These definitions are intended to be operational definitions; that is, they are designed to facilitate the development of specific measures to assess their attainment, on the assumption that it does no good to provide a definition if it does not facilitate assessment of change or the extent to which a goal has been reached. For example, most definitions of equity use the terms “fairness” or “just”, but these characteristics seem to defy measurement. This is why the definitions may be quite different from those you are accustomed to seeing or have encountered. The concepts defined herein are ones that either have no well accepted definitions or have definitions that have not proved useful either in informing my own research or in interpreting the literature. They derive from my experiences in designing research and trying to glean useful ideas from a diverse set of readings. Although the definitions are not likely to be readily accepted by everyone who considers them, the intent is to generate discussion so that research may move ahead with better conceptualisation of research topics and variables and more consistent interpretation of research findings. #### Access and use (1) : Accessibility (of health services): aspects of the structure of health services or health facilities that enhance the ability of people to reach a health care practitioner, in terms of location, time, and ease of approach. (2) : Access (to health services): the perceptions and experiences of people as to their ease in reaching health services or health facilities in terms of location, time, and ease of approach. (3) : Utilisation/use (of health services): experience of people as to their receipt of health care services of different types. C hronic disease, illness, or condition: a disease, illness, or condition that increases the risk of long term disability, handicap, or death and is unlikely to remit, although the occurrence and/or severity of its manifestations may vary over time. The distinction between a chronic illness and a non-chronic illness is generally made according to the likelihood of its lasting for 12 months or more and resulting in functional limitations and/or need for ongoing medical care.1 Data from population-based studies of visits to medical facilities show that people with a “diagnosed” chronic illness often do not have that diagnosis from year to year, and people who have one or …