Applying clinical epidemiological methods to health equity: the equity effectiveness loop

Abstract

Focusing on the average effects of interventions on health may miss important differences within populations. Examining these effects across gradients in wealth allows the identification of the interventions most likely to reduce health inequalities

Fig 1

Equity effectiveness loop

Fig 2

Mortality under age 5 by wealth quintiles across a small rural area in a setting where malaria is endemic⁵⁴

Fig 3

Prevalence of arthritis by wealth in Canada (as an example of an industrialised country)

Fig 4

Staircase effect of increasing gap and decreasing effectiveness across four factors, illustrated by using hypothetical estimates for total joint arthroplasty. As efficacy is multiplied by each of the four modifiers of access, diagnostic accuracy, provider compliance, and consumer adherence, the staircase effect causes decreasing community effectiveness and increasing relative gap between poorest and least poor from zero gap in “ideal” efficacy conditions to a ratio of least poor to poorest in “real life” of 1.6 (shown in the table)