Predictors of urinary tract infection after menopause: a prospective study.
OBJECTIVE
To describe the incidence of and risk factors for acute cystitis among nondiabetic and diabetic postmenopausal women.


METHODS
We conducted a population-based, prospective cohort study of 1017 postmenopausal women, aged 55 to 75 years, who were enrolled in a health maintenance organization and followed for 2 years. A wide range of behavioral and physiologic exposures were assessed at baseline interview and follow-up clinic visits; the main outcome measure was microbiologically confirmed acute symptomatic cystitis. Follow-up was 87% at 12 months and 81% at 24 months.


RESULTS
During 1773 person-years of follow-up, 138 symptomatic urinary tract infections occurred (incidence, 0.07 per person-year). Independent predictors of infection included insulin-treated diabetes (hazard ratio [HR] = 3.4; 95% confidence interval [CI]: 1.7 to 7.0) and a lifetime history of urinary tract infection (HR for six or more infections = 6.9; 95% CI: 3.5 to 13.6). Borderline associations included a history of vaginal estrogen cream use in the last month (HR = 1.8; 95% CI: 1.0 to 3.4), a history of kidney stones (HR = 1.9; 95% CI: 1.0 to 3.7), and asymptomatic bacteriuria at baseline (HR = 1.8; 95% CI: 0.9 to 3.5). Sexual activity, urinary incontinence, parity, postcoital urination, vaginal dryness, use of cranberry juice, vaginal bacterial flora, and postvoid residual bladder volume were not associated with incident acute cystitis after multivariable adjustment.


CONCLUSIONS
Insulin-treated diabetes is a potentially modifiable risk factor for incident acute cystitis among postmenopausal women, whereas a lifetime history of urinary tract infection was the strongest predictor. Use of oral or vaginal estrogen was not protective, and a wide range of behavioral and physiologic factors was not associated with acute cystitis episodes in this generally healthy sample.
Jackson
Sara L
SL
Northwest Health Services Research and Development Program, VA Puget Sound, Seattle, Washington, USA. sljack@u.washington.edu
Boyko
Edward J
EJ
Scholes
Delia
D
Abraham
Linn
L
Gupta
Kalpana
K
Fihn
Stephan D
SD
D000208:Acute Disease; D000368:Aged; D003075:Coitus; D015897:Comorbidity; D003556:Cystitis / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology; D004967:Estrogens / Q000008:administration & dosage; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000453:epidemiology*; D014622:Vaginal Creams, Foams, and Jellies
D004967:Estrogens; D014622:Vaginal Creams, Foams, and Jellies