Table 1 Defining health inequity and disadvantage

Health inequalities have been defined as “the virtually universal phenomenon of variation in health indicators … associated with socio-economic status” [50]; inequities may also be seen across other characteristics such as place of residence, ethnicity, gender, etc. Health inequities “are unnecessary, avoidable, unfair, and remediable inequalities” [1, 51, 52]

The characteristics of populations and individuals across which health inequities may exist are multifactorial and may interact with each other. They may also depend on setting and context such as the political climate or health system [17]. Different classification systems have been developed to summarize these characteristics of individuals and populations across which potentially inequitable health differences may exist. Although different factors commonly co-exist, we are using the PROGRESS-Plus organizing framework used by the Cochrane and Campbell Equity Methods Group. The acronym PROGRESS represents: place of residence, race/ethnicity/culture/language, occupation, gender/sex, religion, education, socioeconomic status, and social capital [53, 54]. Additional “Plus” characteristics include (1) individual characteristics (e.g., age, disability), (2) features of relationships (e.g., parents who smoke), and (3) time-dependent transitions (e.g., post-discharge from hospital or prison) [54–56]. Differences in health across these groups do not necessarily denote inequities. For example, increasing cancer incidence with age is not necessarily unfair nor avoidable. However, preferential treatment for younger, fitter people with cancer may be discriminatory [57].

We use the term “disadvantaged” to describe populations who are denied opportunities that others have to benefit from social and environmental conditions that lead to better health. A limitation of the term disadvantaged is that it may be seen as labeling or stigmatizing and it is a term that may not be used by populations or communities to describe their contexts or situations. Many alternative terms are also limited (e.g., underserved or marginalized) because they exclude other population groups. Commitment to health equity is about improving health outcomes for people who have been disadvantaged by social, political, and legal structures, and processes in achieving good health.