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

Abstract

Background: The 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.

Objective: The 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/participants: A 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 measurements: The 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 analysis: Concurrent 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.

Results: The 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.

Conclusion: Patient-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.

Keywords: MST; Malnutrition screening tool; Patient-centered care; Patient-led screening; Validity.