title: Colorectal cancer stage at diagnosis in migrants versus non-migrants (KoMigra): study protocol of a cross-sectional study in Germany.
abstract: BACKGROUND
  In Germany, about 20% of the total population have a migration background. Differences exist between migrants and non-migrants in terms of health care access and utilisation. Colorectal cancer is the second most common malignant tumour in Germany, and incidence, staging and survival chances depend, amongst other things, on ethnicity and lifestyle. The current study investigates whether stage at diagnosis differs between migrants and non-migrants with colorectal cancer in an area of high migration and attempts to identify factors that can explain any differences.
  
  
  METHODS
  Data on tumour and migration status will be collected for 1,200 consecutive patients that have received a new, histologically verified diagnosis of colorectal cancer in a high migration area in Germany in the previous three months. The recruitment process is expected to take 16 months and will include gastroenterological private practices and certified centres for intestinal diseases. Descriptive and analytical analysis will be performed: the distribution of variables for migrants versus non-migrants and participants versus non-participants will be analysed using appropriate χ2-, t-, F- or Wilcoxon tests. Multivariable, logistic regression models will be performed, with the dependent variable being the dichotomized stage of the tumour (UICC stage I versus more advanced than UICC stage I). Odds ratios and associated 95%-confidence intervals will be calculated. Furthermore, ordered logistic regression models will be estimated, with the exact stage of the tumour at diagnosis as the dependent variable. Predictors used in the ordered logistic regression will be patient characteristics that are specific to migrants as well as patient characteristics that are not. Interaction models will be estimated in order to investigate whether the effects of patient characteristics on stage of tumour at the time of the initial diagnosis is different in migrants, compared to non-migrants.
  
  
  CONCLUSIONS
  An association of migration status or other socioeconomic variables with stage at diagnosis of colorectal cancer would be an important finding with respect to equal health care access among migrants. It would point to access barriers or different symptom appraisal and, in the long term, could contribute to the development of new health care concepts for migrants.
  
  
  BACKGROUND
  German Clinical Trials Register DRKS00005056.
authors.affiliation: Institute of General Practice, Goethe-University Frankfurt, Frankfurt am Main, Germany. a.dahlhaus@dkfz-heidelberg.de.
authors.forename: Anne
authors.initials: A
authors.lastname: Dahlhaus
authors.forename: Corina
authors.initials: C
authors.lastname: Guethlin
authors.forename: Arthur
authors.initials: A
authors.lastname: Schall
authors.forename: Maja
authors.initials: M
authors.lastname: Taubenroth
authors.forename: Reyn
authors.initials: R
authors.lastname: van Ewijk
authors.forename: Hajo
authors.initials: H
authors.lastname: Zeeb
authors.forename: Zeycan
authors.initials: Z
authors.lastname: Albay
authors.forename: Sylvia
authors.initials: S
authors.lastname: Schulz-Rothe
authors.forename: Martin
authors.initials: M
authors.lastname: Beyer
authors.forename: Ferdinand M
authors.initials: FM
authors.lastname: Gerlach
authors.forename: Maria
authors.initials: M
authors.lastname: Blettner
authors.forename: Andrea
authors.initials: A
authors.lastname: Siebenhofer
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000208:ethnology*; D003430:Cross-Sectional Studies; D005260:Female; D005858:Germany / Q000208:ethnology; D006297:Health Services Accessibility / Q000191:economics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D014171:Transients and Migrants