This cohort was an analysis based on patients from six stroke centers: the 2nd Affiliated Hospital of Zhejiang University; the First People's Hospital of Pinghu, Jiaxing; the First People's Hospital of Taizhou; the People's Hospital of Haiyan, Jiaxing; Tiantai County People's Hospital, Taizhou; the 2nd People's Hospital of Quzhou (Please see more information of this cohort in supplement). All hospitals are located in Zhejiang Province. Patients' data were entered by local trained registrars using standardised protocols, and the overall process of case registration, monitoring of the data quality, and inquiry and correction of erroneous data was managed and supervised by a steering committee.
We included adult patients who (1) admitted for primary ICH ; (2) underwent blood routine test (hemoglobin included) and CT scan as soon as they arrived at hospital; (3) were not treated with neurosurgical procedures. We excluded patients who (1) had ICH secondary to known causes, including trauma, intracranial neoplasm and systemic diseases12, as well as anticoagulative agents; or had isolated intraventricular hemorrhage (IVH); (2) mRS >2 before the current ICH episode (according to past medical records or description from guardians.
This study was approved by human research ethic committees at all participating centers, and conducted in compliance with the principles set forward by the Declaration of Helsinki.
