“A conceptual model is a set of highly abstract, related constructs that broadly explains phenomena of interest, express assumptions, and reflects a philosophical stance” (Burns and Grove, 2001, p.458). The term “conceptual framework” is used in this study because a model instead of theory was used to understand the relationships between different variables.
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In this study, a conceptual framework was developed to explore the association between a number of interventions and PU prevention. It is also intended to explore the association between a number of assumed risk factors and acquiring PUs. The current conceptual framework was based on the literature review findings. Evidence to support effective interventions that prevented PUs in the literature reviewed was unclear. Also, the evidence to support the relationship between certain risk factors and PU was vague, and sometimes contradictory. The lack of a robust methodological design was common in some of the studies reviewed. Likewise, the literature revealed the doubtful effectiveness of RAS. In order to overcome this doubt, the current enquiry employed Waterlow scale in a different manner. Waterlow scale was used here not as a tool for predicting PUs, but primarily to control some of the risk factors that can make a difference in patients’ susceptibility to PUs. Matching two sets of patients who shared a number of Waterlow sub-scores can control a number of these risk factors. Doing this will create a more suitable environment for comparing different interventions, as well as risk factors, between patients who developed PU and those who didn’t.
Different concepts in this study were linked together using the web of causation model. As stated earlier, the web of causation model can reveal which risk and preventive factors were related to the phenomenon of interest (PUs). As a result, using the web of causation model sets the conceptual basis for a sound comparison that can reveal which intervention were associated with prevention and which risk factors were associated with PUs. Moreover, using this model as a theoretical basis for the study may provide clear evidence for both risk factors and interventions, as well as resolving the interaction between different
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variables through using multivariate analysis. The schematic presentation (Figure 2.2) shows the general conceptual approach of this study. In order to explore which interventions were effective and which risk factors were associated with ulceration, two groups of patients were retrospectively chosen. These two groups overlap in the area of Waterlow sub-scores and differ in PU status. Applying this framework facilitates isolating effective intervention and risk factors as they occur in an actual clinical setting. This could give empirical evidence to suggest which interventions were effective. In addition, this framework controls only a number of risk factors (matched Waterlow sub-scores). This means that other factors (in addition to interventions) could vary, and possibly be linked to PUs.
In area of health care, wound care and PUs, matching patients on specific characteristics was also implemented in order to control the effect of certain variable (confounders) on the outcome, consequently having more accurate results. Girou et al (2000) conducted a matched design study to explore the relation between non-invasive ventilation and lowering the risk of hospital acquired pneumonia. This study matched patient on a number of risk factors that are related to pneumonia. In the area of wound care this matched design was also used. Lerman et al (2010) matched two groups of patients on pre-established characterstics that are known to effect wound healing to investigate the efficacy of two wound treatment approaches.
The matched design was also used in the area of PUs. In a retrospective study conducted to identify risk factors of severe PUs, cases and controls were matched on age, gender,
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immobility and cachexia to indentify other risk factors of PUs more accurately (Von Renteln-Kruse et al., 2005).
Figure 2.2: General conceptual approach of this study
2.12 Chapter summary
This chapter reviewed and critiqued previous literature related to PU risk factors and preventive interventions. The purpose of this was to identify any consensus in previous studies regarding the role of a certain risk factor(s) in the development of PUs, or the role of any interventions that can prevent PUs, and to critically analyze and identify shortcomings in the previous literature in order to overcome some of them during the study course, as well as to build on their contributions.
Literature was searched with relevant key words according to a predetermined search strategy. Retrieved studies were evaluated for their relatedness and quality. The main
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themes in the literature review were PU risk factors and preventive interventions. Focusing on these themes was to explore available evidence in the area of the current study.
Reviewing the studies that investigated PU risk factors revealed contradictory and sometimes weak evidence regarding the effect of some risk factors on PUs development. Different studies had different methodological or statistical approaches and investigated different sets of risk factors. Also, different follow-up periods were used, and patients’ medical conditions varied between studies. All of these factors, in addition to the methodological weaknesses found in some studies, make it difficult to draw a conclusion concerning the best factors that can predict PUs.
In the area of preventive interventions, numerous studies were found that investigated different modalities and strategies for prevention, including re-positioning regimens and techniques, support surfaces, heel-protecting devices, referral to physiotherapist, nutritional interventions, referral to a dietician, interventions to prevent incontinence adverse effects, barrier creams and emollients. Making a sound comparison between different studies to reach a conclusion about the best preventive intervention is difficult due to contradicting and weak evidence reported in the literature.
Although the main themes of literature review were PU risk factors and preventive interventions, other areas of research related to these terms were also explored. These included PU prevalence and incidence, RASs for PU, grading systems for PUs and PUs prevention guidelines. Prevalence and incidence studies reported varied figures of these
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rates. Comparisons between these different figures were difficult due to different methodologies and settings of studies reporting these figures.
RASs were also important in this area because they can divide patients into risk groups in order to direct nursing preventive interventions. The most commonly used RASs were Waterlow, Braden and Norton. In order for an RAS to be effective in predicting patients at risk of PUs, it must be valid and reliable. A wide range of these measures were reported in different studies for different scales. This is most probably due to methodological differences among these studies (e.g. using different data collection methods, different settings and different population characteristics). This created some doubt regarding their effectiveness. However, nurses must not ignore using one when offering care for their patients. Formal programmes for prevention needs a formal risk assessment tool to create continuity of care and initiate preventive measures based on specific patient risk factors.
Different grading systems were also explored. In the clinical area there is a need for a robust grading system of PUs in order to indicate PUs presence and degree of severity. This is also reflected in the current study, because through using a grading system patients can be divided as having PUs or not. In general, studies that addressed the reliability of grading systems are few, and they lack consistency, which makes it difficult to compare them. Methodological issues noticed in these studies prevented their generalizability.
In the clinical setting, the desirable attribute of PU guidelines is to effectively prevent the development of new PUs. Studies that examined the clinical effectiveness of these guidelines showed that they improved the outcome in preventing pressure ulcers. However,
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this conflicted with the high incidence and prevalence rates reported in literature. Studies that addressed effectiveness of guidelines did not establish their effectiveness against robust criteria. Also, some of these studies only addressed effectiveness in a certain type of clinical setting.
A general conceptual framework was developed to explore the association between a number of interventions and PU prevention, while exploring the association between a number of risk factors and acquiring PUs. The conceptual model of the study was based on a web of causation epidemiological model, which is concerned with multi-causal
relationships between a medical condition and the number of factors that can contribute to its occurrence or prevention.
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CHAPTER 3 .. Chapter Three: Methodology
3.1
Introduction
This chapter is intended to guide the study’s plan of action. It involves explanation of the methodology used to answer research questions and test study hypotheses. Polit and Hungler (1999, P.707) defined research methods as “the steps, procedures and strategies for gathering and analyzing the data in a research investigation”. These steps used to collect and analyse data represent a scientific method of inquiry. This scientific method is denoted as research. In this concern, research is used to create evidence-based answers to the research questions.
However, for these questions to be answered in a logical and robust manner, an appropriate approach must be followed. This approach must be consistent with the nature of inquiry and data collected. In addition, other aspects of the study are affected due to this approach. These include the data collection method, data analysis and later results interpretation.