[Facilitators of participation and implementation of the immigrant families' PELFI Sub-Cohort].

Objective: PELFI is a multicentre cohort study of migrant families in Spain. The objectives of this manuscript were: 1) to describe the recruitment strategies, data collection and the main socio-demographic characteristics according to geographical origin and sex of participants of the families; and 2) to assess the recruitment and data collection strategies that facilitated participation in the basal assessment of the Badalona and Santa Coloma de Gramanet cohort.

Method: Descriptive study on a convenience sample of migrant and native families residing in Badalona and Santa Coloma de Gramanet.

[PELFI Project: Recruitment and Sociodemographic Characteristics of Immigrant and Autochthonous Families from Alicante and Barcelona City Subcohorts].

This study is a part of the multi-centre project "Platform of Longitudinal Studies of Immigrant Families (PELFI)" of the Immigration and Health Subprogram of the CIBER-ESP. It describes the field work and data collection of two sub-cohorts of immigrant and native families, and their main socio-demographic characteristics. Prospective observational cohort study in carried out in Barcelona and Alicante, Spain.