Abstract / Summary
Importance South Korea’s 2018 Life-Sustaining Treatment Decisions (LSTD) Act was enacted to promote patient autonomy, yet its impact on systemic antibiotic utilization near the end of life in patients with advanced cancer remains unexplored. Objective To evaluate shifts in systemic antibiotic use among end-of-life patients with advanced cancer following the LSTD Act. Design, Setting, and Participants This cohort study used the National Health Insurance Service database to evaluate decedents with 8 major advanced cancers (lung, liver, stomach, colorectal, pancreatic, prostate, gallbladder or biliary tract, and breast). Inverse probability of treatment weighting was performed to balance cancer types, comorbidities, and demographic characteristics. Data were collected and analyzed between October 2025 and February 2026. Exposures Implementation of the LSTD Act, comparing the pre–LSTD Act (2012-2017) and post–LSTD Act (2018-2023) eras. Main Outcomes and Measures The primary outcomes were antibiotic prescription proportion and days of therapy (DOT) per 1000 patient-days during the final 6 months of life. Broad-spectrum antibiotics, defined as antipseudomonal β-lactams, carbapenems, or glycopeptides, were separately analyzed. The utilization patterns were evaluated across 5 predefined intervals using odds ratios and risk ratios. A seasonally adjusted monthly interrupted time-series analysis was performed to characterize the longitudinal shifts in DOT during the final months of life. Results A total of 743 842 eligible decedents (mean [SD] age, 71.9 [12.2] years; 487 690 male [65.6%]) were evaluated, including 348 813 in the pre–LSTD Act era and 395 029 in the post–LSTD Act era. During the final 6 months of life, the overall prescription proportion increased from 88.3% to 90.8% (odds ratio, 1.34; 95% CI, 1.32-1.37), widening particularly in the final 3 months. Similarly, total antibiotic DOT showed a significant overall increase from 231.4 to 261.6 per 1000 patient-days (risk ratio, 1.14; 95% CI, 1.13-1.14) across all intervals. These 2 measures showed comparable trends across broad-spectrum antibiotics and other classes. Monthly interrupted time-series analysis revealed a significant postenactment slope increase in overall antibiotic DOTs (β = 0.94; 95% CI, 0.67-1.21; P < .001), driven largely by other antibiotics alongside the ongoing increase in broad-spectrum antibiotics. Conclusions and Relevance In this retrospective cohort study of patients with advanced cancer, the LSTD Act was not associated with reduced end-of-life antibiotic use, suggesting the need to reshape perceptions of antibiotics as potential life-sustaining therapy.