Relationship Between Red Cell Distribution Width And The Incidence And Poor Prognosis In Patients With Cerebral Infarction: A Meta-analysis

Object:1.To systemically evaluate the relationship between red cell distribution width and the incidence of cerebral infarction2.To systemically evaluate the poor prognosis predictive value of red cell distribution width in patients with cerebral infarctionMethod:We searched the relevant studies from PubMed,China National Knowledgedatabase,Wan fang database and China Biology Medicine database before December 2016with English search terms:cerebral infarction,brain infarction,cerebral ischemia,brain ischemia,cerebral ischemic stroke,ischemic stroke,cerebrovascular accident,red blood cell distribution width and Chinese search terms:cerebral infarction,ischemic cerebrovascular disease,ischemic stroke and red blood cell distribution width by standard search strategy and searching method with combination of free words and subject words.we also searched references of the eligible studies.We remove the duplicate studies and the apparently unrelated studies by going through the title and abstract and then determine the eligible studies according to the inclusion and exclusion criteria by reading the full text carefully.Then,we assessed the quality of studies and moderate or high quality studies were included.Of the eligible studies some relevant data were recorded.We used Stata12.0 to carry out the meta-analysis and calculate the pooled OR and 95%CI.The subgroup analysis were used to explore possible contributors to heterogeneity.The sensitivity analysis were defined to evaluate the stability of the pooled estimates.Potential publication bias was evaluated by funnel plot and Egger test.At last we analyze the pooled results and make conclusions carefully.Results:1.We identified 7 studies including 3 studies in Chinese language,RDW as continuous variable and 4 studies in English language,RDW as categorical variable,about the relationship between RDW and cerebral infarction.There was no significant heterogeneity between 3 studies with RDW as continuous variable(χ~2=0.42,P=0.813,I~2=0.0%)and a fixed-effects model was used.The pooled estimate for the incidence of cerebral infarction resulted in an association:OR=1.23,95%CI:1.17-1.28,P<0.001.There was a high heterogeneity between 4 studies with RDW as categorical variable(χ~2=22.44,P<0.001,I~2=86.6%)and a random-effects model was used.The pooled estimate for the highest compared with lowest category of RDW resulted in an association:OR=2.00,95%CI:1.26-3.16,P=0.003.2.We identified 8 studies including 6 studies in Chinese language and 2 studies in English language about the relationship between RDW and poor prognosis of cerebral infarction.There were 3 studies investigated the association of RDW as continuous variable with modified Rankin Scale>2.There was a moderate heterogeneity between 3studies with RDW as continuous variable(χ~2=5.9,P=0.052,I~2=66.1%)and a random-effects model was used.The pooled estimate for mRS>2 resulted in an association:OR=1.32,95%CI:1.10-1.58,P=0.003.There were 5 studies investigated the association of RDW as categorical variable with death.There was no significant heterogeneity between 5studies with RDW as categorical variable(χ~2=0.8,P=0.939,I~2=0.0%)and a fixed-effects model was used.The pooled estimate for the highest compared with lowest category of RDW resulted in an association:OR=7.13,95%CI:4.67-10.88,P<0.001.Conclusion:1.RDW was associated with the incidence of cerebral infarction,and increased RDW is a risk factor for the incidence of cerebral infarction.2.RDW was associated with the poor prognosis of patients with cerebral infarction and is the predictive factor for the poor prognosis.