Injured Migrant Study (IMS): A prospective study of post-injury outcomes in New Zealand

Abstract

Background The burden of injury has been well documented, and migrants are more likely to have both higher risks of injury and experience poorer outcomes following injury compared to non-migrants. In New Zealand, a significant gap exists in the current literature concerning both the predictors of injury for migrants and the outcomes for migrants compared to non-migrants. To date, there is little known about long-term outcomes post-injury among migrants and most studies have focused on particular migrant sub-populations.

Aims The main aims of the Injured Migrant Study (IMS) are to investigate health and disability outcomes among migrants compared to non-migrants at 3-months and 24-months post-injury, and to identify predictors of poor health and disability outcomes for migrants at each time-point.

Methods This study used data from 2,850 participants in the Prospective Outcomes of Injury Study (POIS) undertaken in New Zealand. Participants, aged 18-64 years at the time of injury, were recruited via Accident Compensation Corporation (ACC) entitlement claims register between 2007 and 2009. Participants were classified as migrants if they were born overseas and as non-migrants if they were born in New Zealand. Data collected from interviews with participants at 3-months and 24-months post-injury were analysed, along with data collected from the National Minimum Dataset (NMDS) for those who were admitted to hospital or treated at an emergency department, for at least three hours, as a consequence of their injury, and data collected from ACC (about the injury itself). Health and disability outcomes for migrants compared to non-migrants, at each time-point, were quantified using Modified Poisson regression with robust standard errors. For migrants alone, various potential predictors were adjusted in separated models according to years living in New Zealand using the same regression method to identify predictors associated with poor health and disability outcomes.

Results Both migrants and non-migrants experienced similar proportions of poor outcomes post-injury. For example, at 3-months follow-up, 24% of migrants reported poor heath compared to 22% for non-migrants, and 45% had considerable disability compared to 42% of non-migrants. At 24-months post-injury, the proportion reporting poor health declined to 15% for migrants and 14% for non-migrants, while the proportion experiencing considerable disability was 13% among both groups. However, none of these post-injury proportions declined to the proportions experienced pre-injury.

Migrants had a 20% increased risk of reporting poor health and a 14% increased risk of disability at 3-months post-injury compared to non-migrants. This difference did not remain statistically significant at 24-months post-injury. For migrants, years living in New Zealand was not found to be associated with poor health or disability outcomes at either of the two time-points post-injury. Having poor health and inadequate household income pre-injury were strong predictors for poor health at both 3-months and 24-months post-injury among migrants. Additionally, perceiving the injury as a threat to their life at the time of the injury event was a predictor of poor health at 3-months, and living alone was a predictor of poor health at 24-months. Strong predictors of considerable disability at 3-months post-injury among migrants included: pre-injury disability, obesity, injury severity, and perceiving the injury as a threat of severe long-term disability; experiencing two or more chronic conditions pre-injury was only a predictor for migrants at 24-months post-injury.

Conclusions Poor health and disability were persistent for both migrants and non-migrants out to as long as two years following the injury event. However, migrants are more likely to experience poorer outcomes at 3-months post-injury compared to non-migrants. Certain predictors were associated with poor outcomes for migrants at each time-point. Future studies should explore why injured migrants, compared to non-migrants, in New Zealand are at higher risks of poor adverse outcomes following injury.