Helene Nordahl, PhD, et al, Department of Public Health, University of Copenhagen, Denmark, conducted a 14-year pooled cohort study to explore the effects of socioeconomic status, smoking, and hypertension on stroke risk. The results of the study were published online in August 2014 in the journal Stroke. Data from the study were obtained from seven population-based cohort studies conducted in Denmark, including a total of 68,643 male or female residents aged 30 to 70 years. An additive hazard model was used to analyze the effects of socioeconomic status, smoking, and hypertension on the risk of ischemic and hemorrhagic stroke and their interactions. The results showed that 3613 ischemic strokes and 776 hemorrhagic strokes occurred during the 14-year follow-up. Rates of hypertension and smoking were higher in those with low levels of education. Low education level was associated with an increased risk of ischemic stroke rather than hemorrhagic stroke. In addition, the joint effect of low education and smoking on ischemic stroke was higher than the sum of their individual effects, and this effect was more pronounced in the male population. There was no significant interaction between education level and hypertension. There was also a synergistic effect of hypertension and smoking on the occurrence of stroke (ischemic and hemorrhagic), which was most pronounced in women with ischemic stroke. Risk factors for stroke include age, race, social status, hypertension, smoking, diabetes mellitus, and dyslipidemia. Many studies have suggested that there are also significant interactions between different risk factors. Analysis of the interactions between these factors is important to identify target populations suitable for certain interventions. The results of this study demonstrate that smoking has a more pronounced effect on stroke risk in low-education and hypertensive populations than in the general population, suggesting that interventions targeting smoking behavior in these populations may be more effective in reducing the incidence of stroke in the population.