The Cornella Health Interview Survey Follow-Up (CHIS.FU) Study: design, methods, and response rate
1 Cancer Prevention and Control Unit, Catalan Institute of Oncology, L'Hospitalet de Llobregat, Spain
2 Department of Methodology, University of Barcelona, Spain
3 Department of Public Health, University of Barcelona, Spain
4 Departmet of Public Health, Cornella de Llobregat City Council, Spain
5 Ministry of Health, Autonomous Government of Catalonia, Barcelona, Spain
6 Municipal Institute of Public Health, Barcelona, Spain
7 Department of Population Health Sciences, University of Wisconsin, United States
BMC Public Health 2003, 3:12 doi:10.1186/1471-2458-3-12Published: 7 March 2003
The aim of this report is to describe the main characteristics of the design, including response rates, of the Cornella Health Interview Survey Follow-up Study.
The original cohort consisted of 2,500 subjects (1,263 women and 1,237 men) interviewed as part of the 1994 Cornella Health Interview Study. A record linkage to update the address and vital status of the cohort members was carried out using, first a deterministic method, and secondly a probabilistic one, based on each subject's first name and surnames. Subsequently, we attempted to locate the cohort members to conduct the phone follow-up interviews. A pilot study was carried out to test the overall feasibility and to modify some procedures before the field work began.
After record linkage, 2,468 (98.7%) subjects were successfully traced. Of these, 91 (3.6%) were deceased, 259 (10.3%) had moved to other towns, and 50 (2.0%) had neither renewed their last municipal census documents nor declared having moved. After using different strategies to track and to retain cohort members, we traced 92% of the CHIS participants. From them, 1,605 subjects answered the follow-up questionnaire.
The computerized record linkage maximized the success of the follow-up that was carried out 7 years after the baseline interview. The pilot study was useful to increase the efficiency in tracing and interviewing the respondents.