Do Performance-based Health Measures Reflect Differences in Frailty Among Immigrants Age 50+ in Europe?

Background: Life course influences, including country of residence and country of birth, are associated with frailty index scores. We investigated these associations using performance-based health measures.
Methods: Among 33,745 participants age 50+ (mean age 64.8 ± 10.1; 55% women) in the Survey of Health, Ageing, and Retirement in Europe, grip strength, delayed word recall, and semantic verbal fluency were assessed. Participants were grouped by country of residence (Northern/Western Europe or Southern/Eastern Europe), and by country of birth (native-born, immigrants born in low- and middle-income countries [LMICs], or immigrants born in high-income countries [HICs]).
Results: Participants in Southern/Eastern Europe had lower mean test scores than those in Northern/Western Europe, and their scores did not differ by country of birth group. In Northern/Western Europe, compared with native-born participants, LMIC-born immigrants demonstrated lower mean grip strength (32.8 ± 7.6 kg vs. 35.7 ± 7.7 kg), delayed recall (2.9 ± 1.9 vs. 3.6 ± 1.9), and verbal fluency scores (16.0 ± 6.9 vs. 20.3 ± 7.0). HIC-born immigrants had mean scores higher than LMIC-born immigrants, but lower than native-born participants (all p<.001).
Conclusions: Cognitive and motor performance, measured from late middle age, were associated with national income levels of both country of residence and country of birth. This was similar to previously observed differences in frailty index scores.