Health Equity

Health Equity as Fair Opportunity for Health and How Decision Makers Act on It

A health system that buys the most total health from its budget can still leave the gaps between richer and poorer groups unchanged or wider, and health equity is the principle used to judge which of those gaps are unfair and worth paying to close. In England, NICE and NHS England are now guided or required to weigh such gaps alongside total health. Economists turn the idea into a second decision objective through inequality aversion and distributional cost-effectiveness analysis, and an illustrative choice between two programmes shows how the trade-off works. Fairness in health care delivery and financing is covered on the page on equity, and the related terms Health Inequality, Health Inequity, Horizontal Equity and Vertical Equity each have their own entries.

Three definitions that shaped the term

One of the most widely cited definitions comes from Margaret Whitehead, in a discussion paper for the World Health Organization Regional Office for Europe published in the International Journal of Health Services in 1992. The working definition she set out, drawing on a 1985 WHO meeting, holds that equity in health means that ideally everyone should have a fair opportunity to attain their full health potential and, more pragmatically, that no one should be disadvantaged from achieving that potential if it can be avoided. On this view the policy aim is to reduce or remove the differences that result from factors judged both avoidable and unfair, which leaves room for some differences in health to remain.

Whitehead noted that differences arising from natural biological variation or freely chosen health-damaging behaviour would not normally be classified as inequities; her full sorting of the causes of health differences is set out in the Health Inequity entry.

Braveman and Gruskin later gave a definition designed for measurement, in which equity in health is the absence of systematic disparities in health, or in its major social determinants, between groups with different levels of underlying social advantage, meaning wealth, power or prestige. They link it to the right to the highest attainable standard of health. The World Health Organization's health topic page describes health equity as achieved when everyone can attain their full potential for health and well-being, and equity as the absence of unfair, avoidable or remediable differences among groups of people.

Other names for health equity, and terms that are not synonyms

People often search for another word for health equity. The closest equivalent in the literature is "equity in health", the form used by Whitehead and by Braveman and Gruskin, and "fair opportunity for health" is a restatement of Whitehead's central idea. Several nearby terms are not synonyms, and mixing them up changes what a claim means.

UK policy usage blurs the second row. The Marmot Review treats health inequalities as a matter of social justice, and the statutory duty described below is a duty to reduce them, so in these documents "health inequalities" usually means differences regarded as unfair. Whitehead noted the same ambiguity, in that some writers use the term to convey unfairness, others to mean unequal in a purely mathematical sense.

"Equitable health outcomes" should be read in the light of these distinctions. An equitable distribution is one in which the differences that remain between groups do not stem from avoidable disadvantage, so it can coexist with some variation in life expectancy.

From principle to decision objective

Standard cost-effectiveness analysis adds up health gains, usually in QALYs, and treats a QALY as worth the same whoever receives it. That rule pursues one objective, total health. Health equity adds a second, reducing unfair differences in health, and the DCEA tutorial by Asaria, Griffin and Cookson calls these the dual objectives of improving total population health and reducing unfair health inequality.

When the objectives conflict, a social welfare function states how much total health a decision maker would give up for a more equal distribution. A widely used form, based on the Atkinson index, expresses the result as equally distributed equivalent (EDE) health, defined as follows.

$$h_{EDE} = \left[ \frac{1}{n} \sum_{i=1}^{n} h_i^{\,1-\varepsilon} \right]^{\frac{1}{1-\varepsilon}}, \quad \varepsilon \neq 1$$

where $h_{EDE}$ is the level of health which, if everyone had it, would be judged as good as the actual distribution; $h_i$ is the health of person or group $i$ (for example, quality-adjusted life expectancy); $n$ is the number of people or equal-sized groups; and $\varepsilon$ is the inequality aversion parameter. When $\varepsilon = 0$ the EDE equals mean health, which is pure health maximisation. As $\varepsilon$ rises, gains to people in worse health count for more.

For small gains, the function implies that a gain to a group with health $h_i$ carries a weight of $(h_j / h_i)^{\varepsilon}$ relative to a gain to a group with health $h_j$. Robson and colleagues surveyed 244 members of the public in England online and found a median Atkinson parameter of 10.95, which at the levels of quality-adjusted life expectancy they used implies weighting gains to the poorest fifth six to seven times as highly as gains to the richest fifth. The DCEA tutorial treats the parameter as a social value judgement and varies it in sensitivity analysis.

