Participants’ recruitment: preliminary results of Portuguese National Health Examination Survey

Abstract publicado em: Eur J Public Health. 2015; 25(Suppl 3): 386. doi:10.1093/eurpub/ckv176.035. Disponível em: http://eurpub.oxfordjournals.org/content/eurpub/25/suppl_3/ckv176.035.full.pdfRecruitment of participants in health surveys is recognised as the most challenging step of fieldwork. This work presents preliminary results of recruitment in the first Portuguese National Health Examination Survey (INSEF) comparing participants and non participants. INSEF is a cross-sectional prevalence study targeting 4200 individuals aged 25–74 years, living in Portugal for more than 12 months, non-institutionalized and able to follow an interview in Portuguese. Fieldwork started in February 2015 and to date 9/49 examination sites are completed. Selected individuals received an invitation letter and later were contacted by phone to schedule the appointment. Individuals were then classified in participants, refusals and of unknown eligibility. Participation rates were calculated according to European Health Examination Survey guidelines. Reasons for refusals were recorded and non participant’s characteristics analysed. Chi square and Fisher exact tests were used to compare participants and non participants regarding age, sex, education level, marital status, smoking, use of medication and of healthcare services. 1467 of the 2161 selected individuals were successfully contacted. Overall participation rate was 42%(n = 882), ranging between 27–54% by examination site. 49% of the 512 refusals accepted to respond to a short questionnaire for non participants. The main reasons for non participation were lack of time (27.6%) and professional reasons (22.4%). No significant differences were found for the majority of the analysed variables. Participants were found to be more frequently users of medication (p < 0.001) and to have between 45–54 years old (p = 0.023). To date the planed participation rate of 40% was successfully achieved at national level. Results obtained showed the need to implement strategies to engage in participation specific target groups. To mitigate selection bias adjustment of sampling weights for non response should be done.The Portuguese National Health Examination Survey is developed as a part of the project “Improvement of epidemiological health information to support public health decision and management in Portugal. Towards reduced inequalities, improved health, and bilateral cooperation”, that benefits from a 1.500.000€ Grant from Iceland, Liechtenstein and Norway through the European Economic Area Grants (EEA Grants)