Changes in neonatal inpatient resource utilization and cost drivers under payment reform: a five-year retrospective...

To characterize temporal changes in neonatal inpatient case mix, resource utilization, and hospitalization costs from 2020 to 2024, with particular attention to cost-structure changes around the January 2022 payment reform, and to identify key clinical factors associated with hospitalization costs.

This single-center retrospective study enrolled neonates admitted between January 2020 and December 2024 with valid total hospitalization costs and length of stay (LOS). Descriptive statistics characterized annual case mix and cost trends. Gestational age (GA)-standardized cost indices and daily cost intensity were calculated to assess resource consumption across different case mixes. With January 2022 designated as the reform index point, interrupted time series (ITS) analysis was applied to evaluate temporal changes in the proportions of procedural fees and Western medicine fees. Gamma generalized linear models (GLM), quantile regression, and ordinary least squares (OLS) regression were performed to examine factors associated with hospitalization costs.

A total of 12,011 neonates were included. Annual admissions declined from 2,986 in 2020 to 1,952 in 2024 (a 34.6% decrease), while the proportion of extremely preterm infants rose from 0.7% to 2.4% and the proportion requiring mechanical ventilation increased from 27.1% to 39.3%. The overall median annual hospitalization cost remained relatively stable (9,588 to 10,498 CNY), but the GA-standardized cost index consistently exceeded the unadjusted level (12,811 to 15,136 CNY). After the January 2022 reform index point, the proportion of procedural fees increased immediately by 32.30 percentage points (P < 0.001), while no concurrent significant change was observed in the proportion of Western medicine fees. Costs were highly concentrated, with the top 5% of patients across all study years accounting for 31.4% of total costs. Daily cost intensity was highest in extremely preterm infants (1,997 CNY/d). Multivariable analysis showed that LOS (exp β = 1.045) and mechanical ventilation (exp β = 1.81) were the most important factors associated with increased hospitalization costs.

Neonatal admissions declined over the study period, while proportions of high-risk cases and cost concentration increased. LOS and mechanical ventilation were strongly associated with higher hospitalization costs, indicating that risk adjustment is essential in neonatal payment policies and resource allocation.