Low Adherence to Kidney Disease: Improving Global Outcomes 2012 CKD Clinical Practice Guidelines Despite Clear Evidence of Utility

Abstract

Introduction: Kidney Disease: Improving Global Outcomes (KDIGO) 2012 guidelines classify chronic kidney disease (CKD) risk or prognosis using estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR). We assessed patient characteristics and outcomes according to the KDIGO classification, using data from DISCOVER CKD (NCT04034992).

Methods: Data were extracted from the US integrated Limited Claims and Electronic Health Record Dataset and TriNetX databases, and the UK Clinical Practice Research Datalink linked to Hospital Episode Statistics and Office for National Statistics databases. Eligible patients were aged ≥18 years with CKD, and identified by 2 consecutive eGFR measures (5 to <75 ml/min/1.73 m2; ≥90 days apart [maximum 730]) from January 2008. Index date was the second eGFR measurement; patients were categorized using the UACR measure closest to the index. Outcomes included patient characteristics, eGFR or UACR measurement frequency, and clinical outcomes per baseline KDIGO classification.

Results: Across databases, only 8.6% of patients with 2 eGFR measures had ≥1 UACR measures. Among 123,807 eligible patients, prevalence of heart failure, hypertension, and type 2 diabetes increased with increasing albuminuria. Incidence rates of mortality and adverse cardiovascular and renal outcomes increased with declining baseline eGFR, and particularly with increasing albuminuria. Median number of eGFR and UACR tests per year post-index ranged from 1.6 to 2.5 and 0.5 to 0.6, respectively, across databases; there was no clear increase in UACR testing frequency following the KDIGO 2012 guidelines.

Conclusion: Albuminuria monitoring is critical for optimal risk stratification in CKD, and our findings highlight an imperative for more regular UACR testing in clinical practice.

Keywords: DISCOVER CKD; Kidney Disease: Improving Global Outcomes; chronic kidney disease; estimated glomerular filtration rate; retrospective; urinary albumin-to-creatinine ratio.

© 2022 International Society of Nephrology. Published by Elsevier Inc.

Figures

Graphical abstract

Figure 1

Patient flow diagram. CKD, chronic kidney disease; CPRD, Clinical Practice Research Datalink; eGFR, estimated glomerular filtration rate; LCED, Limited Claims and Electronic Health Record Dataset; RRT, renal replacement therapy; UACR, urinary albumin-to-creatinine ratio.

Figure 2

Frequency of (a) eGFR and (b) UACR testing during follow-up. Numbers of tests inferred from the number of days with a test result during follow-up post-index. CPRD, Clinical Practice Research Datalink; eGFR, estimated glomerular filtration rate; IQR, interquartile range; LCED, Limited Claims and Electronic Health Record Dataset; UACR, urinary albumin-to-creatinine ratio.

Figure 3

Impact of KDIGO 2012 guidelines on frequency of UACR testing during follow-up. Numbers of tests inferred from the number of days with a test result during follow-up post-index. UACR data were not available from before 2012 in LCED. Data are rates with 95% confidence intervals, calculated according to the method reported by Ulm, K. CPRD, Clinical Practice Research Datalink; KDIGO, Kidney Disease: Improving Global Outcomes; LCED, Limited Claims and Electronic Health Record Dataset; UACR, urinary albumin-to-creatinine ratio.

Figure 4

Patient categorization and baseline characteristics by KDIGO category at index. Color coding is based on odds ratio quartile (Q) for each outcome within each database: green = Q1 and below; yellow = Q1 to Q2; orange = Q2 to Q3; red = Q3 and above. CPRD, Clinical Practice Research Datalink; eGFR, estimated glomerular filtration rate; KDIGO, Kidney Disease: Improving Global Outcomes; LCED, Limited Claims and Electronic Health Record Dataset; UACR, urinary albumin-to-creatinine ratio.

Figure 5

Incidence rates per 100 PY of clinical outcomes during follow-up by KDIGO category. Data are incidence rate (95% CI), calculated as the number of specific events that occur during patient follow-up time at risk (time in the study until first event or loss to follow-up). Color coding is based on odds ratio quartile (Q) for each outcome within each database: green = Q1 and below; yellow = Q1 to Q2; orange = Q2 to Q3; red = Q3 and above. Kidney failure was defined as progression to CKD stage 5 (sustained eGFR ≤15 ml/min/1.73 m2) or initiation of chronic RRT for >30 days (2 dialysis codes 30–365 days apart) or kidney transplant. Mortality data were not available for US LCED, US TriNetX reports only in-hospital deaths, and incidence rates for some outcomes were not available where there were low patient or event numbers (e.g., LCED eGRF <15 ml/min/1.73 m2). CI, confidence interval; CPRD, Clinical Practice Research Datalink; CV, cardiovascular; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; hHF, hospitalization for heart failure; KDIGO, Kidney Disease: Improving Global Outcomes; LCED, Limited Claims and Electronic Health Record Dataset; MI, myocardial infarction; NA, not available (owing to low patient/event numbers); PY, patient-years; RRT, renal replacement therapy; UACR, urinary albumin-to-creatinine ratio.

Figure 5

Incidence rates per 100 PY of clinical outcomes during follow-up by KDIGO category. Data are incidence rate (95% CI), calculated as the number of specific events that occur during patient follow-up time at risk (time in the study until first event or loss to follow-up). Color coding is based on odds ratio quartile (Q) for each outcome within each database: green = Q1 and below; yellow = Q1 to Q2; orange = Q2 to Q3; red = Q3 and above. Kidney failure was defined as progression to CKD stage 5 (sustained eGFR ≤15 ml/min/1.73 m2) or initiation of chronic RRT for >30 days (2 dialysis codes 30–365 days apart) or kidney transplant. Mortality data were not available for US LCED, US TriNetX reports only in-hospital deaths, and incidence rates for some outcomes were not available where there were low patient or event numbers (e.g., LCED eGRF <15 ml/min/1.73 m2). CI, confidence interval; CPRD, Clinical Practice Research Datalink; CV, cardiovascular; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; hHF, hospitalization for heart failure; KDIGO, Kidney Disease: Improving Global Outcomes; LCED, Limited Claims and Electronic Health Record Dataset; MI, myocardial infarction; NA, not available (owing to low patient/event numbers); PY, patient-years; RRT, renal replacement therapy; UACR, urinary albumin-to-creatinine ratio.