title: Epidemiologic and diagnostic aspects of bacteriuria: a longitudinal study in older women.
abstract: OBJECTIVE
  To examine month-by-month variability of bacteriuria in a cohort of older women and to evaluate the performance of rapid diagnostic tests commonly used to indicate the presence of significant bacteriuria.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Community housing sites and a long-term care institution.
  
  
  METHODS
  Sixty-one women, mean age 77.6, took part in the study.
  
  
  METHODS
  Midstream clean-catch urine samples and medical information on subjects were collected at baseline, and then monthly for 6 months.
  
  
  RESULTS
  Bacteriuria alone (> or = 10(5) organisms per mL) occurred in 17% of all urine samples (28% of patients), bacteriuria with pyuria in 15% (26% of patients), and bacteriuria with symptoms in 3% (10% of patients). Spontaneous clearance of bacteriuria with pyuria was common (P = .30), as were new occurrences (P = .12) over 6 months of follow-up. For the outcome of bacteriuria with symptoms, sensitivity of urinary diagnostic tests such as bacteria and pyuria on microscopic analysis, and leukocyte esterase on dipstick testing, ranged from 79 to 93%. Negative predictive values of these tests approached 100%.
  
  
  CONCLUSIONS
  Bacteriuria was a very common event, occurring in almost one-fifth of all urine samples and one-third of all subjects during 6 months of follow-up. Month-by-month follow-up indicates that the natural history of bacteriuria is marked by frequent spontaneous alternation between positive and negative events. The high negative predictive value of many simple diagnostic tests commonly used for urinary tract disease suggests that they can quickly and cost-effectively rule out bacteriuria in the older female patient.
authors.affiliation: Program for the Analysis of Clinical Strategies, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: M
authors.initials: M
authors.lastname: Monane
authors.forename: J H
authors.initials: JH
authors.lastname: Gurwitz
authors.forename: L A
authors.initials: LA
authors.lastname: Lipsitz
authors.forename: R J
authors.initials: RJ
authors.lastname: Glynn
authors.forename: I
authors.initials: I
authors.lastname: Choodnovskiy
authors.forename: J
authors.initials: J
authors.lastname: Avorn
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000302:isolation & purification; D001437:Bacteriuria / Q000175:diagnosis / Q000453:epidemiology*; D001900:Boston / Q000453:epidemiology; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D015331:Cohort Studies; D015169:Colony Count, Microbial; D003430:Cross-Sectional Studies; D004927:Escherichia coli Infections / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D011776:Pyuria / Q000175:diagnosis / Q000453:epidemiology; D011934:Reagent Strips; D014552:Urinary Tract Infections / Q000175:diagnosis
chemical_list: D011934:Reagent Strips; C021443:leukocyte esterase; D002265:Carboxylic Ester Hydrolases