HIS - Health Interview Survey

The HIS is a cross-sectional population survey with a net sample of 10,000 participants. A stratified multi-stage, clustered sampling method is applied in which the regional numbers are fixed (3,500 participants each in the Flemish Region and the Walloon Region and 3,000 in the Brussels Region), with possible oversampling of certain groups. The National Register is used as a sampling framework. In each region a limited number of municipalities are selected, from which a limited number of households are then selected. A maximum of 4 members per household can participate in the interview. In order to take non-participation into account and to ensure the predetermined net sample size is achieved, non-participating households are replaced. 

The fieldwork is spread over a calendar year. First, the selected households receive an introductory letter and an information folder and then a trained interviewer visits the respondents’ homes to conduct the interview. Data collection is done using a Computer Assisted Personal Interview (CAPI). There is no age limit for participation, but a proxy interview is used for children under 15 years of age. The more sensitive data are collected using a self-administered questionnaire and should only be completed by respondents aged 15 and over.

The survey has been approved by the Data Protection Authority and has also received positive review from the Ethics Committee of Ghent University Hospital.

For more information on the sample and the fieldwork, see the HIS 2018 methodological report (Dutch version - French version).

• The study protocol describes the objectives, the scientific relevance, the methodology, the communication of results and reporting, the ethical aspects and the organization of the project.
• The questionnaires are available in Dutch, French, German and English. Since the HIS 2013, the face-to-face questionnaire has been administered via a computer (Computer Assisted Personal Interview — CAPI). The reference person or his/her partner answers the household level questionnaire each selected person (up to a maximum of 4 people per household) answers the  individual questionnaire that may be partly completed by a proxy. In addition, each selected person aged 15 years and over answers a  written questionnaire (also available in  French, Dutch and German that includes the generally more sensitive questions. This questionnaire cannot be completed by a proxy.

The HIS 2018 database includes data on health status, lifestyle, use of health services and socio-demographic characteristics of a representative sample of the Belgian population. The steps that have to be followed to query this database are described in detail in this procedure.