Effect of Relocation to the U.S. on Asthma Risk Among Hispanics

Abstract

Introduction: Asthma prevalence is reportedly higher among U.S.-born relative to foreign-born Hispanics/Latinos. Little is known about rates of asthma onset before and after relocation to the U.S. in Latinos. Asthma rates were examined by U.S. residence and country/territory of origin.

Methods: In 2015-2016, age at first onset of asthma symptoms was analyzed, defined retrospectively from a cross-sectional survey in 2008-2011, in relation to birthplace and U.S. residence among 15,573 U.S.-dwelling participants (aged 18-76 years) in the Hispanic Community Health Study/Study of Latinos.

Results: Cumulative incidence of asthma through age 30 years ranged from 7.9% among Mexican background individuals to 29.4% among those of Puerto Rican background. Among those born outside the U.S. mainland, the adjusted hazard for asthma was 1.52-fold higher (95% CI=1.25, 1.85) after relocation versus before relocation to the U.S. mainland, with heterogeneity in this association by Hispanic/Latino background (p-interaction<0.0001). Among foreign-born Dominicans and Mexicans, rates of asthma were greater after relocation versus before relocation (adjusted hazard ratio [AHR] for after versus before relocation, 2.42, 95% CI=1.44, 4.05 among Dominicans; AHR=2.90, 95% CI=2.02, 4.16 among Mexicans). Puerto Ricans had modestly increased asthma onset associated with U.S. mainland residence (AHR=1.52, 95% CI=1.06, 2.17). No similar increase associated with U.S. residence was observed among Central/South American immigrants (AHR=0.94, 95% CI=0.53, 1.67). Asthma rates among Cuban immigrants were lower after relocation (AHR=0.45, 95% CI=0.24, 0.82).

Conclusions: The effect of relocation to the U.S. on asthma risk among Hispanics is not uniform across Hispanic/Latino groups.

Figure 1

Age-specific trends in asthma incidence among U.S. Hispanic/Latino adults from diverse backgrounds, by birthplace and Hispanic/Latino background. Notes: Values are adjusted for age at interview. Age-specific immigration trends (right axis) illustrate the density of immigration at each age as a percentage of all foreign-born individuals in the target population.

Figure 2

Asthma risk through age 30 among U.S. Hispanic/Latino adults, by background and U.S. nativity/residence, as assessed retrospectively in 2008–2011 (n=15,344). Notes: Hazard ratios derived from Cox proportional hazards models adjusting for smoking status, age at interview, sex, educational attainment, second-hand exposure to tobacco smoke during childhood, and the complex survey design of HCHS/SOL; *p<0.05; **p<0.01; ***p<0.001. Heterogeneity in effect across Hispanic/Latino background groups significant at p<0.0001.