Malnutrition Classification
A total of 353 patients participated with a mean age of 79.6 (SD=7.0) years; 59.2 % (n= 209) of participants were female. Using the MNA-SF screening tool, 7.6% (n=27) older adults attending the ED were categorised as malnourished, 28.0% (n=99) were categorised as at risk of malnutrition and 64.3% (n=227) had a normal nutritional status. Table 2 presents the distribution of the component information of the MNA-SF tool as recorded in the sample of patients.
When asked about the 3 months before ED attendance, weight loss was reported by 15.5% (n=55) older adults with 5.9% (n=21) stating a loss of body weight greater than 3kg in the previous 3 months. A moderate to severe decline in food intake was reported by 20.4% (n=72) older adults. Measured BMI was recorded for 13.0% (n=46) of the 353 patients, with mean BMI of 27.8 (SD=5.7) kg/m2. Among those with a BMI recorded and categorised as overweight and obese (67.4%, n=31), 13% (n=4) were identified as ‘at risk of malnutrition’ with the remainder having normal nutrition status.
Participant characteristics between MNA-SF Categories
Table 3 shows the characteristics of the study participants as lower urgency patients admitted to the ED and the difference in characteristics between MNA-SF categories. There was no difference in the number of participants in the age groups (60-74, 75-84, and 85+ years) between the MNA categories. Results suggest those who were screened as being malnourished had poorer QOL scores (EQ-5D median 15 (IQR 6.0) vs 12 (7) and 11 (6.0), p<0.001; EQ-VAS median 50 (IQR 20) vs 50 (30) and 65 (30), p<0.001), were more frail (Clinical Frailty Score 5.6 (1.1) vs 4.5 (3.7) and 3.7 (1.2), p<0.001), more at risk of adverse health outcomes (ISAR score 3.7 (1.2) vs 2.8 (1.3) and 2.3 (1.2), p<0.001), had poorer functional status (Barthel score 13.0 (9.0) vs 17.0 (6.0) and 18.0 (5), p<0.001), and longer waiting times in the ED (PET 22.6 (11.4) vs 18.1 (17.2) and 17.2 (14.4) hours, p<0.001) compared to older adults who were at risk of malnutrition or had normal nutritional status, respectively. Those who had normal nutrition status were less likely to be discharged home from the ED (20.3% (n=46) vs 40.4% (n=40) and 33.3% (n=9) vs, p<0.001) compared to older adults who were screened at risk of malnutrition or had malnutrition, respectively.
Differences in follow-up outcomes between MNA-SF categories
Table 4 presents the outcomes measured at 30-day follow-up since the index ED visit and differences between MNA-SF categories. In general, those who were malnourished were more likely to have reported a hospital admission (29.6% (n=8) vs 12.1% (n=12) and 10.6% (n=24), p=0.02), a nursing home admission (33.3% (n=9) vs 24.4% (n=24) and 8.4% (n=19), p<0.001), a reduced quality of life (40% (n=10) vs 15.1% (n=13) and 13.3% (n=28), p=0.02) and reduced functional status (52% (n=13) vs 36% (n=31) and 24.8% (n=52), p=0.02), compared to the older adults who were at risk of malnutrition or had normal nutritional status, respectively.
While similar patterns were observed at 6 months, with those categorised as being malnourished most at risk of functional decline, these differences between the MNA SF and 6-month outcomes were not statistically significant (Appendix 1).
Malnutrition status as a predictor of reported decline in Functional Status and Quality of Life
Hierarchical logistic regression models were used to analyse associations between MNA-SF categories of nutritional status and the reported decline in functional status and quality of life at 30-day follow up. Table 5 shows the models of declining functional status and MNA-SF categories controlling for sex, age, quality of life, risk of adverse health outcomes and frailty. The patients who were screened as malnourished in the ED were over three times more likely to have functional decline at follow-up, when compared to the patients who were identified as having a normal nutritional status in the ED (Model 1; unadjusted OR of 3.29 (95% CI = 1.41, 7.66), p=0.008). However, when controlling for sex, age, quality of life, risk of adverse health outcomes and frailty, malnutrition was no longer a significant predictor of functional decline (Model 3; unadjusted OR of 1.53 (95% CI = 0.57, 4.13,) p=0.61).
Table 6 shows the models of reported decline in quality of life at 30-days follow up and MNA-SF categories controlling for sex, age, functional ability, risk of adverse health outcomes and frailty. Patients who were identified as malnourished in the ED, were over four times more likely to report a decline in quality of life when compared to patients who were identified as having a normal nutritional status (Model 1; unadjusted OR of 4.33 (95% CI = 1.77, 10.59), p=0.005). Furthermore, patients are more likely to report a significant decline in quality of life when confounding factors including sex, age, functional status and frailty are accounted for (Model 3; adjusted OR of 3.66 (95% CI = 1.27, 10.56), p=0.02).