Supplementary file 1_Association of the systemic immune-inflammation index with consciousness disturbance in cerebral venous sinus thrombosis: a retrospective cohort study.docx

Logistic regression using eight LASSO-consensus features achieved AUROC 0.840 ± 0.092 with a train-test gap of 0.028 in the prespecified fixed-feature repeated cross-validation. A like-for-like fixed-feature logistic-regression comparison showed that the three-predictor model retained similar discrimination to the eight-feature model (mean per-fold AUROC 0.837 ± 0.091 vs. 0.840 ± 0.092) with a smaller train-test gap (0.004 vs. 0.028).

The full-pipeline nested sensitivity analysis yielded AUROC 0.800 (95% CI 0.717–0.869). Patients in the highest SII quartile had 11.62-fold higher fully adjusted odds of CD than those in the lowest quartile (95% CI 2.82–47.87; P-trend = 0.0004). The spline supported an overall association (P <0.001) but not statistically significant nonlinearity (P = 0.151).

In component sensitivity analyses, SII had greater unadjusted discrimination than neutrophil count, lymphocyte count, or platelet count (AUROC 0.783 vs. 0.638, 0.575, and 0.575, respectively).</p>Conclusions<p>Higher acute-phase SII was associated with CD in this cohort. The fixed-feature and full-pipeline nested analyses provide complementary internal evidence; prospective, temporally resolved, multicentre external validation is required before clinical use.</p>