title: Diagnostic accuracy of urine dipstick testing in screening for microalbuminuria in type 2 diabetes: a cohort study in primary care.
abstract: BACKGROUND
  Clinical guidelines recommend annual screening for microalbuminuria in diabetes. Detection of microalbuminuria is important because it is associated with increased morbidity and mortality. Dipstick tests for microalbuminuria may be convenient, but their accuracy is uncertain.
  
  
  OBJECTIVE
  To assess the utility of urine dipstick testing for microalbuminuria in type 2 diabetes.
  
  
  METHODS
  In a 6-week cohort study in four general practices in Oxfordshire, UK, first-pass urine samples were obtained at two weekly intervals from patients with type 2 diabetes and tested in the practice using Micral-Test and Microalbustix urine dipsticks. Parallel samples were sent for laboratory albumin-creatinine ratio (ACR) assay. Results of single dipstick tests and sequences of dipstick and laboratory tests were compared with a clinical testing strategy based on current guidelines to assess the accuracy and estimate costs of testing.
  
  
  RESULTS
  The prevalence of microalbuminuria was 12.5% (n = 88). Mean (standard deviation) age was 68 (10) years, 56 (57%) were men. Median (interquartile range) diabetes duration was 6.2 (2.0-10.0) years. The sensitivity and specificity, respectively, of a single Micral-Test were 91.7% and 44.0% and of a Microalbustix test 33.3% and 92.0%. Testing strategies involving dipstick and laboratory ACR measurements or dipstick tests had similar accuracy. The costs of using dipstick tests were overall lower than laboratory ACR-based testing.
  
  
  CONCLUSIONS
  Dipstick testing in this study did not reliably identify diabetes patients with microalbuminuria. Although dipstick testing would decrease testing costs, it could either fail to diagnose most patients with microalbuminuria or increase the numbers of patients retested depending on the dipstick used.
authors.affiliation: Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
authors.forename: Alexander
authors.initials: A
authors.lastname: Nagrebetsky
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
authors.forename: Richard
authors.initials: R
authors.lastname: Stevens
authors.forename: Timothy
authors.initials: T
authors.lastname: James
authors.forename: Amanda
authors.initials: A
authors.lastname: Adler
authors.forename: Paul
authors.initials: P
authors.lastname: Park
authors.forename: Anthea
authors.initials: A
authors.lastname: Craven
authors.forename: Brian
authors.initials: B
authors.lastname: Shine
authors.forename: Andrew
authors.initials: A
authors.lastname: Farmer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000419:Albuminuria / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology / Q000652:urine; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000652:urine; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems / Q000191:economics; D015995:Prevalence; D011320:Primary Health Care; D011446:Prospective Studies; D011934:Reagent Strips / Q000191:economics; D012680:Sensitivity and Specificity
chemical_list: D011934:Reagent Strips