Table 1 Qualitative patient interview eligibility criteria

Demographics

• Male or female ≥ 18 years at the time of signing informed consent

• Speak fluent English

• Able to hold a 60-min conversation over the telephone independently

• Has access to a computer

• < 18 years at the time of signing informed consent

• Unable to speak fluent English

• Unable to independently hold a 60-min conversation over the telephone

• Does not have access to a computer

Diagnosis

• Stage 2/3a/3b CKD. Duration > 3 months

• Serum creatinine-based eGFR ≥ 30 and ≤ 89 mL/min/1.73 m² (CKD-EPI)

• No CKD. Stage 1/4 CKD

• Serum creatinine-based eGFR < 30 and > 89 mL/min/1.73 m² (CKD-EPI)

Comorbidities

• Type 2 diabetes mellitus (≤ 50% of study population)

• Type 1 diabetes mellitus (≤ 5% of study population)

• Hyperuricaemia (≤ 30% of study population)

• Type 2 diabetes mellitus (> 50% of study population)

• Type 1 diabetes mellitus (> 5% of study population)

• Hyperuricaemia (> 30% of study population)

• Autosomal dominant or autosomal recessive polycystic kidney disease

• Lupus nephritis or ANCA-associated vasculitis

• Autoimmune kidney diseases including glomerulonephritis

• Congenital urinary tract malformations

Therapy

• Current (or within 90 days) chronic or intermittent haemodialysis or peritoneal dialysis

• Receiving cytotoxic therapy, immunosuppressive therapy or other immunotherapy for primary or secondary renal disease within 6 months prior to enrolment

• Previously received an organ transplant

• NYHA class IV Congestive Heart Failure at the time of enrolment

• Myocardial infarction, unstable angina, stroke or transient ischaemic attack within 12 weeks prior to enrolment