title: Utility of Urinary Protein-Creatinine Ratio and Protein Content in a 24-Hour Urine Collection in Systemic Lupus Erythematosus: A Systematic Review and Meta-Analysis.
abstract: To systematically review literature on the utility of spot urinary protein-creatinine ratio (PCR) as a screening test for proteinuria and its ability to accurately measure proteinuria compared with 24-hour urine collection (24H-P) in patients with systemic lupus erythematosus (SLE).
  
  
  
  We conducted a literature search (1900-2015) for articles comparing PCR and 24H-P in SLE patients in the databases Medline, Web of Science, and Embase. Included studies and their results were critically appraised and analyzed.
  
  
  
  Thirteen studies (1,001 patients; 84.01% women) were included. Ten studies reported on Pearson's correlation (range 0.67-0.94), and 3 studies reported on Spearman's correlation (range 0.78-1.00). The meta-analysis of studies with Pearson's correlation showed a high overall correlation of 0.80 between 24H-P and PCR, yet with high heterogeneity (I(2)  = 97.2%). Correlation analysis is not sufficient to evaluate the utility of a new test against the gold standard test, and analysis on agreement is required. Seven studies reported on agreement: 3 studies analyzed concordance correlation coefficient (0.48-0.94), 3 analyzed intraclass correlation coefficient (0.66-0.95), and 1 analyzed kappa coefficient (0.58). These results confirmed that the agreement between 24H-P and PCR was inappropriate. Three studies included Bland-Altman plots, and the results also demonstrated poor agreement between both tests.
  
  
  
  The PCR has a utility as a screening test for proteinuria in SLE patients. The studies' results of 24H-P and PCR showed poor agreement between both tests, signifying that PCR should not be a substitute for the gold standard test (24H-P) to accurately measure proteinuria.
authors.affiliation: University of Toronto Lupus Clinic, Toronto Western Hospital, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto, Ontario, Canada.
authors.forename: Jorge
authors.initials: J
authors.lastname: Medina-Rosas
authors.affiliation: University of Toronto Lupus Clinic, Toronto Western Hospital, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto, Ontario, Canada.
authors.forename: Kristy S
authors.initials: KS
authors.lastname: Yap
authors.affiliation: University Health Network, Toronto, Ontario, Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Anderson
authors.affiliation: University of Toronto Lupus Clinic, Toronto Western Hospital, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto, Ontario, Canada.
authors.forename: Jiandong
authors.initials: J
authors.lastname: Su
authors.affiliation: University of Toronto Lupus Clinic, Toronto Western Hospital, Centre for Prognosis Studies in the Rheumatic Diseases, Toronto, Ontario, Canada.
authors.forename: Zahi
authors.identifier: 0000-0001-5177-2076
authors.initials: Z
authors.lastname: Touma
mesh_terms: D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D008181:Lupus Nephritis / Q000175:diagnosis*; D008297:Male; D011506:Proteins / Q000032:analysis; D011507:Proteinuria / Q000175:diagnosis* / Q000209:etiology; D016482:Urinalysis / Q000379:methods*
chemical_list: D011506:Proteins; D003404:Creatinine