Nutritional status in hospitalized patients: prevalence, déterminants and impact on hospital stay, mortality and costs

Undernutrition is a frequent condition among hospitalized patients, leading to increased morbidity, mortality, length of hospital stay, and health costs. However, few studies have reported undernutrition prevalence and its management in Switzerland. Indeed, very little information exists for Switzerland regarding the factors associated with undernutrition and its impact on health outcomes and health costs. This project thus aimed to better characterize the prevalence, determinants, management, and consequences of undernutrition among hospitalized patients in Switzerland. To achieve this, five studies were conducted: one literature review, two cross-sectional studies, one diagnostic accuracy study, and one trend analysis. The initial literature review showed that in Europe, undernutrition represents a considerable economic burden, representing as much as 10% of total national health expenditures. The first cross-sectional study was conducted in the Lausanne university hospital and showed that three out of five hospitalized patients are ‘at-risk’ of undernutrition, but only half of them were nutritionally managed; the study also showed that nutritionally ‘at-risk’ patients had higher in- hospital mortality and costs, while their reimbursement rates were lower. Further, the diagnostic accuracy study showed that, despite a good specificity (87%), undernutrition-related codes in hospital discharge data had low sensitivity (43%) and positive predictive values (28%), thus precluding adequate evaluation of prevalence rates of undernutrition. The second cross-sectional analysis focused on hospital discharge data for whole Switzerland; it showed considerable regional variations regarding the reporting of undernutrition and its management, highlighting the absence of standardized procedures for the whole country. Analysis of hospital discharge data for whole Switzerland for the period 1998-2014 showed a several-fold increase in the prevalence of reported undernutrition-related codes (e.g. from 0.18% to 2.13% in Ticino and from 0.23% to 5.63% in Mittelland). Nevertheless, in 2014, still 40% of hospitalizations with an undernutrition-related code had no indication of nutritional management. Overall, this project provided some important information regarding the prevalence, determinants, and impact of undernutrition in Swiss hospitals. The results will hopefully serve as reference for future intervention studies. -- La denutrition est une condition frequente parmi les patients hospitalises, augmentant la morbi-mortalite, la duree du sajour, et les couts de la sante. Peu d’etudes se sont interessees a la prevalence de la denutrition et sa prise en charge en Suisse. En fait, il existe tres peu d’information concernant les determinants de la denutrition et ses consequences sur la sante et les couts. L’objectif de ce travail etait de mieux caracteriser la prevalence, les determinants, la prise en charge et les consequences de la denutrition parmi les patients hospitalises en Suisse. Pour ce faire, cinq etudes ont ete conduites : une revue de la litterature, deux etudes transversales, une etude diagnostique et une analyse temporelle. La revue de la litterature a montre qu’en Europe la denutrition represente un cout financier considerable, pouvant aller jusqu’a 10% des depenses nationales de sante. La premiere etude transversale a ete conduite a l’hopital universitaire de Lausanne et a montre que trois patients sur cinq etaient a risque de denutrition, mais que seulement la moitie beneficiait d’une prise en charge. Cette etude a egalement montre que les patients a risque avaient une plus grande mortalite intra-hospitaliere et coutaient plus cher, alors que les taux de remboursement etaient moindres. Par ailleurs, l’etude diagnostique a montre que le codage de la denutrition avait une bonne specificite (87%) mais une mauvaise sensibilite (43%) et une valeur predictive positive faible (28%), ce qui limite l’estimation de la prevalence de la denutrition par l’utilisation des codes. La seconde etude transversale a porte sur les donnees de la statistique hospitaliere suisse ; elle a montre de grandes disparites regionales concernant le codage et la prise en charge de la denutrition, dues a l’absence de recommandations au niveau national. Finalement, l’analyse temporelle de la statistique hospitaliere suisse pour la periode 1998-2014 a montre une augmentation considerable de la frequence des codes de denutrition (de 0.18% a 2.13% au Tessin et de 0.23% a 5.63% an Mittelland). Neanmoins, en 2014, encore 40% des hospitalisations ayant un code de denutrition n’avaient pas de code associe a une intervention nutritionnelle. Dans l’ensemble, ce travail a permis d’obtenir des donnees concernant la prevalence, les determinants et l’impact de la denutrition dans les hopitaux suisses. Nous esperons que ces resultats pourront servir de reference pour de futures etudes d’intervention.