Assessing the Concurrent Validity and Interrater Reliability of Patient-Led Screening Using the Malnutrition Screening Tool in the Ambulatory Cancer Care Outpatient Setting

Abstract

BackgroundThe prevalence of malnutrition in cancer patients is reported as high as 65%; however, malnutrition screening is often substandard. The Malnutrition Screening Tool (MST) has been validated for use by health care professionals to detect at-risk patients; however, there is a gap in the literature regarding validation of patient-led MST screening. ObjectiveThe aim of the study was to assess the concurrent validity of patient-led MST against the Subjective Global Assessment (SGA) and the interrater reliability of patient-led MST against dietitian-led MST in patients attending ambulatory cancer care services for chemotherapy or supportive treatments. Design/participantsA single-site diagnostic accuracy study of 201 patients between May and June 2017 attending the ambulatory cancer care setting at an Australian metropolitan tertiary hospital in Queensland. Main outcome measurementsThe primary outcome measures were concurrent validity and interrater reliability of MST scores as determined by patients (patient-MST), dietitians (dietitian-MST), and SGA as completed by the dietitian. Statistical analysisConcurrent validity of patient-led MST scores against the SGA was determined using specificity, sensitivity, positive predictive values, and negative predictive values. Interrater reliability of patient-MST and dietitian-MST was assessed using κ coefficient. ResultsThe ability of the patient-led MST scores (0 to 1 vs 2 to 5) to indicate nutrition status was found to have a sensitivity of 94% (95% CI 81% to 99%), a specificity of 86% (95% CI 79% to 91%), and an area under the receiver operating characteristic curve of 0.93 (95% CI 0.89 to 0.96). The positive predictive value was 59% (95% CI 45% to 71%), and the negative predictive value was 99% (95% CI 95% to 100%). A weighted κ of 0.83 (95% CI 0.82 to 0.87) between patient-MST and dietitian-MST was found. ConclusionPatient-led MST screening is a reliable and valid measure that can accurately identify ambulatory cancer care patients as at risk or not at risk of malnutrition.