Supplementary file 1_Short-term lagged exposure to ambient air pollutants and hospitalization costs among AMI patients: health-economic evidence from a low-pollution Chinese city with DRG/DIP standardized medical payment.docx

Benjamini–Hochberg false discovery rate (FDR) correction was used to control multiple testing bias. A sensitivity analysis restricted to 1,590 never-smoking patients was performed.</p>Results<p>Short-term exposure to SO₂, PM_2.5, PM₁₀, NO₂, and CO was significantly associated with elevated AMI medical expenditures, while O₃ showed no overall significant correlation.

Per natural log-unit elevation, SO₂ generated the largest cost increase (average 2.40%, ~729 CNY) with consistent adverse effects across all lag days; particulate pollutants PM_2.5 and PM₁₀ exhibited delayed peak risks at lag 4–5 days. In never-smokers, O₃ triggered significant cost rises at lag 3 and lag 5, indicating non-smokers as vulnerable subgroups susceptible to ozone toxicity.

Multicollinearity diagnostics validated the rationality of single-pollutant modeling.</p>Conclusions<p>Even low-level ambient air pollution compliant with current national standards increases the economic burden of AMI treatment, with SO₂ showing the strongest association. Smoking modifies cardiovascular cost-related effects of ozone. This population-level health-economic evidence supports stricter air quality regulations, and the integration of ambient exposure indicators into AMI risk stratification and public health resource allocation under the DRG/DIP payment system.</p>