Serum creatinine and eGFR over recent years. eGFR is automatically estimated from serum creatinine and administrative databases containing gender and date of birth information. In April 2019, a marked decrease in eGFR (red data point representing clinical biochemistry records) was not associated with an increase in serum creatinine. The decrease in eGFR was traced to a change in the administrative gender from male to female, which resulted in an automatic switch from the male to the female CKD-EPI equation. The blue data points represent eGFR values estimated from the male CKD-EPI equation.