title: From questionnaire to database: field work experience in the 'Immigration, work and health survey' (ITSAL Project).
abstract: OBJECTIVE
  Despite the need for information in the area of migration and health, the available data are sparse. We describe the field work in a cross-sectional study on the health of immigrant workers in Spain.
  
  
  METHODS
  A convenience sample of workers from Colombia, Ecuador, Morocco and Rumania in four cities was targeted, using a block-walking approach. The outcome rates of the American Association of Public Opinion Research were estimated.
  
  
  RESULTS
  Of 6,504 persons approached, 71.4% were eligible contacts. Of these contacts, only 57.8% completed interviews. Response and cooperation rates were above 50%.
  
  
  CONCLUSIONS
  Block-walking enabled surveyors to access difficult-to-reach groups. The use of specifically trained surveyors with a background similar to that of the target population increased the effectiveness of our methods.
authors.affiliation: Center for Research in Occupational Health, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, Spain.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Delclos
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Benavides
authors.forename: Ana M
authors.initials: AM
authors.lastname: García
authors.forename: María José
authors.initials: MJ
authors.lastname: López-Jacob
authors.forename: Elena
authors.initials: E
authors.lastname: Ronda
mesh_terms: D000328:Adult; D003105:Colombia / Q000208:ethnology; D003144:Communication Barriers; D003430:Cross-Sectional Studies; D003625:Data Collection / Q000379:methods; D016208:Databases, Factual; D004484:Ecuador / Q000208:ethnology; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D004641:Emigration and Immigration; D004651:Employment; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D009018:Morocco / Q000208:ethnology; D012383:Romania / Q000208:ethnology; D012494:Sampling Studies; D013030:Spain; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data; D055815:Young Adult