Author: Jolene Thomas
Thomas, Jolene, 2020 Under-nutrition in vascular surgery patients: Development of a malnutrition screening tool to identify those at risk, Flinders University, College of Nursing and Health Sciences
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The prevalence of vascular disease and the requirement for vascular surgery services in increasing. Concerning rates of undernutrition and associated poorer outcomes in this patient population are being reported in the literature, hence a comprehensive review of the literature was conducted and is presented in chapter 2. Results of the review showed that undernutrition is prevalent in vascular patients which is linked to poorer outcomes. Micronutrient deficits are prevalent which is of great concern when many have key roles to play in vascular health and wound healing. Identification of undernutrition is a challenge with the literature review highlighting that there are no validated screening tools for vascular surgery patients.
An observational study was conducted with the aims to (1) investigate the prevalence of undernutrition and the impact on patient outcomes in a heterogenous sample of vascular surgery inpatients and (2) to examine the validity of commonly used and researched screening tools in this patient group.
There was a high prevalence of undernutrition in the study sample, in particular micronutrient deficits with >44% of participants having suboptimal zinc, iron, vitamin D or vitamin C status (chapter 4). Overall, 75% were deemed undernourished which was associated with several poorer outcomes on discharge. Four commonly used screening tools (MST, MUST, MNA-SF and NRS-2002) and a nutrition assessment tool (PG-SGA) were not valid in the study sample (chapter 5) which lead to the conclusion that a screening tool specific for vascular surgery patients was warranted.
Exploratory Factor Analysis and k-fold cross validation techniques were utilised to develop a malnutrition screening tool (VMST) specifically for use within the vascular surgery population (chapter 6). The new tool has good sensitivity (87%), fair diagnostic accuracy and consistency which were all improved compared to the tools that were examined. The VMST also has improved discriminant and convergent validity whilst being predictive of a number of discharge outcomes.
Chapter 7 explores the health care costs and clinical outcomes of the study participants at 12-months post discharge, with results showing significant health care spending that varied across the types of vascular disease. Participants deemed ‘at risk’ of malnutrition on the VMST were more likely to have experienced poorer outcomes and have incurred higher costs.
This research is the first to conduct a comprehensive assessment of nutritional status in a heterogenous sample of vascular surgery patients and to examine the validity of malnutrition screening tools in identifying those at risk. The VMST is the first screening tool to be developed using robust methodology that has good validity and predictive ability both at discharge and 12-months. This research is also the first to explore health care costs and whether a malnutrition screening tool can predict higher health care costs. Future research will focus on translation of this research into clinical practice to determine whether the implementation of the screening tool would work in the environment for which it was developed and to determine what conditions or factors impact on whether implementation is successful or unsuccessful.
Keywords: vascular surgery, malnutrition, screening tool, vascular disease
Subject: Surgery thesis
Thesis type: Doctor of Philosophy
Completed: 2020
School: College of Nursing and Health Sciences
Supervisor: Michelle Miller