A prospective study of risk factors for symptomatic urinary tract infection in young women

N Engl J Med. 1996 Aug 15;335(7):468-74. doi: 10.1056/NEJM199608153350703.


Background: Although acute urinary tract infections are common in young women, the associated risk factors have not been defined prospectively.

Methods: We recruited sexually active young women who were starting a new method of contraception at a university health center or a health maintenance organization (HMO) and monitored them for six months for symptomatic urinary tract infections. Daily diaries and serial interviews were used to collect data on potential risk factors.

Results: Among 796 women, the incidence of urinary tract infections per person-year was 0.7 in the university cohort (mean age, 23 years; n = 348) and 0.5 in the HMO cohort (mean age, 29; n = 448). In both cohorts, there were strong dose-response relations between the risk of infection and both recent use of a diaphragm with spermicide (respective relative risks for one, three, and five days of use in the past week, 1.42, 2.83, and 5.68 in the university cohort, P<0.001; and 1.29, 2.14, and 3.54 in the HMO cohort, P=0.04) and recent sexual intercourse (respective relative risks for one, three, and five days with intercourse in the past week, 1.37, 2.56, and 4.81 in the university cohort, P<0.001; and 1.24, 1.91, and 2.96 in the HMO cohort, P=0.002). The risk of acute infection was also associated with a history of recurrent infection (relative risk, 5.58 in the university group and 2.10 in the HMO group) but not with cervical-cap use, ABO-blood-group nonsecretor phenotype, or delayed postcoital voiding.

Conclusions: Among sexually active young women the incidence of symptomatic urinary tract infection is high, and the risk is strongly and independently associated with recent sexual intercourse, recent use of a diaphragm with spermicide, and a history of recurrent urinary tract infections.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acute Disease
  • Adolescent
  • Adult
  • Coitus*
  • Contraceptive Devices, Female / adverse effects*
  • Female
  • Humans
  • Incidence
  • Marital Status
  • Multivariate Analysis
  • Proportional Hazards Models
  • Prospective Studies
  • Recurrence
  • Risk Factors
  • Spermatocidal Agents / adverse effects*
  • Urinary Tract Infections / epidemiology
  • Urinary Tract Infections / etiology*


  • Spermatocidal Agents