Equality and equity are not synonyms. Equality involves considering individuals equally regardless of their circumstances, while equity involves adjusting the way individuals are considered based on their circumstances so that similar outcomes are achieved for everyone.

In health, both are important. For example, financial contributions to the health system should be equitable and low-income groups should not suffer from catastrophic health expenditure.

Access, on the other hand, should be equal: whoever needs to access services should have the right to do so, with the caveat that such need does exist.

Failure to build an equal and equitable health system leads to health disparities or inequities – differences in health and disease based on socioeconomic and geographic aspects.

Within the traditional health system context, equity and equality are considered along the lines of access, coverage and financing.

These three are interlinked – for example, inequitable financing may lead to lack of access, or inequitable coverage may lead to inequitable financing.

In terms of access, geography is often a major barrier for those in greatest need. In terms of financing, out-of-pocket expenditure may be a reason not to access consultation or treatment.

In terms of coverage, the design of health financing systems often excludes certain groups, for example employment-based insurance excluding the unemployed (who have increased risk of disease). 

Beyond this context, health disparities are also directly produced by non-health factors, such as socioeconomic status (e.g. mental health, employment), behaviour (e.g. culture and tradition, as well as socioeconomic status), geography (e.g. infrastructure, pollution) and education (e.g. health literacy).

These, and many others, are termed social determinants of health (SDoH) and emphasise why it is important for health to be framed holistically.