Kidney function in healthcare clients in Khayelitsha, South Africa: Routine laboratory testing and results reflect distinct healthcare experiences by age for healthcare clients with and without HIV.

In South Africa, PLHIV are eligible for free ART and kidney function screening. Serum creatinine (SCr) laboratory test data from the National Health Laboratory Service are collated at the Provincial Health Data Centre and linked with other routine health data. We analysed SCr and estimated glomerular filtration rate (eGFR) results for PLHIV and HIV-negative healthcare clients aged 18-80 years accessing healthcare in Khayelitsha, South Africa and comorbidity profiles at SCr and eGFR testing. 45 640 individuals aged 18-80 years with at least one renal test accessed Khayelitsha public health facilities in 2016/2017. 22 961 (50.3%) were PLHIV. Median age at first SCr and eGFR test for PLHIV was 33yrs (IQR: 27,41) to 36yrs (IQR: 30,43) compared to 49yrs (IQR: 37,57) and 52yrs (IQR: 44,59) for those without HIV. PLHIV first median SCr results were 66 (IQR: 55,78) μmol/l compared to 69 (IQR: 58,82) μmol/l for HIV-negative individuals. Hypertension, diabetes, and CKD at testing were more common in HIV-negative people than PLHIV. HIV, diabetes and tuberculosis (TB) are associated with higher eGFR results; whilst hypertension, being male and older are associated with lower eGFR results. These data reflect testing practices in the Western Cape: younger people without HIV have generally worse kidney function test results; younger PLHIV have generally good test results, and older people with/without HIV have generally similar test results, reflecting regular screening for kidney function in asymptomatic PLHIV whereas young HIV-negative people are tested only when presenting with renal symptoms. Our analysis suggests we cannot infer the future healthcare requirements of younger PLHIV based on the current ageing population, due to changing ART availability for different generations of PLHIV. Instead, routine health data may be used in an agile way to assess ongoing healthcare requirements of ageing PLHIV, and to reflect implementation of treatment guidelines.