title: Factors associated with the geographic variation of reported Chlamydia infection in Minnesota.
abstract: OBJECTIVE
  In Minnesota, physicians have been required to report cases of Chlamydia trachomatis infection since 1985. The distribution of reported cases suggests that there is substantial geographic variation in the rate of chlamydia infection.
  
  
  OBJECTIVE
  We conducted chlamydia screening at selected sites and a survey of primary care physicians in counties with high and low rates of reported chlamydia infection. We hypothesized that chlamydia infections are uniformly distributed in nonmetropolitan areas, and the geographic differences in reported cases can be attributed to variable testing and reporting practices by physicians.
  
  
  METHODS
  The number of reported female chlamydia cases per 1,000 women was calculated for each rural Minnesota county in 1990. Fourteen counties with high and low rates of reporting were selected for further investigation. From September to December 1991, universal chlamydia screening was carried out at 11 clinics serving patients in these counties. A questionnaire was mailed to all primary care physicians in these counties.
  
  
  RESULTS
  In 1990, the rate of reported chlamydia cases was 4.7/100,000 and 0.1/100,000 for women living in the high-reporting and low-reporting counties, respectively. Chlamydia infection was present in 5.5% and 9.7% of women screened at selected clinics in high- and low-reporting counties, respectively. Physicians in high- and low-reporting counties did not differ significantly in terms of age, gender, number of pelvic exams, or frequency of chlamydia testing. However, physicians in high-reporting counties were significantly more likely to test for chlamydia when evaluating mucopurulent cervicitis or salpingitis, and they were more likely to test a woman whose sex partner had urethritis. Physicians in high-reporting counties were also more likely to have reported a case of chlamydia.
authors.affiliation: AIDS/STD Prevention Services Section, Minnesota Department of Health, Minneapolis 55440, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Belongia
authors.forename: S J
authors.initials: SJ
authors.lastname: Moore
authors.forename: R S
authors.initials: RS
authors.lastname: Steece
authors.forename: K L
authors.initials: KL
authors.lastname: MacDonald
mesh_terms: D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000517:prevention & control; D002692:Chlamydia trachomatis; D003430:Cross-Sectional Studies; D005194:Family Practice; D005260:Female; D006801:Humans; D019221:Mandatory Reporting; D008403:Mass Screening; D008910:Minnesota / Q000453:epidemiology; D011159:Population Surveillance; D010818:Practice Patterns, Physicians'; D015995:Prevalence; D012111:Residence Characteristics