Best Practices for Integrating within EHR Systems

The NKF Workgroup for Implementation of Race-Agnostic eGFR for Medication-Related Decisions has recommended the follow best practices for integrating within electronic health record (EHR) systems.

What should be available in an EHR

• Underlying data to enable all eGFR formulas
  • serum creatine (Scr)
  • serum cystatin C (cys)
  • age
  • BSA (calculated)
    • weight
    • height
• Importance of “current” height and weight
  • The definition of “current” varies based on the clinical situation.
  • In general, we recommend that for adult patients (≥ 18 years of age), the weight should be obtained within the last 5 days for hospitalized patients and within 1 year for ambulatory patients. However, since individual health systems may want to determine their own rules, we recommend that EHRs create a site-adjustable parameter.
  • If the value has been obtained outside of the desired time frame, the values should still be presented to the user with an appropriate warning and the option to update the value before showing a calculated eGFR.
  • The user should always have an option to modify the weight / height based on the clinical situation.
• Presentation of eGFR in the EHR
  • This information should be presented wherever eGFR values are needed for clinical decision making.
  • To avoid confusion, standardized eGFR (mL/min/1.73m²; used for disease staging) and one BSA-adjusted eGFR (mL/min; used for medication dosing) should be displayed to the user appropriately and clearly labeled with the equation name and units of measure.
    • Only the current formulas (i.e. race-agnostic CKD-EPI equations) should be used.
    • Only the BSA-adjusted eGFR (mL/min) should be shown on screens used for medication dosing.
    • These values should be rounded to the nearest mL/min (no decimals).
  • The result should be reported even when the result exceeds expected values.
  • Assuming availability of serum creatine (Scr) and/or serum cystatin C (cys) results, we recommend that the formulas be displayed in the priority order as presented in Table 1, but non-GFR determinants should always be considered when selecting the appropriate equation.
  • If either a Scr or cys value is not available, then the eGFR should be calculated based on the available value.

Table 1: Recommended Prioritization of eGFR Result Display

• Please note the College of American Pathologists (CAP) requires clinicians have access to information about the equation used to calculate eGFR results. We recommend that EHRs include such a comment when displaying eGFR calculations, preferably by including the equation name directly in the test name. This applies to both standardized (mL/min/1.73m²) and BSA-adjusted (mL/min) calculations.
• The standardized eGFR results (mL/min/1.73m²) should be retained for tracking over time
  • Retained results could be displayed in a flowsheet or other appropriate method
  • Historical values and trends are important to help understand changes in the patient’s kidney filtration function

• Medication dosing decision support at the point of order entry
  • Vendor systems should be designed such that kidney function measurements can be automatically used as inputs for dose range checking.
    • The values used should be displayed for the user to review and, as needed, users should be able to update those values for use in the calculation, this includes adding or updating any needed values which may already be in the EHR.
      • These include, but are not limited to, weight, height, and sex for clinical use.
      • Users should have an option to indicate if any added or changed values should update the system as a whole or are solely used for the current calculation.
    • We recommend that EHR and drug database vendors offer customers the option to perform dose screening based on eGFR_BSAadj (mL/min), regardless of the equations used in reference sources.
    • When reference sources (medication package label, pharmacy compendia) provide dose adjustments based on eCrCL, there should be an option to screen doses preferentially against eGFR_BSAadj. This race-agnostic eGFR_BSAadj should be directly obtained from the EHR using the available or entered measurements.
    • If the supplied eGFR is standardized to a BSA of 1.73m² (mL/min/1.73m²), the value should be adjusted for the patient’s BSA (mL/min), to individualize dosing.
    • When height and/or weight are unavailable, preventing the calculation of BSA and adjustment of the eGFR for the patient's BSA, it is acceptable to utilize the standardized eGFR.
      • When this occurs, prompt the user to enter the height and/or weight to enable the calculation of an eGFR_BSAadj.
• Certain drugs have dosing guidelines in kidney impairment that specify a certain type of  measurement as ideal. For example, the literature recommends that dofetilide dose adjustments be based on eCrCL calculated using Cockcroft-Gault eCrCL equation with actual body weight. Users should be made aware of these cases and understand the limitations of clinical decision support (CDS) systems to capture such nuances.