title: Geographic clustering of adequate diagnostic follow-up after abnormal screening results for breast cancer among low-income women in Missouri.
abstract: OBJECTIVE
  In an effort to examine a cluster of late-stage breast cancer, this study reports (1) the extent of geographic variation in adequacy of diagnostic follow-up (ADFU) after abnormal breast cancer screening results across Missouri's counties and census tracts, (2) whether various personal characteristics or area poverty account for any geographic clustering observed, and (3) the association between area poverty rate and ADFU.
  
  
  METHODS
  We used 1998-2002 Missouri Show Me Healthy Women breast and cervical cancer program data from 2580 low-income women aged 50-64 who had abnormal breast cancer screening results. ADFU was based on established guidelines. Poverty rate was from the 2000 census data. We used 3 complementary statistical approaches.
  
  
  RESULTS
  Overall, 26.9% of screening results were inadequately followed up. County-level geographic variation accounted for 6.7% of the total variance in ADFU, while the census-tract-level variation was negligible. Women's sociodemographic characteristics, symptoms reported at time of screening, and screening results accounted for 25% of the county-level variation in ADFU. Statistically significant geographic variation in ADFU remained that could not be explained. Beyond 70 miles from the women's residence, the likelihood of receiving ADFU was geographically uncorrelated. We identified one large geographic cluster extending beyond the borders of counties and census tracts where women were less likely to receive ADFU (relative risk = 0.64; p = 0.01).
  
  
  CONCLUSIONS
  Efforts to improve the likelihood of ADFU should be directed at examining the relative contributions of the healthcare and social environments and characteristics of the women in the area where women were less likely to receive ADFU especially in the cluster area of late-stage breast cancer rather than targeting efforts at the county or census-tract level.
authors.affiliation: Department of Medicine, Division of Health Behavior Research, Washington University School of Medicine, St Louis, MO 63108, USA. mschootm@im.wustl.edu
authors.forename: Mario
authors.initials: M
authors.lastname: Schootman
authors.forename: Donna B
authors.initials: DB
authors.lastname: Jeff
authors.forename: William E
authors.initials: WE
authors.lastname: Gillanders
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Bruce
authors.initials: B
authors.lastname: Jenkins
authors.forename: Rebecca
authors.initials: R
authors.lastname: Aft
mesh_terms: D001943:Breast Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003266:Continuity of Patient Care; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008403:Mass Screening; D008875:Middle Aged; D008923:Missouri / Q000453:epidemiology; D011203:Poverty