Tao Ge, Mengmeng Qiu, Taotao Shi, Dachang Qiu, Hao Wang, Pandi Chen, Maosong Chen
Higher pre-ICU platelet count CV was associated with mortality after adjustment for clinical covariates and platelet-monitoring frequency. The association was directionally reproduced in the external cohort, although the effect estimate was modest. Prospective studies with standardized platelet-sampling schedules are needed before clinical implementation.
BACKGROUND: Platelet count fluctuations are common in patients with intracerebral hemorrhage (ICH), but the prognostic relevance of these fluctuations remains uncertain.
METHODS: We conducted a retrospective multicenter cohort study using MIMIC-IV as the primary cohort and an independent Chinese cohort for external validation. Platelet count CV was calculated as the sample standard deviation divided by the mean of at least three observed, nonmissing platelet measurements obtained during the index hospitalization within 15 days before ICU admission. Missing measurement fields were excluded and were not treated as zero. Logistic regression, Cox models, restricted cubic splines, Kaplan-Meier analyses, subgroup analyses, reclassification metrics, and sensitivity analyses were performed. Primary multivariable models additionally adjusted for platelet measurement count, and effect estimates were reported per 0.1-unit increase in CV.
RESULTS: The primary cohort included 2,202 patients, of whom 294 died during the index hospitalization. After adjustment for clinical covariates and platelet measurement count, each 0.1-unit increase in platelet count CV was associated with in-hospital mortality (OR, 1.21; 95% CI, 1.07-1.38; p = 0.003), 28-day mortality (HR, 1.14; 95% CI, 1.04-1.26; p = 0.006), 90-day mortality (HR, 1.11; 95% CI, 1.02-1.21; p = 0.014), and 360-day mortality (HR, 1.11; 95% CI, 1.02-1.20; p = 0.016). Results were consistent in fixed-three-measurement and landmark sensitivity analyses. Adding platelet count CV produced modest reclassification improvement (continuous NRI, 0.209; 95% CI, 0.079-0.372; IDI, 0.007; 95% CI, 0.001-0.019). In the external cohort, platelet count CV was associated with 28-day mortality after multivariable adjustment (HR per 0.1-unit increase, 1.141; 95% CI, 1.007-1.292; p = 0.042).
CONCLUSION: Higher pre-ICU platelet count CV was associated with mortality after adjustment for clinical covariates and platelet-monitoring frequency. The association was directionally reproduced in the external cohort, although the effect estimate was modest. Prospective studies with standardized platelet-sampling schedules are needed before clinical implementation.