Sepsis-associated Thrombocytopenia and Platelet Transfusion （STAPT）

Inclusion Criteria: * Patients admitted to the ICU between January 2021 and May 2024 and subsequently discharged * Age ≥ 18 years * Meeting the Sepsis-3.0 diagnostic criteria * Platelet count \< 100 × 10⁹/L at ICU admission * ICU length of stay ≥ 48 hours Exclusion Criteria: * Active bleeding (e.g., major gastrointestinal bleeding, intracranial hemorrhage) or hematologic malignancies (e.g., leukemia, myelodysplastic syndrome, lymphoma); * Liver cirrhosis (Child-Pugh class B/C), chronic kidney disease (CKD stage 4-5), or autoimmune diseases (e.g., systemic lupus erythematosus); * Receipt of chemotherapy, immunosuppressants (e.g., cyclosporine, rituximab), or hematopoietic stem cell/solid organ transplantation within 2 weeks; * Pregnancy or lactation; * Pre-existing chronic thrombocytopenia (baseline platelet count \<100×10⁹/L for \>1 month) or long-term use of antiplatelet/anticoagulant drugs (\>2 weeks); * Significant baseline coagulation dysfunction at ICU admission:Prothrombin time (PT) \>1.5 times the upper limit of normal; Activated partial thromboplastin time (APTT) \>1.5 times the upper limit of normal; Fibrinogen level \<1.0 g/L; * APACHE II score ≥30 within 24 hours of ICU admission; * Missing \>20% of key data (e.g., daily platelet counts, ICU survival status within 28 days).