Mortality among internal and international migrants in the 100 Million Brazilian Cohort

• Published in: European journal of public health Vol. 32; no. Supplement_3
• Main Authors: Pescarini, JM, Goes, E, Scaff, P, Schindler, B, Rodrigues, LC, Brickley, EB, Smeeth, L, Barreto, ML
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 21-10-2022; Oxford Publishing Limited (England)
• Subjects: Age; Death; Death & dying; Disease; Health; Health promotion; Health risks; Internal migration; International migration; Maternal mortality; Mathematical analysis; Men; Migrants; Migration; Mortality; Mortality patterns; Mortality rates; Mortality risk; Populations; Public health; Regression analysis; Regression models; Risk; Sex; Women; Womens health; Brazil
• ISSN: 1101-1262; 1464-360X
• DOI: 10.1093/eurpub/ckac129.653

Background
There is limited evidence on the health of migrant populations in low and middle-income countries (LMICs). Here, we investigated the patterns of mortality risk in migrants and non-migrants in women and men over the life course.
Methods
We linked socioeconomic and mortality data from 1st Jan 2011 to 31st Dec 2018 in the 100 Million Brazilian Cohort. We calculated all-cause and cause-specific age-standardised mortality rates according to individuals' migration status. Using Cox regression models, we estimated the age- and sex-adjusted mortality hazard ratios (HR) for internal migrants (i.e., people born in Brazil but living in a different Brazilian state to their state of birth) compared to Brazilian-born non-migrants; and for international migrants (i.e., people born in another country) compared to Brazilian-born individuals.
Results
We followed 45,051,476 individuals, of whom 6,057,814 were internal migrants and 277,230 were international migrants. Internal migrants had a similar overall risk of all-cause mortality compared to Brazilian non-migrants (aHR=0.99, 95%CI=0.98-0.99), with lower mortality from some causes but higher mortality for some non-communicable diseases (NCDs). Compared to Brazilian-born individuals, international migrants had a lower risk of all-cause mortality (aHR=0.82, 95%CI=0.80-0.84), with up to 50% lower risk of death attributed to interpersonal violence among international migrant men (aHR=0.50, 95%CI=0.40-0.64), but a markedly higher risk of death by avoidable causes related to maternal health among young migrant women (aHR=2.17, 95%CI=1.17-4.05).
Conclusions
Overall, internal migration was not associated with excess all-cause mortality, while international migration into Brazil was associated with lower all-cause mortality. Mortality patterns among migrant populations in Brazil show marked variation for specific causes of death, and risks varied by age and sex.
Key messages
* Non-communicable diseases and maternal mortality are disproportionally higher among internal and international migrants, respectively.
* Further investigation of the underlying factors associated with higher maternal mortality among international migrant women is key to informing the targeting of social and health interventions.