Care processes and outcomes of deprivation across the clinical course of kidney disease: Findings from a high-income country with universal healthcare

Background
No single study contrasts the extent and consequences of inequity of kidney care across the clinical course of kidney disease.
Methods
This population study of Grampian (UK) followed incident presentations of AKI, and incident eGFR thresholds of < 60, <45 and < 30 in separate cohorts (2011–2021). The key exposure was area-level deprivation (lowest quintile of the Scottish Index of Multiple Deprivation). Outcomes were care processes (monitoring, prescribing, appointments, unscheduled care); long-term mortality; and kidney failure. Modelling involved multivariable logistic regression, negative binomial regression, and cause specific Cox models with/without adjustment of comorbidities.
Results
There were 41 313, 51 190, 32 171, and 17 781 new presentations of AKI, and eGFR thresholds < 60, <45 and < 30. 6.1–7.8% were from deprived areas, and (vs all others) presented on average five years younger, with more diabetes, pulmonary and liver disease. Those from deprived areas were more likely to present initially in hospital, less likely to receive community monitoring, less likely to attend appointments, and more likely to have an unplanned emergency department or hospital admission episode. Deprivation had greatest association with long-term kidney failure at the eGFR < 60 threshold (adjusted HR 1.48, 1.17–1.87), and this association attenuated with advancing disease severity (HR 1.09, 0.93–1.28 at eGFR < 30); with a similar pattern for mortality. Across all analyses the most detrimental associations of deprivation were at an eGFR < 60 threshold, AKI, males, and those aged < 65 years.
Conclusions
Even in a high-income country with universal healthcare, serious and consistent inequities of kidney care exist. The poorer care and outcomes with area-level deprivation were greater earlier in the disease course.