

RELEVANCE TO CLINICAL PRACTICE

The Care Dependency Scale is a useful screening tool to identify patients at risk for pressure ulcers. Nursing assessment activities might be reduced by using a generic nursing assessment tool also for specific risk screening.

Incidence of pressure ulcers in intensive care unit patients at risk according to the Waterlow scale and factors influencing the development of pressure ulcers

AIMS

To determine incidence of pressure ulcers in patients at risk according to the Waterlow scale in intensive care units and to evaluate the effects of risk factors in critically ill patients.

BACKGROUND

Pressure ulcers continue to be an important health problem that increases the risk of illness and death, extends patients' length of hospital stay and increases healthcare expenses.

DESIGN

The study was conducted as a descriptive and prospective study.

METHOD

The sample consisted of 140 patients. Data were collected using a data collection form, the skin assessment instrument and the Waterlow scale.

RESULTS

The incidence of pressure ulcers in intensive care unit patients was found to be 14.3%. The majority of pressure ulcers (74%) were grade I. The mean length of time for pressure ulcer development was found to be 10.4 (SD 1.85) days. A statistically significant difference was found in the patients for pressure ulcer development according to their level of consciousness, activity, cooperation, length of stay, Waterlow scale score and C-reactive protein level. In the multiple stepwise logistic regression analysis, the most influential factors for pressure ulcer development were determined to be length of stay and activity level.

CONCLUSIONS

Extra care needs to be taken to prevent pressure ulcer development in intensive care unit patients who have an extended length of stay, are dependent for activities, have high Waterlow scores, are unconscious and are not cooperative.

RELEVANCE TO CLINICAL PRACTICE

This study determined the incidence of and factors that can affect the development of pressure ulcers in intensive care unit patients who are in a high risk group for the development of pressure ulcers and presented the importance of having Turkish nurses implement interventions directed at these factors.

A design of bioimpedance spectrometer for early detection of pressure ulcer

Prevention of pressure ulcer (PU) has been hampered for a long time by limitations of present risk assessment methodologies for carers. This paper introduces a novel solution of a portable bioimpedance spectrometer (BIS), which is designed to detect in vivo subtle changes in electrical properties of tissues at the portentous onset of PU and thereby establish a reliable assessment method for early detection of PU. The principle of the modified tetrapolar method applied in BIS and system designing methodology are explained thoroughly in this paper. The BIS system can measure complex impedance of human tissues over a wide range of frequencies from 10Hz to 1MHz based on direct digital synthesis (DDS) technique. Different from conventional bioimpedance measuring systems based on phase sensitive detection, the new BIS system shows its integrity in theoretical analysis and simplicity in practical implementation. As an objective, fast, straightforward, and inexpensive technique that captures fundamentally different information than subjective assessment and optical judgment, the new BIS may bring to clinical use for risk assessment of PU in the future.

Using the discrete choice experimental design to investigate decision-making about pressure ulcer prevention by community nurses

This study investigates the preferences of senior community nurses who work as district nurse team leaders in selecting preventive care plans for elderly people at high risk of pressure ulcer formation. The discrete choice experiment (DCE) technique was used. Focus group work produced the following five attributes of nurse decision-making: 'ease of care plan management', 'impact of care plan on patient's lifestyle', 'speed of obtaining the equipment', 'affordability', 'evidence-based practice'. These were incorporated into a self-administered questionnaire, posted to 102 nurses from two integrated acute/community NHS Trusts in Wales. A response rate of 55% was achieved. Respondents were asked to rate the importance of the selected attributes on a 5-point scale. They rated 'evidence-based practice', 'impact of care plan on patient's lifestyle', 'ease of care plan management' and 'speed of obtaining the equipment' highly, whereas 'affordability' was of less importance. However, regression analysis, which is part of the DCE technique, produced a somewhat different picture, with 'impact' being least and 'affordability' most statistically significant. The reasons for this apparent anomaly are discussed and the paper concludes that the DCE approach is capable of yielding important information, which is not produced by simple rating exercises. Such information is potentially of value in the context of modernisation and service configuration.

Portable gage for pressure ulcer detection

Pressure ulcers are widely considered to be a critical problem in rehabilitation since they result in severe discomfort and high healthcare cost. The prevention of pressure ulcers is a constant preoccupation for every nursing team. This paper introduces a novel handheld instrument that can detect subtle changes in the skin biomechanical properties by measuring its biomechanical response. This could be used to detect stage-I pressure ulcers and deep tissue injury. Its high bandwidth makes it possible to load the skin under wide range of conditions. The instrument is portable, inexpensive, and intrinsically precise. Several experiments were conducted to validate the function of the device. Preliminary results show that the device could effectively measure the difference in the viscoelasticity between human skin of different sites, hence paving the way for the development of clinical protocols and trials.

