Background: Standard body mass index cut-off points for malnutrition are routinely used for adults independently of their age. The hypothesis of this study was that a cut-off point higher than the usual for the diagnosis of malnutrition might be more precise to access the nutritional risk of aged surgical patients.
Aim: To evaluate the morbimortality in aged surgical patients and its association with nutritional status assessed by body mass index using either the standard and a higher cut-off point for malnutrition.
Patients and methods: All patients admitted for operative procedures (n = 1,912) were allocated to either two groups: <65 years (n = 1,627) or >65 years old (n = 285). The body mass index was used to access the nutritional status. Two different cut-off points for malnutrition (18.5 or 24 kg/m(2)) were used in the group of older patients. Endpoints of the study were length of stay, morbidity and mortality.
Results: Length of stay was higher in patients over 65 years (6 [1-75] days vs. 4 [1-137] days). Both postoperative complications (37/285; 13.0% vs. 109/1627; 6.7%; OR 2.1; IC95% 1.40-3.09) and deaths (15/285; 5.3% vs. 34/1627; 2.1%; OR 2.6; IC95% 1.40-4.84) were most common in the older group. Using a higher cut-off (24 kg/m(2)), the length of stay (8 [1-75] days vs. 4 [1-43] days), postoperative complications (28/152; 18.4% versus 9/133; 6.8%; OR 3,1; IC95% 1.41-6.86) and re-operations (16/152; 10.5% versus 3/133; 2.2%; OR 5.1; IC95% 1.45-17.91) were greater in malnourished patients. However these correlations were not statistically significant with the cut-off point for malnutrition in 18.5 kg/m(2).
Conclusions: Morbimortality is higher in surgical patients over 65 years old. In these, the cut-off point set in 24 kg/m(2) was most associated with the occurrence of postoperative complications, re-operations and length of stay.