Long-form but not short-form Mini-Nutritional Assessment is appropriate for grading nutritional risk of patients on hemodialysis--a cross-sectional study

Background: Routine screening/assessment of protein-energy status is essential for preventing uremic malnutrition in patients on hemodialysis (HD). A simple, low cost, reliable and non-invasive tool is greatly desired.

Objective: This study aimed to evaluate the appropriateness of using the long-form (LF) and the short-form (SF) Mini Nutritional Assessment (MNA) for grading the risk of protein-energy malnutrition in patients on HD. DESIGN AND SAMPLING: A cross-sectional study with purposive sampling.

Setting: A hospital-managed hemodialysis center.

Participants: 152 adult ambulatory patients on hemodialysis.

Methods: The nutritional status of each patient was graded with MNA-LF and MNA-SF, each in two versions--a normalized-original (content-equivalent) version (by adopting population-specific anthropometric cut-off points) and an alternative version that replaced calf circumference for BMI in the scale. The SGA, serum albumin and serum creatinine served as references. Cross-tabulation test was used to evaluate the consistency of the versions.

Results: MNA-SF versions rated fewer HD subjects malnourished or at risk of malnutrition (32.2% and 24.3% for T1 and T2, respectively) compared to MNA-LF versions (40.8% and 36.2%) or the SGA (47.4%). MNA-SF versions (kappa=0.450 and 0.446) also did not perform as well as MNA-LF versions (kappa=0.734 and 0.666) in predicting the risk of malnutrition in HD patients using the SGA as the reference. MNA-SF also did not perform as well as the MNA-LF using serum albumin or serum creatinine as the reference.

Conclusions: The MNA-LF is appropriate for predicting protein-energy malnutrition in HD patients but MNA-SF may under-rate these patients. Effort should be made to improve the MNA-SF for HD patients since the short-form is more time-efficient and thus, greatly desired in clinical practice.