What is the prevalence and impact of frailty in minority ethnic populations?

Problem

Few studies have examined the prevalence and associated mortality of frailty among ethnic minorities in the UK. Better understanding of ethnic mortality differentials can inform policy relating to health inequalities. We aimed to describe the distribution and odds of frailty and its associated mortality across ethnic groups in UK Biobank.

Approach

A prospective cohort; 502,643 participants aged 37-73 years; self-reported demographics/health/lifestyle data; linked to registries to ascertain deaths. Ethnicity groups: White British, Other-White background, White Irish, Asian/Asian British, Black/Black British, Other, Mixed, or Chinese. Frailty assessed by 5 criteria (Frailty Phenotype): grip strength/walking-speed/exhaustion/weight-loss/physical activity. Participants considered ‘frail’ if they met ≥3 criteria; ‘pre-frail’ if they met 1-2 criteria; and ‘not frail’ if no criteria met.Frailty prevalence was stratified by sex and age. Multinomial logistic regression models used to estimate likelihood for frailty, adjusting for demographics and lifestyle. Cox proportional hazards models used to examine associations between frailty and all-cause mortality.

Findings

485,490 participants had complete data; 17,153 (3.4%) with missing data excluded. Minority ethnic groups were under-represented compared to UK general population: 431,416 (88.9%) White British; 15,860 (3.3%) Other-White background; 12,767 (2.6%) White Irish; 9,124 (1.9%) Asian or Asian British; 7,673 (1.6%) Black or Black British; 4,275 (0.9%) Other ethnicity; 2,862 (0.6%) Mixed ethnicity; and 1,513 (0.3%) Chinese. Compared to White British, minority ethnic groups had more females, were younger, more deprived, smoked less, and drank alcohol less often. After 108.2 months (IQR 17.3) median follow up there were 18,965 (3.9%) deaths.Frailty prevalence (unadjusted) was higher in most minority ethnic groups for nearly all age-sex groups. In those aged 56-65, frailty prevalence was highest in Asian/Asian British women (15.3%) and in Asian/Asian British men (11.0%). Equivalent figures for White British were 4.0% for women and 3.0% for men. White British men and Other-White background women had the lowest prevalence of frailty. Compared to White British participants, adjusted ORs (95%CI) for frailty were significantly higher for nearly all ethnic minorities: White Irish 1.28 (1.16-1.41); Asian/Asian British 4.40 (4.04-4.79); Black/Black British 1.71 (1.55-1.89); Chinese 2.33 (1.78-3.05); Mixed 1.23 (1.01-1.48); and Other 2.65 (2.34-3.00). However, compared to White British, there were significantly lower mortality hazards associated with frailty in Asian/Asian British and Black/Black British: HR (95%CI) 0.54 (0.41-0.72); and 0.59 (0.40-0.87), respectively. For all other ethnic minorities, frailty mortality associations were not significantly different from those of White British.

Consequences

Prevalence of frailty was higher in ethnic minorities than in White British. After adjusting for sociodemographic and lifestyle factors, odds of being frail remained significantly higher in ethnic minorities. However, frailty was associated with lower or similar mortality compared to White British participants. Developing an understanding of how frailty impacts different ethnic groups could help improve health equity.