Are left-behind families of migrant workers at increased risk of attempted suicide? – a cohort study of 178,000+ individuals in Sri Lanka

BACKGROUND: There are an estimated 258 million international migrants worldwide. In Asia low-skilled workers often emigrate on a temporary basis (2–3 years) without their families. There is significant concern over the mental health and wellbeing of left-behind families in this region. No previous study has examined whether the risk of suicidal behaviour is elevated in left-behind family members. METHODS: Cohort study using baseline data from a large randomised controlled trial in Sri Lanka (n = 178,730 participants; 8% households had a current temporary foreign migrant) and prospective hospital presentations of suicide attempts. Using multilevel Poisson regression models, we compared the risk of attempted suicide in households with left-behind and non-left-behind family members. We also investigated whether the sex of the migrant or the age/sex of the household member left behind altered any associations. RESULTS: The risk of an attempted suicide was elevated in female migrant households (IRR 1.60 95% CI 1.38, 1.85), but not male migrant households (IRR 1.01 95% CI 0.76,1.36)) with strong evidence that risk differed for female vs. male migrant households (p-value = 0.005). We found no evidence that the age or sex of the left-behind household member altered the association observed. CONCLUSIONS: This analysis suggests that members of households with a temporary female foreign migrant are at an increased risk of attempted suicide, but these findings must be interpreted with caution. The increased risk of suicidal behaviour in these households may be due to factors that were present before the migration and persist post-migration (e.g. household violence, poverty). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12888-018-2000-8) contains supplementary material, which is available to authorized users.