Acute Kidney Injury, Age, and Socioeconomic Deprivation: Evaluation of a National Data Set

Abstract

Introduction: This study examined the relationship among age, measures of social deprivation, and incidence and outcome of acute kidney injury (AKI). Methods: The Welsh National electronic AKI reporting system was used to identify all cases of AKI in patients 18 years or older between March 2015 and January 2017. Socioeconomic classification of patients was derived from the Welsh Index of Multiple Deprivation (WIMD). Patients were grouped according to their WIMD score, and Multivariate Cox proportional hazard modeling was used to adjust the data for age. The ranked data were categorized into percentiles and correlated with incidence, and measures of AKI severity and outcome. Results: Analysis included 57,654 patients. For the whole cohort, the highest 90-day survival was associated with the most socially deprived cohorts. There was a significant negative relationship between age-adjusted incidence of AKI and the WIMD score. In patients 60 years or older, there was an inverse correlation between WIMD score and survival that was not evident in those younger than 60. AKI severity at presentation was worse in patients from areas of social deprivation. Social deprivation was associated with a significantly higher proportion of preexisting chronic kidney disease (CKD) in patients with AKI older than 60, but not in those younger than 60. Conclusion: Overall mortality following AKI was higher in least-deprived areas, reflecting an older patient cohort. In contrast, social deprivation was associated with higher age-adjusted AKI incidence and age-adjusted mortality following AKI. The excess mortality observed in more deprived areas was associated with more severe AKI and a higher proportion of preexisting CKD. Keywords: AKI, CKD, epidemiology, mortality