title: Diagnostic accuracy of urine dipstick for proteinuria in older outpatients.
abstract: BACKGROUND
  The urine dipstick is widely used as an initial screening tool for the evaluation of proteinuria; however, its diagnostic accuracy has not yet been sufficiently evaluated. Therefore, we evaluated its diagnostic accuracy using spot urine albumin/creatinine ratio (ACR) and total protein/creatinine ratio (PCR) in proteinuria.
  
  
  METHODS
  Using PCR ≥0.2 g/g or ≥0.5 g/g and ACR ≥300 mg/g or ≥30 mg/g as the reference standard, we calculated the diagnostic accuracy profile: sensitivity, specificity, positive and negative predictive value, and the area under the curve (AUC) of the receiver operating characteristic curve.
  
  
  RESULTS
  PCR and ACR were available for 10,348 and 3,873 instances of dipstick testing. The proportions with PCR ≥0.2 g/g, ≥0.5 g/g and ACR ≥300 mg/g, ≥30 mg/g were 38.2%, 24.6% and 8.9%, 31.7%, respectively. The AUCs for PCR ≥0.2 g/g, ≥0.5 g/g, and ACR ≥300 mg/g were 0.935 (trace: closest to ideal point), 0.968 (1+), and 0.983 (1+), respectively. Both sensitivity and specificity were >80% except for PCR ≥0.5 g/g with trace cutoff. For the reference standard of ACR ≥30 mg/g, the AUC was 0.797 (trace) and the sensitivity was 63.5%.
  
  
  CONCLUSIONS
  Urine dipstick test can be used for screening in older outpatients with ACR ≥300 mg/g or PCR as the reference standard for proteinuria. However, we cannot recommend the test as a screening tool with ACR ≥30 mg/g as the reference owing to its low sensitivity.
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Dongmin
authors.initials: D
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Soung Ha
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: One Zoong
authors.initials: OZ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Su Kyoung
authors.initials: SK
authors.lastname: An
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Hwe Won
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Kyoung Hyoub
authors.initials: KH
authors.lastname: Moon
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Myung Hee
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.
authors.forename: Beom
authors.initials: B
authors.lastname: Kim
keywords: Albuminuria; Proteinuria; ROC curve; Reagent strips