Aspects of the fieldwork in the National Nutrition Survey II (NVS II)

C. Cholmakow-Bodechtel, H. Mühlbauer, U. Reis, F. Reiter, Ch. Brombach, Munich, Karlsruhe

Behind every study, including NVS II, there is fieldwork providing the necessary information about the sample to be analyzed. In the case of NVS II, field work is carried out by the market research company TNS Healthcare Ltd. in Munich. The present article is to give an impression of the practical work involved and of the kind of organisation necessary for a study of such dimension.

For NVS II, 500 sample points in Germany were randomly chosen. Local register offices were asked for a certain amount of addresses of participants between 14 and 80 years of age, not living in institutions. These addresses have to be representative of the structure of the respective community. For every sample point, route plans are designed. For every wave (three months), sample points are divided into statistical Nielsen areas. Route plans are to ensure that the teams need not drive too much and that double interviews are avoided.

To obtain a representative set of data concerning food intake and nutritional patterns of about 20,000 persons in one year of field work (November 2005 until November 2006), TNS Healthcare recruited 35 field workers. Eight teams comprising a contact person (“contacter”) and three interviewers are touring Germany to collect the necessary data. The contacter arrives three days earlier at the sample point than the team. He/she contacts all those participants who did not respond to the invitation, looks after the study centre close to the places where the participants live to make sure everything is o.k. and, finally, contacts the local municipality and the local press.

When the contact person has left for the next sample point, the team arrives. Three days are reserved for interviews at each sample point. The study centre is regularly open 12 hours per day including late evening hours. The interviewers also visit participants at home if they are not able to come to the study centre. In personal interviews, the usual nutrition patterns are analysed and body measurements recorded. Interviewers also inform participants about the phone interviews following and about the weighing protocol and they help in completing the questionnaires.

Invitations, reminders and data obtained from the field are managed by an Access Databank at the Munich headquarter which is also responsible for details such as leasing of study centres, contacts to local authorities and press, materials required (e. g. questionnaires, photo books, addresses, protocols) and support to the field teams. After one year of field work, the eight teams will have covered a distance corresponding to thirteen tours around the world. About 4500 kg of material will have been mailed.

Key words: National Nutrition Survey II (NVS II) / fieldwork

Sie finden den Artikel in deutscher Sprache in Ernährungs-Umschau 07/06 ab Seite 256.