Equity & Diversity in Evidence

An equity lens asks whether a study’s findings hold across the groups who present to your ED, not just the population that happened to be enrolled. Trials routinely under-represent women, older and multimorbid patients, ethnic minorities, pregnant people and socioeconomically deprived groups — limiting applicability and risking inequity. The PROGRESS-Plus framework lists the factors (Place, Race/ethnicity, Occupation, Gender/sex, Religion, Education, Socioeconomic status, Social capital — plus age, disability and others) that stratify health.

A trial recruits a narrow slice of patients, then its result is pushed onto everyone. For patients like those studied the evidence is sound; for under-represented groups — older, comorbid, minority, pregnant, deprived — applicability is uncertain and must be judged, not assumed.

Three questions hang off the lower branch. Could the effect differ in this group (effect modification)? Could access to the intervention differ (cost, mobility, language)? Do the outcomes measured matter equally to them? If any answer is “maybe”, the headline result does not transfer cleanly.

Evidence-based medicine that ignores who was studied can entrench inequity: the best-supported treatments accumulate around the best-studied (often advantaged) groups, while others are treated on extrapolation. Appraising equity protects external validity and fairness — both are examined in FRCEM.

• PROGRESS-Plus = the checklist of equity-relevant factors
• Ask: differential effect, differential access, do outcomes matter equally?
• Under-representation limits external validity for groups not enrolled

The case-mix gap — a landmark ED intervention trial enrols a relatively young, fit, single-pathology cohort with few language or social barriers. Your next shift is older, frailer and multimorbid, with several patients who do not speak English as a first language. The trial’s average effect is real, but the people in front of you sit on the under-studied branch — so the size, and even direction, of benefit for them is genuinely uncertain. Under-representation is not a footnote: a result can be internally valid yet simply untested in the very patients your department sees most.

• Treating under-representation as a minor caveat rather than a real limit on applicability.
• Assuming a uniform effect across groups when effect modification is plausible.
• Overlooking how an “effective” intervention can widen inequities through unequal access.