Optimise Identification and Management of Chronic Kidney Disease

Dr Raj Thakkar and Dr Jim Moore Discuss the Importance of Early Diagnosis of Chronic Kidney Disease, Providing Practical Advice for Primary Care Practitioners

Chronic kidney disease (CKD) is a long-term condition characterised by abnormal kidney structure or function, which is defined by the presence of kidney damage, decreased kidney function, or both, for at least 3 months.^1,2 CKD prognosis is classified based on cause, glomerular filtration rate (GFR) category, and degree of albuminuria (indicated by urinary albumin:creatinine ratio [ACR])—see Figure 1.^1–3 

Figure 1: Prognosis of CKD by GFR and Albuminuria Categories¹

The Burden of CKD

CKD places a huge burden on patients, their families, and the economy. It is estimated that around 15% of people aged 35 years or older in England have CKD, and the condition results in an annual cost of approximately £1.4 billion to the NHS.^4,5

In addition, CKD confers significant cardiovascular risk, and is one of the six high-risk conditions for the development of cardiovascular disease (CVD) recognised by CVDPREVENT, the national primary care audit for CVD prevention.⁶ CKD alone appears to confer a greater risk of cardiovascular events than diabetes,⁷ and this risk is amplified in patients with diabetic kidney disease (DKD).⁸ The cardiovascular risk of CKD is further elevated by increased ACR or decreased estimated GFR (eGFR), as both are associated with a greater risk of adverse CKD outcomes and are independently associated with early mortality, even at early stages.^1,9–12 In combination, increased ACR and decreased eGFR multiply the risk of adverse outcomes, as can be seen from the standard categorisation of CKD risk outlined in Figure 1.^9,10,12

Furthermore, CKD can have significant detrimental consequences, and patients may require dialysis or kidney transplantation in end-stage renal disease (ESRD).^13,14 According to the 2017 National CKD Audit (NCKDA), for every 100 patients with CKD and moderate-to-severe impairment of kidney function, each year there are:¹³

• seven acute kidney injury events
• six cardiovascular events
• seven deaths
• 38 unplanned hospital admissions
• two admissions to an intensive care unit.

The detrimental consequences of CKD and the burden it imposes highlight the importance of early identification, diagnosis, and management for optimising patient outcomes. 

Early Diagnosis

Because CKD is often asymptomatic until it is at an advanced stage, many people with the condition remain undiagnosed—in fact, a 2020 population-based cohort study estimated that, without screening, as many as 44% of cases are going undiagnosed in the UK.^4,11 These missed cases reflect the suboptimal investigation of potential CKD in primary care.

When to Suspect CKD

Some patient groups are at increased risk of developing CKD, including those with established CVD, hypertension, diabetes, or gout, and those taking nephrotoxic drugs.¹⁵ The disease should be suspected in patients with risk factors for CKD, or possible clinical features or an incidental finding of:¹⁶

• ‘raised serum creatinine levels and/or a serum [eGFR] of less than 60 ml/min/1.73 m²
• proteinuria (a [urinary ACR {uACR}] of more than 3 mg/mmol)
• persistent haematuria (two out of three urine dipstick tests show[ing] 1+ or more of blood), after exclusion of a urinary tract infection …
• urine sediment abnormalities, such as red blood cells (may indicate glomerular disease); white blood cells (may indicate pyelonephritis or interstitial nephritis); or granular casts and renal tubular epithelial cells (seen in many parenchymal diseases).’

NICE guidance emphasises that both eGFR and uACR must be checked whenever suspected CKD is investigated,^9,17 in part to ensure the early identification of CKD. However, the results of the 2017 NCKDA demonstrate that a large proportion of patients with risk factors for CKD do not have routine blood or urine tests to test for this comorbidity.^13,18 Specifically, as of 2017:¹³

• 86% of people with diabetes were tested for CKD annually, but only 54% underwent the requisite urine tests
• fewer than 30% of people with CKD risk factors other than diabetes underwent uACR tests for CKD
• almost all general practices in England had given eGFR tests to over 90% of their patients with hypertension in the preceding 5 years, but they had only given uACR tests to 10–50% of these patients.

