TY - Generic T1 - Interviewer variability in response rates in the Belgian Health Interview Survey Y1 - 2013 A1 - Johan Van der Heyden A1 - Stefaan Demarest A1 - Jean Tafforeau KW - 2004 KW - 2008 KW - adjustment KW - age KW - AGE GROUPS KW - Age-group KW - ALL KW - an KW - approach KW - approaches KW - Area KW - AS KW - Belgian KW - Belgium KW - CI KW - composition KW - Congresses KW - CONSUMPTION KW - CONTACT KW - Countries KW - Covariate KW - data KW - Database KW - education KW - effect KW - effects KW - epidemiology KW - European KW - Face KW - face-to-face KW - Failure KW - Fieldwork KW - Follow KW - Follow up KW - FOLLOW-UP KW - Gender KW - Group KW - health KW - health interview survey KW - health interview surveys KW - Health status KW - Health-status KW - HIS KW - household KW - households KW - Housing KW - Impact KW - improve KW - Increase KW - INFORMATION KW - Interview KW - Interview survey KW - IS KW - IT KW - LEVEL KW - Life KW - LIFE STYLE KW - life-style KW - Logistic KW - logistic regression KW - Logistic-regression KW - medical KW - medical consumption KW - MODEL KW - models KW - Motivation KW - multilevel KW - national KW - National Health Interview Survey KW - National-health KW - nationality KW - neighbourhood KW - Non response KW - Non-response KW - nonresponse KW - ODDS RATIO KW - older KW - ON KW - Participation KW - person KW - POPULATION KW - PROGRAM KW - Questionnaire KW - random KW - random-effects KW - RATES KW - Ratio KW - Ratios KW - recruitment KW - REFUSAL KW - Register KW - REGISTRIES KW - Registry KW - regression KW - Regression model KW - residence KW - response KW - response rate KW - response rates KW - result KW - results KW - Sample KW - sampling KW - sampling frame KW - Score KW - Secondary KW - SELECTED KW - self-administered KW - Self-administered questionnaire KW - sex KW - STANDARD KW - status KW - Strategies KW - Strategy KW - study KW - style KW - survey KW - surveys KW - training KW - Type KW - VARIABILITY KW - variables KW - variation KW - variations KW - WHO KW - young AB - In the Belgian HIS, information is gathered on the health status, life style and medical consumption of a representative sample of the population through a face to face interview and a self-administered questionnaire. The national population register is used as the sampling frame. Interviewers are recruited all over the country and have to pass through a standard training program. As in many other surveys unit non-reponse is an important concern. Compared to other national health interview surveys, unit non-response in the Belgian HIS is quite high. Moreover, it seems to increase. Between 1997 and 2008 the household refusal rate, calculated as the number of households who refused participation among those who were contacted, has risen from 39% to 45%. It is generally agreed that the motivation, training and follow up of the interviewers may have an important impact on the non-response. The impact of the interviewer on the response-rate can be explored by assessing to which extent response rates vary between interviewers after controlling for respondents' characteristics which may be related to non-response. The aim of this study was to verify if household's non-response varies significantly among interviewers and if there is a link between interviewer's characteristics and non-response. This was investigated separately for contact failure and refusal rate.Data were used from the HIS 2004, in which 10.013 households were selected for participation and 264 interviewers carried out the fieldwork. Information on age, sex and nationality of the household's reference person, household composition and place of residence was obtained from the national population registry. Information on the housing type and characteristics of the residential area was collected during the fieldwork. The household database was merged with data on the interviewer's gender, age and educational attainment. Non-reponse was explored by using multilevel logistic regression models with interviewer's characteristics as dependent variables, household characteristics as covariates and household's neighbourhood and interviewer as random effects. After adjustment for household characteristics and neighbourhood the proportion of non participating households is lower among interviewers belonging to the older age groups. Compared to the reference group of youngest interviewers (<45 years) the odds ratio for refusal is 0,67 (95% CI 0,60-0,75) for interviewers between 45 and 64 years and 0,46 (95% CI 0,35-0,61) for interviewers of 65+ years. The odds ratios for contact failure are respectively 0,69 (95% CI 0,59-0,81) and 0,62 (95% CI 0,41-0,92). Interviewers with tertiary education have significantly lower refusal rates than interviewers with only secondary education (OR 0,88; 95% CI 0,79-0,99). The variation of contact failure and refusal rates by interviewer remains significant after adjustment for household and interviewer characteristics.Our results indicate that in the Belgian HIS, non-response varies substantially among interviewers. Neither characteristics of the household, nor characteristics of the interviewer can explain this variation completely, but it is striking that older and high educated interviewers score better. If adjustment is made for characteristics that have an important impact on the response rate (such as the type of household, the neighbourhood, etc.) we would not expect large variations in response rate by interviewer. Large variations may indicate that there is a difference in the approach interviewers follow to contact the selected households and convince them to participate. The response rate in the Belgian HIS could probably be improved by putting more effort in the recruitment, training and follow up of interviewers, targeting specifically young interviewers and interviewers with a lower education level. Focusing the recruitment of interviewers on higher educated persons in the age groups above 45 years may also be a strategy to improve the response rate. JF - European Congress of Epidemiology CY - Aarhus CP - ? U1 - 35760 U2 - 15/07/2013 ER -