Table 2.

Multivariable logistic regression for 30-day readmission.

Variable	OR	95% CI	p value
Age (per 1 year)	1.002	1.000–1.004	0.067
Length of stay (per 1 day)	1.016	1.009–1.023	<0.001
Total cost (per 1 CNY)*	1.000	1.000–1.000	0.003
Year (2024 vs. 2023)	1.004	0.949–1.061	0.9
DRG group*	—	—	<0.001 (overall)

Total cost was modeled in its original unit (1 Chinese Yuan), which produces OR values close to 1 due to the scale.

*DRG category includes 67 groups after merging categories with fewer than 200 observations. DRG variables were entered as dummy variables in the multivariable model.

OR, odds ratio; CI, confidence interval.