Socioeconomic Status Predicts the Risk of Stroke Death: A Systematic Review and Meta-Analysis

Low socioeconomic status appears to be an independent risk factor for stroke mortality in epidemiology studies, but there has been no systematic assessment of this association. We performed a systematic review and meta-analysis evaluating the association between low socioeconomic status and stroke mortality. A systematic review of MEDLINE, EMBASE, and Web of Science for cohort studies that reported low socioeconomic status and stroke mortality was conducted from inception until July 2017. Research information, adjusted risk ratio (RR) estimates and 95% confidence intervals (Cls) were extracted. Estimates were pooled using a random-effects model. Heterogeneity was examined using the Q statistic and I-2. Twenty-seven prospective cohort studies (471,354,852 subjects; 429,886 deaths) assessing stroke mortality with low socioeconomic status were identified. Compared with the highest socioeconomic status, overall RR of stroke mortality was 1.39 (95% CI, 1.31-1.48) for those with the lowest after adjustment for confounding factors, but there was substantial heterogeneity between studies (I-2 = 89.9%, P = 0.001). Significant relationships were observed between risk of stroke mortality and the lowest education (RR = 1.21, 95% CI 1.11-1.33; I-2 = 70.9%, P < 0.001), income (RR = 1.54, 95% CI 1.30-1.82; I-2 = 91.6%, P < 0.001), occupation (RR = 1.54, 95% CI 1.35-1.75; I-2 = 78.3%, P < 0.001), composite socioeconomic status (RR = 1.37, 95% CI 1.25-1.51; I-2 = 69.5%, P = 0.001). After subgroup analysis, it was found that the heterogeneity of each SES indicator mainly came from the follow-up time, study population, stroke type, study area. Patients with low socioeconomic status had a higher risk of stroke mortality. The heterogeneity of income and occupation is larger, and the education and composite SES is smaller.