Gaps in uACR testing contribute to both underdiagnosis of CKD and underestimation of its risk and severity.^11,13,19 As such, the report on the NCKDA’s findings identified increased uACR testing as an essential improvement in all healthcare sectors.^13,18

Best Practice in the Management of CKD

Both NICE and Kidney Disease: Improving Global Outcomes have developed clinical guidelines for the identification and management of kidney diseases.^9,20 In general, the management of CKD should include treatment of underlying conditions, prevention of disease progression, symptomatic relief, and optimal management of comorbidities, such as hypertension and diabetes, and complications, such as anaemia.^9,21

Pharmacological Treatment of CKD

The mainstay of CKD treatment is renin–angiotensin–aldosterone system inhibitor (RAASi) therapy, with angiotensin-converting enzyme inhibitors (ACEis) or angiotensin-receptor blockers (ARBs).⁹ Therapeutic options are primarily guided by the person’s ACR and therapeutic response, and any comorbidities.⁹ Titration of these therapies to the maximum licensed dose that each patient can tolerate is essential.⁹ 

NICE’s recommendations on therapy for proteinuria in CKD are outlined in Figure 2.^9,22

Figure 2: NG203 Visual Summary: CKD Assessment and Management—Managing Proteinuria²²

Pharmacotherapy for Diabetic Kidney Disease

Patients with DKD are at a greater risk of morbidity, including ESRD and premature mortality, than patients with CKD alone.²³ For these patients, consideration can be given to the addition of a sodium–glucose co-transporter-2 inhibitor (SGLT2i)²⁴—at the time of publication, dapagliflozin was the only SGLT2i licensed for this indication.^25,26

Finerenone is a relatively new, highly selective, nonsteroidal mineralocorticoid receptor antagonist^27,28 that has been shown to reduce the risk of CKD progression and cardiovascular events in patients with concomitant CKD and type 2 diabetes compared with placebo.²⁹ Indeed, in March 2023, NICE released new technology appraisal guidance for the use of finerenone in adults with stage-3 and -4 CKD (with albuminuria), type 2 diabetes, and an eGFR of 25 ml/min/1.73 m² or greater, as an add-on to optimised standard care with RAASi therapy and an SGLT2i.²³

The Role of the Primary Care Team

Given the detrimental consequences of CKD, the advent of therapies like finerenone and SGLT2is, which can slow disease progression, places even greater importance on identifying and managing CKD early in the course of the disease. Primary care teams play an essential role in these efforts by proactively identifying people with, or at risk of, CKD and undertaking eGFR and uACR testing accordingly.¹³

Correct Coding

Another improvement that the NCDKA report identified as essential in CKD management is accurate coding in clinical systems; in the audit, only 70% of biochemically confirmed cases of CKD were correctly coded, and high regional variability was evident in the accuracy of coding practices.¹³ Once a diagnosis is confirmed, clinicians must code patients accurately on clinical systems, thereby helping to optimise management of the patient’s CKD and comorbidities and ensure regular review of their kidney function. Improving CKD coding may also contribute to safer prescribing, reduce emergency hospital admissions, and allow the provision of personalised information and education on CKD to patients.^13,30

The PCCS CKD Quality Improvement Programme

The Primary Care Cardiovascular Society (PCCS) is a multidisciplinary society that promotes best practice in cardiovascular healthcare in primary care through education, training, and service development.³¹ Given the increased risk of cardiovascular events with CKD, and the need for training on CKD and quality improvement (QI) identified in the NCKDA report, the PCCS has developed an educational resource for primary care—the PCCS CKD Quality Improvement Programme—that practitioners can use to optimise the identification and management of CKD.^13,32

Developed in conjunction with primary and secondary care clinicians, the resource is designed to support primary care teams to enhance the quality of care for patients with, or at risk of, CKD. The programme presents an opportunity for primary care teams to transform their CKD care pathways and, by promoting earlier CKD diagnosis and evidence-based treatment optimisation, it represents a valuable resource for QI activities related to CKD. On a wider scale, the resource also supports primary care in delivering the CVD prevention ambitions of the NHS long term plan.^32,33

The programme comprises four modules encompassing all aspects of CKD identification and management.³² It is available to members of the PCCS as four educational videos on the Quality Improvement section of the PCCS website.³² Box 1 provides further details on each module.

Summary

CKD is a progressive condition and a leading cause of mortality worldwide.³⁴ Symptoms may not present until an advanced stage, and patients may eventually require dialysis or kidney transplantation. Healthcare teams must therefore act now to support early identification and prompt treatment of this disease. The PCCS aims to assist primary care in addressing this burden through its CKD QI programme.