Malnutrition prevalence in a medical assessment and planning unit and its association with hospital readmission
Authors: Ulltang Marte , Vivanti Angela P. , Murray Eryn 
Published: October 2013

Objective
To investigate malnutrition prevalence on presentation to a Medical Assessment and Planning Unit (MAPU) in a setting designed to prevent hospital admission, the association of nutritional status with hospital readmission at 90 days, and agreement of nutritional risk between the Malnutrition Screening Tool (MST) and Subjective Global Assessment (SGA).

Methods
Prospective longitudinal cohort study of consecutive patients admitted to MAPU during the first 6 weeks of operation. The main outcome measures were prevalence of malnutrition and hospital readmission at 90 days. Sensitivity and specificity of the MST was assessed against the criterion standard of SGA.

Results
The mean participant age was 62 years (n = 153, s.d. 17.4 years) with 50% male (77/153, 95% CI 42–58%). According to the SGA, 17% (95% CI 8–26%) were assessed as malnourished on admission. The MST identified that 18% (95% CI 12–24%) were at nutritional risk, and participants screening positive for nutritional risk had significantly increased odds of hospital readmission at 90 days (OR 3.4, 95% CI, 1.3–9.1, P < 0.029). The MST was practical and successfully identified patients assessed as malnourished within the MAPU setting (sensitivity 73%, specificity 76%, negative predictive value 93%, positive predictive value 38%).

Conclusions
Malnutrition is a significant problem in a MAPU setting, and patients screened at nutritional risk are at significantly higher risk of hospital readmission within 90 days.

What is known about the topic?
The prevalence of malnutrition in Australian hospitals is estimated to be between 30 and 53%. It is important to identify malnutrition, given that the consequences contribute to increased morbidity, mortality, length of hospital stay, readmission and healthcare costs. Malnutrition screening is strongly advocated as the first step to routinely identify nutritional problems early in acute care settings. To date only one Australian study has documented the prevalence of malnutrition in an acute medical unit setting, estimating it to be 53%.

What does this paper add?
The acute medical unit in the previous study operates under a different model of care acute assessment unit, in which patients are triaged to the wards, and no known study to date has investigated the prevalence of malnutrition in a MAPU setting aiming to avoid hospital admissions. Furthermore, no other studies have explored malnutrition and its association with risk of hospital readmission in these settings. Our study reveals that malnutrition is a problem in MAPU settings, demonstrating the important role malnutrition screening plays in identifying malnutrition risk in a MAPU setting due to the increased risk of readmission at 90 days evident in this group.

What are the implications for practitioners?
The study identified that malnutrition risk significantly increased the odds of hospital readmission at 90 days. The MST was confirmed as a practical tool for use in the MAPU setting, showing acceptable sensitivity and specificity. Incorporation of malnutrition screening and timely intervention may increase the overall effectiveness of the MAPU clinic through avoidance of hospital readmission at 90 days.