title: Establishing equations to evaluate 24 hour urine protein excretion using routine urinalysis.
abstract: OBJECTIVE
  It is necessary to screen people at high risk for proteinuria with an economical, reliable and convenient method. The aim of this study is to establish a new approach to predict 24 h urine protein (24 h UP) by routine laboratory assays.
  
  
  METHODS
  Five centres were included and a total of 4211 hospitalized patients were enrolled. All samples were assayed for dipstick protein (DSP), specific gravity (SG), 24 h UP and serum albumin (ALB) simultaneously. 4211 patients were randomly divided into two groups for establishing and testing the equations. Equations were built by multiple log-linear regressions.
  
  
  RESULTS
  (i) DSP is significantly correlated to 24 h UP in a logarithmic pattern; (ii) SG interprets 24 h UP for specific DSP; (iii) Equation 1 = 0.203 × 10(dummy-variable F)  × [100 (SG-1)](-0.470) ; and (iv) Equation 2 = 13.366 × 10(dummy-variable F)  × [100 (SG-1)](-0.547)  × [ALB (g/L)](-1.130) The dummy-variable F had a point-to-point accordance to DSP (detailed in text).
  
  
  CONCLUSIONS
  Combination of DSP and SG can interpret normal-range proteinuria well, and helped by ALB, their interpretation for macro proteinuria is much improved. It is dependable and economical for routine urinalysis to evaluate pathological proteinuria by equation.
authors.affiliation: Chinese Kidney Center of PLA, First Affiliated Hospital of Beidaihe Sanatorium of Beijing Military Region, Qinhuangdao, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Xie
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Guanglei
authors.initials: G
authors.lastname: Chen
authors.forename: Deyang
authors.initials: D
authors.lastname: Kong
authors.forename: Zhuliang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wang
authors.forename: Ka
authors.initials: K
authors.lastname: Qi
authors.forename: Minghui
authors.initials: M
authors.lastname: Song
authors.forename: Lu
authors.initials: L
authors.lastname: Ma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D006801:Humans; D008297:Male; D055641:Mathematical Concepts; D008875:Middle Aged; D011507:Proteinuria / Q000652:urine*; D013997:Time Factors; D016482:Urinalysis / Q000379:methods / Q000706:statistics & numerical data; D055815:Young Adult
keywords: chronic kidney disease; dipstick assays; proteinuria; routine urinalysis