Admission C-reactive protein-to-albumin ratio and serum creatinine in relation to in-hospital mortality in non-HIV tuberculous meningitis: a retrospective cohort study.

Background: The independent and joint associations of admission C-reactive protein-to-albumin ratio (CAR) and serum creatinine with mortality in tuberculous meningitis (TBM) remain uncertain. Methods: We analyzed a single-center retrospective cohort of non-HIV patients hospitalized with TBM from October 2013 to January 2024. Exposure measurements were the first tests within 24 h of admission, before acute interventions. Multivariable logistic regression modeled both exposures continuously, adjusted for age nonlinearly and prespecified covariates, and tested exposure nonlinearity and interaction. Covariate-only multiple imputation generated 20 datasets. Cohort-specific upper-quartile groups were descriptive. An adult sensitivity analysis used estimated glomerular filtration rate (eGFR) calculated with the 2021 CKD-EPI equation. Results: Among 1,574 eligible patients, 187 died in hospital. The primary analysis included 1,563 patients and all 187 deaths; 11 survivors lacked CAR ( Conclusions: Admission creatinine had a nonlinear adjusted association with in-hospital mortality in non-HIV TBM. CAR yielded a near-null linear estimate, and the interaction analysis did not establish effect modification. Unmeasured neurological severity limits interpretation; these results do not define kidney dysfunction, a clinical cutoff, or a clinically useful prediction model.