The prevalence of chronic kidney disease in Australian primary care: analysis of a national general practice dataset

ABSTRACT Background There remains substantial variation in the reported prevalence of CKD in Australia. Using a large, nationally-representative general practice data source in Australia, we determined the contemporary prevalence and staging of CKD in Australian primary care. Methods We performed a retrospective, community-based observational study using healthcare data from MedicineInsight, a national general practice data source in Australia. The study included all adults with ≥1 visit to a general practice participating in the MedicineInsight program and ≥1 serum creatinine measurement (with or without a urine albumin-to-creatinine ratio [UACR] measurement) between 1 January 2011 and 31 December 2020; n=2,720,529 patients). The prevalence of CKD was estimated using three definitions: (1): an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m 2 or an eGFR ≥60 mL/min/1.73m 2 with a UACR ≥2.5 mg/mmol for males and ≥3.5 mg/mmol for females (definition 1), (2) two consecutive eGFR measures <60 mL/min/1.73m 2 at least 90 days apart or an eGFR ≥60 mL/min/1.73m 2 with a UACR ≥2.5 mg/mmol for males and ≥3.5 mg/mmol for females (definition 2), and (3) two consecutive eGFR measures <60 mL/min/1.73m 2 at least 90 days part and/or two consecutive UACR measures ≥2.5 mg/mmol for males and ≥3.5 mg/mmol for females at least 90 days apart (definition 3). Patient sociodemographic characteristics including comorbid conditions were assessed across the three definitions. Results The prevalence of CKD in the study cohort progressively increased over the 10-year study period, irrespective of the method used to define CKD. The annual prevalence of CKD varied across the three CKD definitions, with definition 1 resulting in the highest estimates. In 2020, the prevalence of CKD in the study cohort was 8.4% (n=123,988), 4.7% (n=69,110) and 3.1% (n=45,360) using definitions 1, 2 and 3, respectively. The number of patients with UACR measurements was low such that, among those identified as having CKD in 2020, only 3.8%, 3.2% and 1.5% respectively, had both eGFR and UACR measurements available in the corresponding year. Patients in whom both eGFR and UACR measurements were available mostly had moderate or high risk of CKD progression by local and international CKD guidelines (83.6%, 80.6% and 76.2%, respectively). Comorbid burden in patients with CKD was also frequently observed (coronary heart disease: 28.9%, type 2 diabetes: 38.5%, heart failure: 17.9%; using CKD definition 3). Conclusion In this large, nationally representative study, we observed an increasing trend in CKD prevalence in primary care settings in Australia. Most patients with CKD were at moderate to high risk of CKD progression with a significant comorbid burden including coronary heart disease and diabetes. These findings highlight the need for early detection and effective management to slow progression of CKD.