This project aims to evaluate the influence of patterns of primary care contact on ED visits and potentially preventable hospitalisations for patients with a range of national priority chronic complex conditions, including diabetes, congestive heart failure, chronic obstructive pulmonary disease and asthma. The project uses a range of administrative data collections from NSW linked to the 45 and Up Study Cohort, and will make comparisons with Commonwealth data and data from Western Australia (no linkage of 45 and Up Study data or NSW Administrative data to these collections will occur).