Standardization of physical measurements in European health examination surveys - Experiences from the site visits

Background Health examination surveys (HESs) provide valuable data on health and its determinants at the population level. Comparison of HES results within and between countries and over time requires measurements which are free of bias due to differences in or adherence to measurement procedures and/or measurement devices. Methods In the European HES (EHES) Pilot Project, 12 countries conducted a pilot HES in 2010-11 using standardized measurement protocols and centralized training. External evaluation visits (site visits) were performed by the EHES Reference Centre staff to evaluate the success of standardization and quality of data collection. Results In general, standardized EHES protocols were followed adequately in all the pilot surveys. Small deviations were observed in the posture of participants during the blood pressure and height measurement; in the use of a tourniquet when drawing blood samples; and in the calibration of measurement devices. Occasionally, problems with disturbing noise from outside or people coming into the room during the measurements were observed. In countries with an ongoing national HES or a long tradition of conducting national HESs at regular intervals, it was more difficult to modify national protocols to fulfil EHES requirements. Conclusions The EHES protocols to standardize HES measurements and procedures for collection of blood samples are feasible in cross-country settings. The prerequisite for successful standardization is adequate training. External and internal evaluation activities during the survey fieldwork are also needed to monitor compliance to standards.