Sixteen years trends in reported undernutrition.

BACKGROUND & AIMS: How undernutrition is reported in hospital discharge data is not understood. To assess trends in reported undernutrition and its management among hospitalized patients in Switzerland, and the association between reported undernutrition and in-hospital mortality, acquired infection, intensive care unit stay (ICU), and length of hospital stay (LOS).

METHODS: Data from the Swiss hospital discharge databases from 1998 to 2014 (n = 13,297,188 hospitalizations, 52.2% women, 48.4% aged 65+, and 85% Swiss national). Reported undernutrition was defined by the presence of any undernutrition-related International Classification of Diseases 10th revision code. Nutritional management was defined by the presence of any nutritional intervention code.

RESULTS: Prevalence of reported undernutrition increased from 0.32% in 1998 to 3.97% in 2014 in Switzerland, and similar but varying trends were found for each of the seven Swiss administrative regions: ranging from 0.18% to 2.13% in Ticino and from 0.23% to 5.63% in Mittelland. Undernutrition management of hospitalizations with reported undernutrition increased from 0.6% in 1998 to 57.8% in 2014, with wide variations according to administrative region: from 0% to 32.9% in Ticino and from 0% to 68.9% in Central Switzerland. After multivariable adjustment, reported undernutrition was positively associated with in-hospital mortality: odds-ratio and (95% confidence interval): 2.30 (2.26-2.34); acquired infection: 3.57 (3.46-3.70); ICU stay: 1.65 (1.63-1.68) and longer LOS: 19.6 ± 0.2 vs. 13.0 ± 0.1 days.

CONCLUSION: Undernutrition is increasingly reported in Switzerland; still, over 40% of undernourished hospitalizations don't benefit from nutritional support. Reported undernutrition is associated with increased in-hospital mortality, acquired infection, ICU stay, and LOS.