Conversion of Urine Protein-Creatinine Ratio or Urine Dipstick Protein to Urine Albumin-Creatinine Ratio for Use in Chronic Kidney Disease Screening and Prognosis: An Individual Participant-Based Meta-analysis.
Annals of internal medicine
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.
PRIMARY FUNDING SOURCE: National Institute of Diabetes and Digestive and Kidney Diseases and National Kidney Foundation.
Kidney & Diabetes
Sumida, Keiichi; Nadkarni, Girish N; Grams, Morgan E; Sang, Yingying; Ballew, Shoshana H; Coresh, Josef; Matsushita, Kunihiro; Surapaneni, Aditya; Brunskill, Nigel; Chadban, Steve J; Chang, Alex R; Cirillo, Massimo; Daratha, Kenn B; Gansevoort, Ron T; Garg, Amit X; Iacoviello, Licia; Kayama, Takamasa; Konta, Tsuneo; Kovesdy, Csaba P; Lash, James; Lee, Brian J; Major, Rupert W; Metzger, Marie; Miura, Katsuyuki; Naimark, David M J; Nelson, Robert G; Sawhney, Simon; Stempniewicz, Nikita; Tang, Mila; Townsend, Raymond R; Traynor, Jamie P; Valdivielso, José M; Wetzels, Jack; Polkinghorne, Kevan R; and Heerspink, Hiddo J L, "Conversion of Urine Protein-Creatinine Ratio or Urine Dipstick Protein to Urine Albumin-Creatinine Ratio for Use in Chronic Kidney Disease Screening and Prognosis: An Individual Participant-Based Meta-analysis." (2020). Articles, Abstracts, and Reports. 3407.