Supplementary file 1_Injury mechanisms and occurrence locations among hospital-recorded cases in Lanshan District, Linyi, China, 2021–2025.docx

Leave-one-reporting-unit-out analyses assessed the stability of the main comparisons. Modified Poisson models with reporting-unit-clustered standard errors and Cramer’s V were used in sensitivity and descriptive analyses.</p>Results<p>Males contributed 40,433 records (59.19%). Blunt injuries were the most common mechanism (52,468; 76.81%); residences (29,529; 43.23%), roads/streets (22,346; 32.71%), and industrial/construction locations (10,829; 15.85%) were the most common locations.

The principal demographic comparisons were broadly consistent across reporting-unit deletion analyses. Males had higher sharp-versus-blunt (RRR 2.02, 95% CI 1.45–2.82) and industrial/construction-versus-residence RRRs (RRR 2.68, 95% CI 2.27–3.18), and a lower road/street-versus-residence RRR (RRR 0.87, 95% CI 0.83–0.92). Compared with adults aged 35–64 years, those aged 15–34 years had higher sharp-versus-blunt (RRR 1.61, 95% CI 1.02–2.53) and road/street-versus-residence RRRs (RRR 1.41, 95% CI 1.16–1.70).

Alcohol and psychotropic-substance estimates were imprecise and sensitive to reporting-unit removal.</p>Conclusion<p>Sex and age were associated with the composition of mechanisms and locations among hospital-recorded injury cases. The findings describe the surveillance case series and do not estimate population incidence or causal effects. Behavioral indicators should be interpreted as exploratory because positive records were sparse and disproportionately concentrated in the largest reporting unit.</p>