Abstract
Background: Malnutrition can affect almost every system in the body, and therefore is important to treat properly when present. Despite this, malnutrition is under-diagnosed and hence under-treated in many settings where vulnerable populations exist, including acute hospital care. There is also a tendency for health professionals to presume that individuals with a larger Body Mass Index (BMI) cannot be malnourished.
Objective: To investigate malnutrition screening practices and any differences in the diagnosis and treatment of malnutrition among BMI categories, in two South Island hospitals.
Design: This was a two phase, cross-sectional, observational study at Dunedin and Christchurch hospitals (four wards per hospital). Data was collected over an eight-week period from February to April of 2021. Phase one was an audit of patient medical notes for completion of the Malnutrition Screening Tool (MST) by nurses (in the medical and surgical wards), including rate of completion and accuracy of completion. In phase one, patients who had been admitted to hospital within 48 hours were identified as the participants. In phase two, participants identified as at risk of malnutrition and who provided informed consent had a malnutrition-focused nutritional assessment completed. This included: Subjective Global assessment (SGA), 24-hour food intake recall, Bio-electrical impedance analyser (BIA) data, triceps skinfold, mid-upper arm circumference, handgrip strength (HGS), dietetic referral and intervention, length of stay (LOS), nutrition planning post-discharge (if applicable), documentation of malnutrition. Participants were contacted by phone 30 days post-discharge, to assess weight and/or appetite changes, any continued nutrition support at home, and any hospital readmissions.
Results: In total, student dietitians audited MST completion in 366 inpatients. At Dunedin hospital, nurses completed an MST 9.5% of the time (21 out of 220 patients), compared with 100% for 146 newly admitted patients at Christchurch hospital. Overall, 81 out of 366 (22.1%) patients screened by student dietitians were at risk of malnutrition, and 91.2% (31 out of 34) of phase two participants (all at risk of malnutrition) were later confirmed to be malnourished, of which, 11 (35.5%) had a BMI >30kg/m2. Dietitian referrals were made for 71.4% of underweight participants at risk of malnutrition, but only for 7.7% of overweight and obese participants. The median length of stay overall was 2.2 days, however neither length of stay nor total food intake had any apparent differences between BMI categories, albeit not statistically tested.
Conclusion: MST screening rates were poor at Dunedin Hospital, which may be leading to sub-optimal treatment for those at risk of malnutrition. There is a relatively high rate of patients admitted to hospital wards already at risk of malnutrition, at over 22%, so it is important to try and increase these screening rates. Patients with overweight or obese BMIs tend to be referred to dietitians less frequently and hence are likely also diagnosed with malnutrition less frequently than those who are underweight. They also receive dietetic intervention such as High Energy High Protein (HEHP) diets and Oral Nutrition Support (ONS) less frequently. This suggests that education for health professionals regarding treatment of larger bodied patients may be warranted.