Socioeconomic status and mortality among dialysis patients: a systematic review and meta-analysis

BackgroundThe reported association between individual indicators of socioeconomic status (SES) and mortality in dialysis patients was inconsistent in previous studies. We performed a meta-analysis to identify the association between SES and mortality of dialysis population.MethodsThe meta-analysis was conducted in accordance with MOOSE guidelines. Cohorts evaluating the association between SES indicators (income, education and occupation) and mortality in dialysis patients were included. Random-effects models were used to pool the adjusted relative risk (RR) from individual studies. Heterogeneity was assessed by Cochrane's Q and the I-2 statistic. Subgroup analyses and sensitivity analyses were performed to identify sources of heterogeneity and to evaluate the robustness of findings.ResultsFourteen studies were finally included. In hemodialysis patients, increased mortality was associated with lower level of income (RR=1.08, 95%CI [1.01-1.16], P=0.035; I-2=87.9%, P<0.001) and occupation (RR=1.63, 95%CI [1.11-2.38], P=0.013; I-2=0.0%, P=0.601). However, no significant association was identified for education (RR=1.43, 95%CI [0.92-2.25]; P=0.112; I-2=68.3%,P=0.001). In patients receiving peritoneal dialysis, lower level of income (RR=1.80, 95%CI [1.12-2.88],P=0.015; I-2=75.9%, P=0.042), education (RR=1.27, 95%CI [1.13-1.43], P<0.001; I-2=0.0%, P=0.684), and occupation (RR=3.42, 95% CI [1.35-8.70], P=0.010) were risk factors for increased mortality. Subgroup analysis showed the association between SES indicators and mortality in hemodialysis differed according to geographic locations and study designs.ConclusionLower SES (measured by income, education, and occupation) tends to be associated with higher mortality in patients receiving maintenance dialysis. But the magnitude of the associations varied for different individual indicators of SES.