Health Economic Research on Oral Nutritional Supplements for Hospitalized Patients With Nutritional Risk

The goal of this observational study is to evaluate the treatment effect and health economic impact of oral nutritional supplements(ONS) in hospitalized patients with nutritional risk. The main questions it aims to answer are: * To evaluate the effect of ONS on clinical outcomes in hospitalized patients with high nutritional risk * To evaluate the health economic impact of ONS in hospitalized patients with high nutritional risk Data was collected from patients admitted to peking union medical college hospital between January 1, 2018 and December 31, 2020. The inclusion criteria were as follows: (1) age≥18 years old; (2)length of hospital stay≥3days; (3) Only ONS was used as enteral nutrition or no enteral nutrition was received. Exclusion criteria were: (1) age\<18; (2) length of hospital stay\<3 days; (3) the patients who received enteral nutrition other than ONS (such as tube feeding); (4) emergency admissions; (5) the patients who transferred from other hospitals; (6) pregnancy or lactation We collected the following data through the hospital big data query and analysis system: 1. Basic information: gender, age, height, weight, medical insurance, etc. 2. Clinical information: admission paths, admission time, admission departments, discharge time, discharge unit, length of stay, mode of payment； 3. Disease Information: admission diagnosis, disease coding at admission, the first discharge diagnosis, the coding of first discharge diagnosis, the second discharge diagnosis, the third discharge diagnosis, outcome (recovery, improvement, not cured, death, transfer to another hospital) 4. Operation information: surgical name, surgery code, 5. oral nutritional supplement: drug names, unit price 6. laboratory examination: hemoglobin, albumin, prealbumin 7. hospitalization costs: total cost, self-pay cost, other cost, the type of medical insurance； Researchers will compare ONS group to see the clinical outcomes and health economic impact.