Clinical impact of lipid injectable emulsion in internal medicine inpatients exclusively receiving parenteral nutrition: a propensity score matching analysis from a Japanese medical claims database

BACKGROUND: Although guidelines recommend lipid injectable emulsions (ILEs) be used as a part of parenteral nutrition, many patients in Japan receive lipid-free parenteral nutrition. Furthermore, little is known about the effect of ILEs on clinical outcomes in medical inpatients managed with parenteral nutrition. The aim of this study was to investigate the clinical impact of ILEs on internal medicine inpatients receiving parenteral nutrition. METHODS: A propensity score matching (PSM) analysis was performed using a medical claims database covering 451 hospitals in Japan. Participants included the following internal medicine inpatients, ages ≥ 18 years, fasting > 10 days, and receiving exclusively parenteral nutrition, between 2011 and 2020. Participants were divided into 2 groups: those who did and did not receive ILEs. The primary endpoint was in-hospital mortality. The secondary endpoints included intravenous catheter infection, activities of daily living (ADL), hospital length of stay (LOS), and total medical costs. To adjust for energy doses, logistic or multiple regression analyses were performed using energy dose as an additional explanatory variable. RESULTS: After PSM, 19,602 matched pairs were formed out of 61,437 patients. The ILE group had significantly lower incidences than the non-ILE group of in-hospital mortality (20.3% vs. 26.9%; odds ratio [OR], 0.69; 95% confidence interval [CI], 0.66–0.72; p < 0.001), deteriorated ADL (10.8% vs. 12.5%; OR, 0.85; 95% CI, 0.79–0.92; p < 0.001), and shorter LOS (regression coefficient, − 0.8; 95% CI, − 1.6–0.0; p = 0.045). After adjusting for energy dose, these ORs or regression coefficients demonstrated the same tendencies and statistical significance. The mean total medical costs were $21,009 in the ILE group and $21,402 in the non-ILE group (p = 0.08), and the adjusted regression coefficient for the ILE vs. the non-ILE group was − $860 (95% CI, − $1252 to − $47). CONCLUSIONS: ILE use was associated with improved clinical outcomes, including lower in-hospital mortality, in internal medicine inpatients receiving parenteral nutrition. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12916-022-02568-x.