Distributional cost-effectiveness analysis and equity weights

Distributional cost-effectiveness analysis is the framework NICE refers to in section 4.12 of its manual. It models the social distribution of health under each option, including whose health is displaced by the extra costs, and then judges those distributions against the dual objectives.

The tutorial's applied example on the NHS Bowel Cancer Screening Programme shows how much the value judgements matter. A universal reminder letter produced 1,000 more population QALYs than an enhanced reminder targeted at the most income-deprived areas and the areas with the highest proportion of residents from the Indian subcontinent, but the targeted reminder was preferred once the Atkinson parameter exceeded 8. The distribution of opportunity cost mattered too. At a parameter of 7, the ranking between the two reminder strategies favoured the universal one when all the opportunity cost fell on the least healthy subgroup, and reversed when it fell on the healthiest.

Equity-weighted analysis attaches explicit weights to health gains by group. A social welfare function implies such weights for small gains, although fixed weights do not adjust as each group's health changes, and both approaches are best reported alongside the unweighted result.

Worked example with two programmes and one budget

The figures in this example are illustrative. A health system can fund one of two programmes at the same cost. The population has two equal-sized groups, a more deprived group with a baseline quality-adjusted life expectancy of 60 years and a less deprived group with 70 years.

1. Compare total health. The mean gain per person is (0.6 + 1.0)/2 = 0.8 under A and (1.0 + 0.2)/2 = 0.6 under B. A health-maximising rule chooses A.

2. Compare the gap. The gap starts at 10 years. After A it is 71.0 − 60.6 = 10.4 years, so it widens. After B it is 70.2 − 61.0 = 9.2 years, so it narrows.

3. Find the equity weight at which the choice switches. If gains to the more deprived group carry weight $w$ and gains to the less deprived group carry weight 1, the weighted gain is $w \times 0.6 + 1.0$ under A and $w \times 1.0 + 0.2$ under B. Setting them equal gives the switching weight below.

$$w^{*} = \frac{1.0 - 0.2}{1.0 - 0.6} = \frac{0.8}{0.4} = 2$$

where $w^{*}$ is the switching weight. If a QALY gained by the more deprived group counts for more than twice a QALY gained by the less deprived group, B is preferred.

4. Translate the weight into inequality aversion. Using the Atkinson weights at baseline, the weight ratio is $(70/60)^{\varepsilon}$, so the switch occurs where that ratio equals 2 in the calculation below.

$$\varepsilon^{*} \approx \frac{\ln 2}{\ln (70/60)} = \frac{0.6931}{0.1542} \approx 4.5$$

where $\varepsilon^{*}$ is the approximate switching value of the inequality aversion parameter and $\ln$ is the natural logarithm. Calculating EDE health exactly, which lets the weights change as health changes, puts the switch at about 4.6. At the English public estimate of 10.95, EDE health is about 63.97 years under B and 63.76 years under A, so B is preferred.

5. Allow for displaced health. Because the two programmes cost the same, the health displaced elsewhere in the system is the same under A and B, so it does not change the health-maximising choice. Where it falls changes the switching value. If the displaced health amounts to 1.0 year for each member of the more deprived group, the exact switch falls from about 4.6 to about 4.2, favouring B further; if the same loss falls on the less deprived group, the switch rises to about 5.1. B is still preferred at 10.95 in both cases.

6. Interpret the result. A gives more total health and B a fairer distribution, and the choice turns on an explicit judgement about inequality aversion. A report of this analysis would show the unweighted result, the switching values and the assumption about who bears the displaced health.

How NICE and the NHS act on health inequalities

In England, health equity enters decisions through appraisal methods and statutory duties. The NICE technology appraisal and highly specialised technologies manual (PMG36) gives all QALYs equal weight in its reference case (section 6.2.10), and in May 2025 it added guidance on evidence about health inequalities. The equity page gives the fuller account; the main points for health technology assessment are these.

