National Health Examination Surveys: an essential piece of the health planning puzzle.

National health examination surveys (HESs) have been developed to provide important information that cannot be obtained from other sources. A HES combines information obtained by asking participants questions with biophysical measurements taken by trained field staff. They are observational studies with the highest external validity and make specific contributions to both population (public health) and individual health. Few countries have a track record of a regular wide-ranging HES, but these are the basis of many reports and scientific papers. Despite this, little evidence about HES usefulness and impact or the factors that influence HES effectiveness have been disseminated. This paper presents examples of HES contributions to society in both Europe and the Americas. We sought information by emailing a wide list of people involved in running or using national HESs across Europe and the Americas. We asked for examples of where examination data from their HES had been used in national or regional policymaking. We found multiple examples of HES data being used for agenda-setting, including by highlighting nutritional needs and identifying underdiagnosis and poor management of certain conditions. We also found many ways in which HES have been used to monitor the impact of policies and define population norms. HES data have also been used in policy formation and implementation. HES data are influential and powerful. There is need for global support, financing and networking to transfer capacities and innovation in both fieldwork and laboratory technology.