From questionnaire to database: field work experience in the 'Immigration, work and health survey' (ITSAL Project)

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. Method: 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. (C) 2011 SESPAS. Published by Elsevier Espana, S.L. All rights reserved.