Frailty and migration in middle-aged and older Europeans

We evaluated life course influences on health by investigating potential differences in levels of frailty between middle-aged and older European immigrants born in low- and middle-income countries (LMICs), immigrants born in high income countries (HICs), and their native-born European peers. Using data from the Survey of Health, Ageing, and Retirement in Europe (SHARE), we constructed a frailty index from 70 age-related health measures for 33,745 participants aged 50+ (mean=64.9 ± 10.2 years; 54% women) in 14 European countries. Participants were grouped as native-born or as immigrants born in LMICs or in HICs, and further by current residence in Northern/Western or Southern/Eastern Europe. Seven percent of participants (n=2369) were immigrants (mean=64.4 ± 10.2 years; 56% women; LMIC-born=3.4%, HIC-born=3.6%). In Northern/Western Europe, after adjustment for age, gender, and education, LMIC-born immigrants demonstrated higher frailty index scores (mean=0.18, 95% confidence interval=0.17-0.19) than both HIC-born immigrants (0.16, 0.16-0.17) and native-born participants (0.15, 0.14-0.15 both p<0.001). In Southern/Eastern Europe, frailty index scores did not differ between groups (p=0.2). Time since migration explained significant variance in frailty index scores only in HIC-born immigrants to Southern/Eastern Europe (4.3%, p=0.03). Despite differences in frailty, survival did not differ between groups (p=0.2). LMIC-born immigrants demonstrated higher levels of frailty in Northern/Western Europe, but not Southern/Eastern Europe. Country of birth and current country of residence were each associated with frailty. Life course influences are demonstrable, but complex.