From May 2003 to May 2006, the Robert Koch Institute conducted the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Nationwide data collection in 167 cities and municipalities was carried out by 4 survey teams, each consisting of a physician, centre interviewer, examiner, medical laboratory technician, environmental interviewer. Regional and seasonal factors were excluded by systematised route planning. Invitation of the participants and appointments for examinations were handled by a survey office with subsidised service telephone. Data processing in the survey office was performed using an SQL data base system programmed in the RKI. One central and several regional members of staff performing preparatory field visits were responsible for finding suitable examination rooms and for subject recruitment respectively. To further increase the response rate, continuous public relation actions were established. The survey involved questionnaires filled in by parents and parallel questionnaires for children from the age of 11 years onwards, physical examinations and tests and a computer assisted personal interview performed by the physician. The wide range of blood and urine testing carried out at central laboratories required standardised transport logistics. To achieve a high degree of standardisation of the survey, the examination teams were initially trained and then underwent continuous further training. The concept of quality management covered action of internal and independent external quality control monitoring each data collecting and data processing step as well as the training courses.
Conclusion: Dedicated public relations activities and the deployment of staff performing preparatory field visits increased the willingness of the subjects to participate. Intensive personnel care and continuous quality checks contribute to increased job satisfaction and data quality. By bindingly defining all laboratory diagnostic processes as well as transport logistics, high-quality laboratory test results are ensured. The conduct of the study from design via conduct to data processing and analysis by one institution guarantees complete control of all steps of the survey.