• If robust evidence shows a substantial effect on health inequalities, the committee considers it in judging whether the technology is an effective use of NHS resources, and it can apply flexibility to the range normally considered cost effective, taking account of displacement and opportunity cost (sections 6.2.35 and 6.2.38).
• A company should include a distributional cost-effectiveness analysis only when there is clear evidence of a significant burden of health inequalities in the eligible population, and the analysis should not weigh costs or benefits differently by social characteristics (sections 4.12.2 and 4.12.7).
• Health inequalities are among the factors the committee specifically considers when the most plausible ICER is above £25,000 per QALY gained, or £100,000 per QALY gained for highly specialised technologies (section 6.3.5).

Outside appraisal, section 13G of the National Health Service Act 2006, inserted by the Health and Social Care Act 2012, requires NHS England to have regard to the need to reduce inequalities between patients in their ability to access health services and in the outcomes achieved for them by the provision of health services. NHS England's adult Core20PLUS5 approach targets the most deprived 20% of the national population by the Index of Multiple Deprivation, plus groups chosen by integrated care systems that have poorer than average access, experience or outcomes, across five clinical areas, namely maternity, severe mental illness, chronic respiratory disease, early cancer diagnosis, and hypertension case-finding and optimal management together with lipid optimal management. A separate version for children and young people, published in November 2022, covers asthma, diabetes, epilepsy, oral health and mental health. The Marmot Review of 2010 described proportionate universalism, in which action is universal but with a scale and intensity proportionate to the level of disadvantage, on the grounds that focusing only on the most disadvantaged would not reduce the social gradient in health.

Where health equity is misread

The most common error is to treat health equity as equal health for everyone, which the Whitehead definition rules out. A related error is to call every measured difference an inequity, since data can show a gap, but calling it an inequity needs a judgement about its cause and fairness.

In economic evaluation, giving every QALY the same weight is sometimes treated as value-free, but it corresponds to an inequality aversion of zero and is itself a distributional judgement. A single elicited parameter such as 10.95 comes from one survey in one country, and rankings can change across the plausible range. NICE also keeps health inequality analysis separate from its obligations under the Equality Act 2010 (section 6.2.36), so meeting one does not establish the other.

Sources

• Asaria M, Griffin S, Cookson R. Distributional cost-effectiveness analysis: a tutorial. Medical Decision Making. 2016;36(1):8-19. https://pmc.ncbi.nlm.nih.gov/articles/PMC4853814/
• Braveman P, Gruskin S. Defining equity in health. Journal of Epidemiology and Community Health. 2003;57(4):254-258. https://pmc.ncbi.nlm.nih.gov/articles/PMC1732430/
• Marmot M, Goldblatt P, Allen J, et al. Fair Society, Healthy Lives: The Marmot Review. Strategic Review of Health Inequalities in England post-2010. London: The Marmot Review; 2010.
• National Health Service Act 2006, section 13G (Duty as to reducing inequalities), inserted by the Health and Social Care Act 2012. https://www.legislation.gov.uk/ukpga/2006/41/section/13G
• National Institute for Health and Care Excellence. NICE technology appraisal and highly specialised technologies guidance: the manual (PMG36). Published 31 January 2022, last updated 13 October 2026. Sections 4.12, 6.2.10, 6.2.35 to 6.2.38 and 6.3.5.
• NHS England. Core20PLUS5 (adults): an approach to reducing healthcare inequalities. Web page, with the Core20PLUS5 infographic (2021). https://www.england.nhs.uk/about/equality/equality-hub/national-healthcare-inequalities-improvement-programme/core20plus5/
• NHS England. Core20PLUS5 infographic: children and young people. Published 18 November 2022. https://www.england.nhs.uk/long-read/core20plus5-infographic-children-and-young-people/
• Robson M, Asaria M, Cookson R, Tsuchiya A, Ali S. Eliciting the level of health inequality aversion in England. Health Economics. 2017;26(10):1328-1334. https://pmc.ncbi.nlm.nih.gov/articles/PMC6120144/
• Whitehead M. The concepts and principles of equity and health. International Journal of Health Services. 1992;22(3):429-445. Originally a discussion paper for the World Health Organization Regional Office for Europe (EUR/ICP/RPD 414), Copenhagen, 1990.
• World Health Organization. Health equity (health topic page). Accessed 1 October 2026. https://www.who.int/health-topics/health-equity