Impact Analysis of DRG Payment Reform on Resource Allocation Patterns and Hospitalization Outcomes for Lung Cancer Inpatients (2019-2023)

Objective Globally adopted and implemented, as a contemporary hospital management methodology, DRGs demonstrate threefold effectiveness: cost-efficiency improvement in medical spending, advancement of clinical service quality, and rigorous maintenance of treatment safety protocols. Through empirical analysis of lung cancer inpatient data, this study quantifies the policy's effects on medical expenditure patterns and medical services efficiency metrics, offering evidence-based insights for healthcare resource management optimization. Methods Utilizing interrupted time series (ITS) analysis, we developed a segmented regression model to evaluate the DRG-based payment reform's longitudinal effects on healthcare expenditure and care duration for pulmonary oncology patients at a regional tertiary hospital in Northwest China. The dataset encompassed 1076 inpatients from January 2019 to December 2023, capturing pre- and post-policy implementation phases (2021 demarcation). Results The analytical cohort comprised 1,076 consecutively admitted pulmonary carcinoma patients. Interrupted time series analysis revealed three distinct patterns of DRG reform impact: (1) Non-significant immediate effects were observed in total hospitalization costs (β=-¥1,365.53, P=0.684), treatment expenses (β=¥147.51, P=0.524), and length of stay (β=-0.10 days, P=0.944), with stable longitudinal trends post-implementation; (2) Material expenses not demonstrated reduction (β=-¥1,433.07, P=0.426) without sustained pattern alteration; (3) Notably, diagnosis expenses exhibited both significant level shift (Δ=+¥1,953.74, P<0.001) and progressive monthly escalation (β=+¥72.18, P=0.035), while drug costs manifested pronounced policy-induced increase (Δ=+¥4,963.67, P<0.001) with accelerated growth trajectory (β=+¥147.38/month, P=0.001). Conclusion While DRG-based payment reform as an essential resource allocation mechanism in healthcare financing reform, our empirically validated findings reveal paradoxical outcomes in lung cancer inpatients. The implementation demonstrated limited efficacy in curtailing aggregate hospitalization expenses and LOS while provoking structural cost shifts characterized by marked escalation in diagnostic and pharmaceutical expenditures. These unintended economic consequences may inadvertently precipitate clinical practice distortions, including therapeutic substitution patterns and diagnostic intensity amplification, potentially compromising both efficiency of pharmacoeconomicand medical services.