Risk assessment scales for pressure ulcers: A methodological review

Much is written about risk-assessment scales (RASs) for pressure ulcers (PU) and their properties demonstrating that they are of limited value. Less is known about the reasons for these limitations and the scope for improvement. This review examines issues such as structure and scoring for the Norton, Waterlow and Braden scales, showing that the equal-weighting technique behind the current RASs is too simplistic and leads to limitations. It concludes that properly trained, experienced nurses should conduct PU risk assessments, whilst more robust data-driven RASs should be developed using the differential weighting scoring method together with advanced statistical techniques.

Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers: PRESSURE (pressure relieving support surfaces) trial

OBJECTIVE

To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability.

DESIGN

Pragmatic, open, multicentre, randomised controlled trial.

SETTING

11 hospitals in six NHS trusts.

PARTICIPANTS

1972 people admitted to hospital as acute or elective patients.

INTERVENTIONS

Participants were randomised to an alternating pressure mattress (n = 982) or an alternating pressure overlay (n = 990).

MAIN OUTCOME MEASURES

The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability.

RESULTS

Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval--2.3% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02).

CONCLUSION

No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer.

TRIAL REGISTRATION

ISRCTN 78646179.

Complications of adapting pressure ulcer risk assessment scales

This article challenges recommendations to adapt a pressure ulcer risk assessment scale (RAS) according to the clinical context. The transformation of the Cubbin and Jackson (1991) RAS is used to illustrate problems in scale development. When new factors are added to an existing scale, this can lead to unnecessary complexity. When words are changed by a person developing a scale this illustrates their differing beliefs and value judgements. Arbitrary scores for factors are misleading and in some cases mystifying, yet appear to be objective. This article suggests that the relationship between sub-scales and the whole scale have not been adequately accounted for -- they can't simply be added up arithmetically. The paradox of risk is debated, namely, that the more something is thought to be a risk, the less risky it becomes. RASs should be replaced by risk reduction scales linking a risk factor with its outcome following intervention.

Úlceras por presión en cuidados intensivos: valoración del riesgo y medidas de prevención

Pressure ulcers (PU) are associated to greater patient morbidity and mortality. Thus, all prevention measures are very important. In order to establish the appropriate care early, the first measure is the identification of patients at risk of developing PU, using specific scales.

OBJECTIVES

1) to assess the risk of developing PU in the patients admitted in an Intensive Care Unit (ICU), using the Waterlow scale; 2) to identify patients with PU and to analyse the possible relationship between them and the measured risk; 3) to analyse the preventive care received by patients for its prevention.

METHOD

This descriptive study analysed the risk of developing PU in 91 critical patients with a stay greater than 3 days. To measure the risk the Waterlow scale (modified by Weststrate in 1998), that included 14 risk factors, was used. Sociodemographic data, cause of admission, patients with PU, its location and grade and care applied were also collected.

RESULTS

Risk grade obtained on the Waterlow scale was: without risk (< 10 points) in 8 patients, 23 with risk (10-14 points), 29 with high risk (15-19 points) and 31 had very high risk (20 points). Thirteen patients had ulcer, in 10 of them it was present on admission. Their score obtained on the scale was risk in 2 patients, high risk in 5 and very high risk in the remaining 6. A statistically significant difference was found between the mean score of risk of the 13 patients who had ulcer and the remaining sample (21.85-16.83; p = 0.005). When the risk factors included in the scale and its relationship with the presence of ulcer were analysed, statistically significant difference was only found in the "heart failure" factor (vasoconstrictor treatment), p = 0.045. No association was found between age, gender, diagnosis and presence of ulcer. Regarding the daily care applied to patients, the following results were obtained: skin hydration and hygiene were done in 100% of the patients, patient repositioning were done every 2 hours or more frequently in 80% of the patients, every 3 hours in 10% and in the remaining 10%, with a frequency greater than 4 hours. Heel protection was applied in 57% of the patients and special mattress was used in 54%.

CONCLUSIONS

Most of the studied patients had high risk of developing PU. The patients who had an ulcer were at risk of developing it. The low incidence of ulcers obtained in this study allows us to consider appropriate the protocol of care.

An evaluation of the Waterlow pressure ulcer risk-assessment tool

The National Institute for Clinical Excellence (NICE, 2001) stated that in order to achieve clinical governance strategies, risk management in the form of pressure ulcer risk assessment will contribute to improved quality of patient care. Risk-assessment tools must display high-predictive values, be highly sensitive and specific, reliable, and easy and convenient to use. Despite their extensively documented poor performance, pressure ulcer risk-assessment scales play a primary role in the prevention and management of pressure ulcers. The tools attempt to determine patients' risk status by quantifying a range of the most commonly recognized risk factors. Although there are over 40 different assessment tools, the Waterlow pressure ulcer risk-assessment tool is the tool that is most widely used in the UK. This article aims to review studies relating to the reliability, content validity, predictive validity, concurrent validity and the construct validity of the Waterlow pressure ulcer risk-assessment tool.

