[Re-contact with immigrant workers in Spain through telephone interview (ITSAL II)]

Immigrants are recognized as a hard-to-reach-population. This study describes and assesses a three-year follow-up experience (final sample) with immigrant workers who participated in a survey three years earlier (initial sample), compares both samples and describes the final sample.

In 2008 a personal survey was carried out among 2434 immigrant workers (ITSAL I Project). Of these, 1229 had provided a telephone number allowing future recontact. In 2011, they were contacted for participation in a second project (ITSAL II Project). Outcome response rates of the American Association for Public Opinion Research were calculated. Sociodemographic and labour characteristics of workers of the initial and final samples were compared. In the final sample, sociodemographic and labour distribution of variables were compared by country of origin. Legal status, economic sector and occupation changes during this time were analyzed.

The proportion of those interviewed who fully answered the second interview (response rate) was 29.5%. The final sample had higher participation of Ecuadorians, women, persons older than 45 years and those with the highest education level. Romanian and Moroccan participants had the highest unemployment (45.1%, 40.0%). Overall, 71.1% did not change economic sector, and 63.2% improved their legal situation.

Our response rate is similar to those of similar studies. Re-contact was more difficult for some groups, depending on country of origin, age, education level and legal situation; for these, alternative means for followup should be sought out.