Cox regression analysis of risk factors and establishment of prediction model for recurrent acute ischemic stroke in 3-years follow-up

Abstract

Objective To investigate the risk factors and establish the Cox's regression model and the personal prognosis index for the recurrence of ischemic stroke in 3-year follow-up. Methods 1 058 patients were retrospectively reviewed consecutively diagnosed with ischemic stroke admitted to the Neurology Department of the Hebei united University Affiliated Hospital from January 1, 2013 to December 31, 2013. Cases were followed up since the onset of ischemic stroke. The follow-up was finished in January 1, 2016. Kaplan-Meier methods were used for recurrence rate description. Monovariant and multivariate Cox's proportional hazard regression model were used to analyze risk factors associated with recurrence. Thus, a recurrence model was set up. Results During the period of follow-up, 184 cases relapsed. The 1-year recurrence rate was 29.9 person-year, 2-year recurrence rate was 46.6 person-year, 3-year recurrence rate was 52.7 person-year. Monovariant and multivariant Cox's proportional hazard regression model showed that the independent risk factors associated with recurrence were age(X1)(RR=1.303; 95%CI: 1.019~1.666)history of heart disease(X2)(RR=1.788; 95%CI: 1.127~2.836), hypertension(X3)(RR=1.897; 95%CI: 1.097~3.280), diabetes(X4)(RR=1.674; 95%CI: 1.015~2.760), total cholesterol(X5)(RR=2.136; 95%CI: 1.396~3.266). The personal prognosis index(PI)of recurrence model was as the following: PI=0.265X1+ 0.581X2+ 0.640X3+ 0.515X4+ 0.759X5. Conclusions Age, history of heart disease, hypertension, disease progression, and total cholesterol are the independent risk factors associated with recurrence of ischemic stroke. The recurrence model and the personal prognosis index equation are successful constructed. Key words: Ischemic stroke; Recurrence; Risk factors; Cox's regression model; Prognosis index