Statistical analysis
Intergroup comparisons of continuous variables were performed using
Student’s t-test or the Mann–Whitney U test. Comparisons of nominal
variables were performed using the chi-square test or Fisher’s exact
test. A receiver operating characteristic (ROC) curve was constructed
using GNRI, serum albumin level, BMI, and A-DROP score as the test
variables and in-hospital mortality events as the state variables. The
area under the ROC curves (AUCs) was used to compare the predictive
value of GNRI, albumin level, BMI, and A-DROP score. Logistic regression
analysis was performed to identify significant variables for in-hospital
mortality. Statistically significant variables were used in the
univariate model, and clinically relevant variables were further
analyzed using multivariate analysis. All statistical analyses were
performed using EZR (Saitama Medical Center, Jichi Medical University,
Saitama, Japan), a graphical user interface for R (The R Foundation for
Statistical Computing, Vienna, Austria).19 Statistical
significance was set at p < 0.05.