Construct validity of the MNA was calculated, comparing total MNA scores between patients with BMI < 24 and ≥24 kg/m2, between patients with pressure sores or other skin ulcers and those without, and patients with serum albumin < 3.5 and ≥3.5 g/dl (Table 5). There were significant differences between the two BMI groups (P < 0.001), but not between groups categorized according to serum albumin and skin ulcers.