Incidence and Risk Factors Associated with Pressure Ulcers among Patients with HIV Infection

OBJECTIVE

To assess the incidence of and risk factors for pressure ulcers among patients with advanced human immunodeficiency virus type 1 (HIV-1) infection.

DESIGN

Multicenter trial that included 1258 consecutive patients infected with HIV-1 who had 1815 admissions to 16 acute care infectious disease units in Italy.

METHODS

Data were collected for demographic, clinical, immunologic, and virologic parameters. The chi-square test was used to compare categorical variables, and the Student t test was used for continuous variables. Univariate analysis was performed to examine possible risk factors for pressure ulcers by computing odds ratios; a multiple logistic regression model was used to obtain adjusted estimates of odds ratios while accounting for all possible risk factors.

RESULTS

The incidence of pressure ulcers was 2.31 per 100 admissions, 3.33 per 100 patients, and 1.06 per 1000 patient days. All stages of pressure ulcers were represented in the sample: 7 Stage I (15.9%), 24 Stage II (54.5%), 8 Stage III (18.2%), and 5 Stage IV (11.4%). Multivariate analyses showed that being female, length of hospitalization, and clinical markers of HIV infection were independently associated with pressure ulcers. Mortality rates were 50% among patients with pressure ulcers and 7.2% among patients without pressure ulcers (P <.0001), with an attributable mortality rate of 42.8% and an odds ratio of 12.96 (95% confidence interval 6.99-24.22).

CONCLUSIONS

A higher incidence of pressure ulcers was found in patients infected with HIV-1 when compared with noninfected patients. Because a longer hospitalization may increase the risk of developing a pressure ulcer, practitioners should be aware of the clinical conditions that may prolong a patient's hospital stay. Aggressive preventive strategies should be implemented to decrease the complications associated with pressure ulcers among patients infected with HIV-1.

Pressure ulcer risk assessment: application of logistic analysis

AIM

The aim of this study was to investigate the relative importance of key factors affecting the likelihood of hospital acquired pressure ulcers, thus offering the groundwork for the development of an empirically-based risk assessment scale. It also evaluated the predictive performance of the underlying empirical model and compared its classification ability with the empirically observed ability of the Waterlow risk assessment scale.

BACKGROUND

Pressure ulcers impose a significant burden on patients and carers and demand substantial resources from the health care system. There is, however, a lack of systematic empirical research on which to base the development of risk assessment measurement tools.

METHODS

Multivariate statistical methods were applied to data derived from the records of a cross-sectional sample of around 500 randomly selected inpatient episodes drawn from the population of admissions to a single unit in a large acute hospital during a 2-year period (October 1996 to September 1998). Double-checking of a randomly selected 25% sample of the original records and careful screening out of records with incomplete information or inconsistent values was carried out to ensure a high quality sample. Logit analysis was used to investigate the relative contribution of risk factors, such as continence, skin condition, mobility and inter-hospital transfer to the risk of hospital-acquired pressure ulcer occurrence, whilst cross-validation techniques were employed to check the predictive performance of the model.

RESULTS

The results suggest that a simplified version of the Waterlow risk assessment tool has satisfactory predictive ability and the potential for further development.

CONCLUSIONS

Two main conclusions emerged from this study. First, it is both feasible and worthwhile to pursue improvement in the development of risk assessment tools using statistical methods. Second, locally-determined risk factors will need to be incorporated into the construction of future risk assessment scales.

Measuring the quality of judgement and decision-making in nursing

AIM

This paper discusses measurement of the quality of judgement and decision-making in nursing research. It examines theoretical and research issues surrounding how to measure judgement accuracy as a component of evaluating decision-making in nursing practice.

DISCUSSION

Judgement accuracy is discussed with reference to different methods of measurement, including comparing judgements with independent criteria and inter-judge approaches. Existing research on how judgement accuracy has been measured in nursing practice is examined. Evaluation of decisions is then discussed, including consideration of the process of decision-making and evaluating decision outcomes. Finally, existing research on decision-making in nursing is assessed and the strengths and limitations of different types of measurement discussed.

CONCLUSION

We suggests that researchers examining the quality of judgement and decision-making in nursing need to be aware of both the strengths and limitations of existing methods of measurement. We also suggest that researchers need to use a number of different methods, including normative approaches such as Bayes' Theorem and Subjective Expected Utility Theory.