"Whose data is it anyway?" The implications of putting small area-level health and social data online.

Data from electronic patient management systems, routine national health databases, and social administrative systems have increased significantly over the past decade. These data are increasingly used to create maps and analyses communicating the geography of health and illness. The results of these analyses can be easily disseminated on the web often without due consideration for the identification, access, ethics, or governance, of these potentially sensitive data. Lack of consideration is currently proving a deterrent to many organisations that might otherwise provide data to central repositories for invaluable social science and medical research. We believe that exploitation of such data is needed to further our understanding of the determinants of health and inequalities. Therefore, we propose a geographical privacy-access continuum framework, which could guide data custodians in the efficient dissemination of data while retaining the confidentiality of the patients/individuals concerned. We conclude that a balance of restriction and access is needed allowing linkage of multiple datasets without disclosure, enabling researchers to gather the necessary evidence supporting policy changes or complex environmental and behavioural health interventions.