Socioeconomic status and chronic kidney disease at presentation to a renal service in the United Kingdom

Abstract

Background and objectives: Low socioeconomic status (SES) is associated with both development and progression of chronic kidney disease (CKD). The impact of SES on severity of CKD at presentation to a renal service is less well known. This study investigated the relationship between SES and severity of CKD in a retrospective, cross-sectional analysis involving 1657 patients at the Sheffield Kidney Institute (Sheffield, UK).

Design, setting, participants, & measurements: SES was assigned to each patient according to electoral ward of residence by postcode and ranked according to the corresponding British Index of Multiple Deprivation score, which comprises five deprivation quintiles (Q1, least deprived; Q5, most deprived). National Kidney Foundation Kidney Disease Outcomes Quality Initiative classification of CKD was used for stratification and analysis. Binary logistic regression analysis was applied for the association of variables/risk factors with CKD (lower GFR) at presentation.

Results: The age-adjusted prevalence of diagnosed CKD at presentation by area of residence, across the five deprivation quintiles, per million population was Q1 = 1495, Q2 = 3530, Q3 = 3398, Q4 = 3989, and Q5 = 19,599. Logistic regression models showed that living in the lowest SES quintile area (Q5) as compared with the highest SES (Q1) was associated with a greater risk for presenting with a lower estimated GFR, after adjustment for sociodemographic, lifestyle, and clinical variables.

Conclusions: Low SES is related to severity of CKD at presentation. Further studies are needed to examine this issue across the various SES categories in the United Kingdom.

Figure 1.

Crude distribution of prevalent chronic kidney disease (CKD) for the various wards of Sheffield. The darker shaded areas indicate higher rates of CKD.

Figure 2.

Index of Multiple Deprivation (IMD) scores for the same wards of the city. The darker shading indicates higher socioeconomic deprivation. A visual inspection reveals that the patterns are very similar to the map for CKD rates shown in Figure 1.

Figure 3.

Alternate deprivation score (UV67) for the wards of Sheffield, with a similar spatial pattern for the CKD prevalence rates as shown in Figure 1.

Figure 4.

Distribution of patients (%) with various stages of prevalent CKD (stages 3 through 5) across the five IMD quintiles (Q1 through Q5). There is an increasing trend of advanced CKD at presentation (stage 5; ▪) from the least (Q1) to the highest (Q5) IMD quintile (P = 0.012 for trend).