University of Leicester
Browse

File(s) under permanent embargo

Reason: Publisher prohibits availability through Institutional Repository

Conversion of Urine Protein–Creatinine Ratio or Urine Dipstick Protein to Urine Albumin–Creatinine Ratio for Use in Chronic Kidney Disease Screening and Prognosis

journal contribution
posted on 2020-07-22, 15:14 authored by Keiichi Sumida, Girish N Nadkarni, Morgan E Grams, Yingying Sang, Shoshana H Ballew, Josef Coresh, Kunihiro Matsushita, Aditya Surapaneni, Nigel Brunskill, Steve J Chadban, Alex R Chang, Massimo Cirillo, Kenn B Daratha, Ron T Gansevoort, Amit X Garg, Licia Iacoviello, Takamasa Kayama, Tsuneo Konta, Csaba P Kovesdy, James Lash, Brian J Lee, Rupert W Major, Marie Metzger, Katsuyuki Miura, David MJ Naimark, Robert G Nelson, Simon Sawhney, Nikita Stempniewicz, Mila Tang, Raymond R Townsend, Jamie P Traynor, José M Valdivielso, Jack Wetzels, Kevan R Polkinghorne, Hiddo JL Heerspink
Background: Although measuring albuminuria is the preferred method for defining and staging chronic kidney disease (CKD), total urine protein or dipstick protein is often measured instead.

Objective: To develop equations for converting urine protein creatinine ratio (PCR) and dipstick protein to urine albumin creatinine ratio (ACR) and to test their diagnostic accuracy in CKD screening and staging.

Design: Individual participant–based meta-analysis.

Setting: 12 research and 21 clinical cohorts.

Participants: 919 383 adults with same-day measures of ACR and PCR or dipstick protein.

Measurements: Equations to convert urine PCR and dipstick protein to ACR were developed and tested for purposes of CKD screening (ACR ≥30 mg/g) and staging (stage A2: ACR of 30 to 299 mg/g; stage A3: ACR ≥300 mg/g).

Results: Median ACR was 14 mg/g (25th to 75th percentile of cohorts, 5 to 25 mg/g). The association between PCR and ACR was inconsistent for PCR values less than 50 mg/g. For higher PCR values, the PCR conversion equations demonstrated moderate sensitivity (91%, 75%, and 87%) and specificity (87%, 89%, and 98%) for screening (ACR >30 mg/g) and classification into stages A2 and A3, respectively. Urine dipstick categories of trace or greater, trace to +, and ++ for screening for ACR values greater than 30 mg/g and classification into stages A2 and A3, respectively, had moderate sensitivity (62%, 36%, and 78%) and high specificity (88%, 88%, and 98%). For individual risk prediction, the estimated 2-year 4-variable kidney failure risk equation using predicted ACR from PCR had discrimination similar to that of using observed ACR.

Limitation: Diverse methods of ACR and PCR quantification were used; measurements were not always performed in the same urine sample.

Conclusion: Urine ACR is the preferred measure of albuminuria; however, if ACR is not available, predicted ACR from PCR or urine dipstick protein may help in CKD screening, staging, and prognosis.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases and National Kidney Foundation.

History

Citation

Annals of Internal Medicine, 2020, https://doi.org/10.7326/M20-0529

Author affiliation

Department of Health Sciences, University of Leicester

Version

  • AM (Accepted Manuscript)

Published in

Annals of Internal Medicine

Publisher

American College of Physicians

issn

0003-4819

eissn

1539-3704

Copyright date

2020

Language

en

Publisher version

https://www.acpjournals.org/doi/10.7326/M20-0529

Usage metrics

    University of Leicester Publications

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC