OBJECTIVETo validate efficacy of cerebrovascular hemodynamic synthesized score (CVHS) for screening high risk population of stroke and relative risk (RR) for predicting stroke.

METHODSParticipants aged > or = 40 years and free of stroke were cluster sampled from Beijing, Shanghai, Fuzhou and Tangshan city in 5 centers. Investigation of risk factors of stroke and examination of cerebrovascular hemodynamic were carried out during baseline, and stroke incidence was surveyed during follow up. 26 690 people aged > or = 40 years were recruited, and 24 253 people agreed to participate (90.87%) with the effect as 23 741. Cerebral blood vessel analyzer (CBA) CV 300 was used to measure cerebrovascular hemodynamic synthesized index, including quantity of mean blood flow (Q(mean)), velocity of maximum blood flow (V(max)), velocity of minimus blood flow (V(min)), velocity of mean blood flow (V(mean)) pulse wave velocity (Wv), characteristic impedance of cerebrovascular net (Zcv), dilatation index (DI), resistance of vascular (Rv), development resistance (DR), capillary pressure (Cp), differential pressure (Dp). The CVHS was calculated by software according to the index measured directly.

RESULTSThere were 48 481 person-year followed and 182 stroke incidence occurred. Incidence of stroke was 3.75/1000 person-year in the multiple source people who aged > or = 40 years. Uni-variant analysis indicated that age and gender adjusted relative risk (RR) for stroke of low CVHS (< 75) was 9.3. There was significant dosage response between CVHS and RR of stroke. Multiple Cox regression showed that CVHS was the strongest predictive factor. Screening test evaluation showed that sensitivity, specificity, accuracy and Youden index of CVHS for screening were 80.77%, 67.55%, 67.65% and 0.48, respectively. The area under ROC curve (AUC) was 0.806.

CONCLUSIONIt seems that CVHS was the strongest and independent predictor of stroke and the efficacy for screening high risk population was also satisfactory. This kind of screening test could be an useful measure for preventing of the stroke occurrence.