TY - JOUR

T1 - Incidence of stroke, transient ischaemic attack and determinants of poststroke mortality among immigrants in Denmark, 2004-2018

T2 - A population-based cohort study

AU - Mkoma, George Frederick

AU - Johnsen, Søren Paaske

AU - Iversen, Helle Klingenberg

AU - Andersen, Grethe

AU - Norredam, Marie

N1 - Publisher Copyright: © Authors 2021

PY - 2021

Y1 - 2021

N2 - Objective Using recent registry data, we aimed to quantify the incidence of stroke and transient ischaemic attack (TIA) and to examine factors influencing the risk of poststroke mortality among immigrants compared with Danish-born individuals. Design Population-based cohort study between 2004 and 2018. We estimated age-standardised incidence rate ratios (IRR) of stroke, stroke types and TIA for each ethnic group using Danish-born individuals as the reference by direct method of standardisation. We calculated the risk of poststroke mortality using Cox proportional hazard regression. Setting The study was conducted using Danish nationwide registers. Participants All cases of first-ever stroke and TIA by country of origin (n=132 936) were included. Results Overall, Western immigrants (IRR=2.25; 95% CI 2.20 to 2.31) and non-Western immigrants (IRR=1.37; 95% CI 1.30 to 1.44) had a higher risk of stroke than Danish-born individuals. The risk of TIA was higher in Western immigrants (IRR=2.08; 95% CI 1.93 to 2.23) followed by non-Western immigrants (IRR=1.45; 95% CI 1.27 to 1.63) than in Danish-born individuals. All-cause 1-year mortality hazard was higher but not significantly different in non-Western men (adjusted HR=1.38; 95% CI 0.92 to 2.08) compared with Danish-born men and additional adjustment for comorbidities reduced the HR to 0.85 (0.51 to 1.40) among ischaemic stroke cases. Among intracerebral haemorrhage cases, the adjusted mortality hazard was decreased in Western men (from HR of 1.76; 95% CI 1.09 to 2.85 to HR of 1.30; 95% CI 0.80 to 2.11) compared with Danish-born men after adjustment for stroke severity. Immigrants with ≤15 years of residence had a lower poststroke mortality hazard than Danish-born individuals after additional adjustment for sociodemographic factors (HR=0.36; 95% CI 0.14 to 0.91). Conclusions The age-standardised risk of stroke and TIA was significantly higher among the majority of immigrants than Danish-born individuals. Interventions that reduce the burden of comorbidities, improve acute stroke care and target sociodemographic factors may address the higher risk of poststroke mortality among immigrants.

AB - Objective Using recent registry data, we aimed to quantify the incidence of stroke and transient ischaemic attack (TIA) and to examine factors influencing the risk of poststroke mortality among immigrants compared with Danish-born individuals. Design Population-based cohort study between 2004 and 2018. We estimated age-standardised incidence rate ratios (IRR) of stroke, stroke types and TIA for each ethnic group using Danish-born individuals as the reference by direct method of standardisation. We calculated the risk of poststroke mortality using Cox proportional hazard regression. Setting The study was conducted using Danish nationwide registers. Participants All cases of first-ever stroke and TIA by country of origin (n=132 936) were included. Results Overall, Western immigrants (IRR=2.25; 95% CI 2.20 to 2.31) and non-Western immigrants (IRR=1.37; 95% CI 1.30 to 1.44) had a higher risk of stroke than Danish-born individuals. The risk of TIA was higher in Western immigrants (IRR=2.08; 95% CI 1.93 to 2.23) followed by non-Western immigrants (IRR=1.45; 95% CI 1.27 to 1.63) than in Danish-born individuals. All-cause 1-year mortality hazard was higher but not significantly different in non-Western men (adjusted HR=1.38; 95% CI 0.92 to 2.08) compared with Danish-born men and additional adjustment for comorbidities reduced the HR to 0.85 (0.51 to 1.40) among ischaemic stroke cases. Among intracerebral haemorrhage cases, the adjusted mortality hazard was decreased in Western men (from HR of 1.76; 95% CI 1.09 to 2.85 to HR of 1.30; 95% CI 0.80 to 2.11) compared with Danish-born men after adjustment for stroke severity. Immigrants with ≤15 years of residence had a lower poststroke mortality hazard than Danish-born individuals after additional adjustment for sociodemographic factors (HR=0.36; 95% CI 0.14 to 0.91). Conclusions The age-standardised risk of stroke and TIA was significantly higher among the majority of immigrants than Danish-born individuals. Interventions that reduce the burden of comorbidities, improve acute stroke care and target sociodemographic factors may address the higher risk of poststroke mortality among immigrants.

KW - epidemiology

KW - public health

KW - stroke

U2 - 10.1136/bmjopen-2021-049347

DO - 10.1136/bmjopen-2021-049347

M3 - Journal article

C2 - 34675015

AN - SCOPUS:85118307740

VL - 11

JO - BMJ Open

JF - BMJ Open

SN - 2044-6055

IS - 10

M1 - e049347

ER -