Risk factors associated with acute pyelonephritis in healthy women.
BACKGROUND
Although most cases of acute pyelonephritis occur in otherwise healthy women, data on risk factors for this condition are lacking.


OBJECTIVE
To evaluate infection characteristics, incidence, and risk factors associated with acute pyelonephritis in a sample of women.


METHODS
Population-based case-control study.


METHODS
Group Health Cooperative, a prepaid health plan in Washington.


METHODS
788 nonpregnant women, 18 to 49 years of age. Case-patients (n = 242) were women with pyelonephritis who were identified from computerized databases. Controls were 546 similar-age women with no pyelonephritis diagnosis in the previous 5 years who were randomly selected from enrollment databases. Response rates for case-patients and controls were 73% and 64%, respectively.


METHODS
Characteristics of infection and potential risk factors for pyelonephritis, ascertained through computer-assisted telephone interview and computerized databases.


RESULTS
7% of case-patients were hospitalized. Escherichia coli was the infecting pathogen in 85% of cases. In multivariable models, factors associated with pyelonephritis risk were frequency of sexual intercourse in the previous 30 days (odds ratio, 5.6 [95% CI, 2.8 to 11.0] for > or =3 times per week), recent urinary tract infection (UTI) (odds ratio, 4.4 [CI, 2.8 to 7.1]), diabetes (odds ratio, 4.1 [CI, 1.6 to 10.9]), recent incontinence (odds ratio, 3.9 [CI. 2.6 to 5.9]), new sexual partner in the previous year (odds ratio, 2.2 [CI, 1.4 to 3.6]), recent spermicide use (odds ratio, 1.7 [CI, 1.1 to 2.8]), and UTI history in the participant's mother (odds ratio, 1.6 [CI, 1.1 to 2.5]). Risk factors for selected subgroups (patients < or = 30 years of age, patients > 30 years of age, patients with no UTI history, and inpatients) were also evaluated.


CONCLUSIONS
Potential recall bias, reliance on automated case definition criteria, and limited data on diabetes and incontinence variables.


CONCLUSIONS
Few nonpregnant, community-dwelling women younger than 50 years of age with pyelonephritis are hospitalized. As with cystitis in reproductive-age women, sexual behaviors and patient and family history of UTI are associated with increased pyelonephritis risk. Diabetes and incontinence also seem to independently increase the risk for pyelonephritis.
Scholes
Delia
D
Group Health Cooperative and University of Washington, Seattle, Washington, USA. scholes.d@ghc.org
Hooton
Thomas M
TM
Roberts
Pacita L
PL
Gupta
Kalpana
K
Stapleton
Ann E
AE
Stamm
Walter E
WE
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003556:Cystitis / Q000150:complications; D048909:Diabetes Complications; D004927:Escherichia coli Infections / Q000175:diagnosis; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011704:Pyelonephritis / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D012307:Risk Factors; D012725:Sexual Behavior; D013089:Spermatocidal Agents / Q000008:administration & dosage; D014550:Urinary Incontinence, Stress / Q000150:complications
D013089:Spermatocidal Agents