Abstract: SA-PO427

Serum Creatinine from 29 US Health Care Organizations: The Case of Imprecise Measurement

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 302 CKD: Estimating Equations, Incidence, Prevalence, Special Populations

Authors

  • Stempniewicz, Nikita, AMGA, Alexandria, Virginia, United States
  • Ballew, Shoshana, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States
  • Ciemins, Elizabeth, AMGA, Alexandria, Virginia, United States
  • Grams, Morgan, Welch Center for Prevention, Epidemiology & Clinical Research, Baltimore, Maryland, United States
  • Matsushita, Kunihiro, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States
  • Penso, Jerry, AMGA, Alexandria, Virginia, United States
  • Coresh, Josef, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States
Background

For precise measurement of estimated GFR (eGFR), KDIGO 2012 guidelines recommend clinical laboratories report serum creatinine to the nearest 0.01 mg/dl. Rounding serum creatinine measurements to 0.1 mg/dl reduces the precision of eGFR, e.g., a female with a serum creatinine of 1.0 mg/dl, and ages of 60, 70, or 80 would represent eGFR (CKD-EPI) in the ranges of 58-64, 54-60, and 51-56 mL/min/1.73 m2, respectively. However, many laboratories still round to 0.1 mg/dl.

Methods

We analyzed 2.3 million patients with serum creatinine measurements from the electronic health record (EHR) data of 29 AMGA member organizations who use the Optum One population health analytics platform. We used the most recent serum creatinine recorded between 01/01/2013 and 12/31/2016 for patients age 18-99, with a history of hyperglycemia, and at least one ambulatory office visit.
Imprecision in serum creatinine reporting was quantified using the proportion of values with a 0 in the second place after the decimal (e.g., 0.90, 1.00). With precise measurement we expect ~10% of patients to end in each digit including 0.

Results

Overall, 36% of serum creatinine measurements had 0 for the second decimal place (e.g. X.X0, blue in Figure 1). This proportion varied among organizations, ranging from 10%-100%. Over the last 4 years the proportion with 0 in the second place after the decimal decreased from 51% (2013) to 34% (2016).

Conclusion

Imprecise measurement of serum creatinine by clinical laboratories in the US is improving but is still a prevalent practice which should be eliminated to meet with guidelines and improve the quality of health care.