Mortality in migrants with dementia living in Lazio, Italy: A 5-year cohort study

Background: Alzheimer's disease and other dementias are major causes of disability and death among older adults. With an increasing number of older migrants in Italy, dementia prevalence in this group is expected to rise. However, little is known about their health outcomes. Objective: This study aimed to analyze mortality in migrants with dementia in Lazio, Italy, as part of the ImmiDem project (GR-2021-12372081). Methods: A cohort study was conducted on individuals aged ≥50 with dementia living in Lazio as of December 31, 2018, who were followed for 5 years. Migratory status was defined by country of birth: native Italians, migrants from High Migratory Pressure Countries (HMPCs), or Highly Developed Countries (HDCs). Age-standardized mortality proportion was calculated by migratory status, and time-to-event analysis was performed using Cox regression models. Results: As of December 31, 2018, 38,380 individuals with dementia lived in Lazio, with 2.1% born in HMPCs and 0.9% in HDCs. The age-standardized mortality proportion was lower in migrants born in HPMCs (30.7%; 95% CI: 26.4–35.8) than among natives (36.8%; 95% CI: 35.4–38.4). The age- and sex-adjusted hazard ratio (HR) confirmed lower mortality in migrants (HMPCs HR = 0.91, 95% CI:0.82–1; HDCs HR = 0.79, 95% CI:0.68–0.91) than natives. Conclusions: Migrants with dementia showed lower mortality than Italians, possibly due to health advantages, salmon bias, or migration dynamics. However, these findings may not accurately reflect better health status. Potential underdiagnosis of dementia and the use of country of birth as a proxy for migratory status may have influenced results and should be considered in future research.