Association of deprivation and its individual domains on outcomes in people with chronic kidney disease

Background: Due to the high correlation of chronic kidney disease (CKD) with other comorbidities, the sole effect of CKD on deprived people is not clear. In addition, there is a paucity of evidence in the literature linking isolated domains of deprivation to outcomes. This study aimed to examine whether deprivation was associated with adverse outcomes in patients with CKD, independent of cardiometabolic morbidities. Individual domains of deprivation were also evaluated.

Methods: A retrospective study of patients with non-dialysis-dependent CKD (ND-CKD) in the Salford Kidney Study to investigate the association of deprivation with outcomes. The English Indices of Deprivation was used for the comparative analysis of the five quintiles of deprivation. Two propensity score methods were used to attenuate the confounding effect of cardiometabolic morbidities between the least and the most deprived groups.

Results: People living in the least deprived areas (n = 319) had a lower risk of combined outcomes (all-cause mortality and renal replacement therapy) when compared with the most deprived group (n = 813) [hazard ratio (HR) 0.83; 95% confidence interval (CI) 0.71-0.98]. The negative association of deprivation remained after matching but with mixed statistical significance when using different propensity methods (HR 0.85; 95% CI 0.70-1.03 for propensity score matching and HR 0.77; 95% CI 0.61-0.98 for inverse probability weighting). The association of combined outcomes varied across component index of multiple deprivation domains with wide CIs. However, areas with lower scores for education, income and employment were significantly associated with a higher risk.

Conclusions: This study has identified that in people with ND-CKD, unemployment, poor educational attainment and lower household income were associated with poor outcomes. The association of deprivation with adverse outcomes persists despite adjustment for cardiometabolic morbidities.