HARMONISING LOCAL HEALTH SURVEY DATA The EURALIM Experience

Previous chapters of this book have stressed the growing interest in continuously monitoring and comparing distributions of health determinants across populations to better inform public health workers and guide needed actions. Several authors have pointed to the need for a worldwide collection of survey data. We deal in this chapter with what appears to be a major paradox of global surveillance projects to date: data are currently available from many independent and locally based health studies, but the results cannot be directly compared across populations because of methodological variability. Our objective in this chapter is to demonstrate the importance and feasibility of a regional and eventually a global surveillance system to monitor the determinants of population health by pooling data from local surveys. We posit that the integration of existing systems will help ensure that surveillance data collected worldwide are more directly comparable across populations. This approach will also contribute to including those regions of the world that lack even the most basic surveillance infra-structure and resources (e.g., records of births and deaths). Its success depends on recognising and sharing expertise among all partners, the development of a core monitoring instrument, and co-ordinated efforts at fund-raising for central functions such as database maintenance. To date, three main techniques have been used to compare data across national and international studies, namely (1) centralised, standardised studies based on a uniform protocol, (2) meta-analyses of published-and sometimes unpublished-results, and