The Interaction Between Venous Thromboembolism and Socioeconomic Status on the Risk of Disability Pension.

BACKGROUND

Venous thromboembolism (VTE) is associated with increased risk of disability pension. How socioeconomic status (SES) impacts the risk of disability pension after a VTE is unknown. The aim of this nationwide population based cohort study to investigate the interaction between SES and incident VTE on the risk of subsequent disability pension.

METHODS

Using Danish national medical and administrative databases, we established a nationwide cohort of 41,781 individuals aged 25-65 years with incident VTE during 1995-2016 and a comparison cohort (n=208,905) from the general population matched on year of birth, sex, and calendar year of VTE. We computed incidence rates (IRs) as the number of disability pension events per 1000 person-years at risk and measured the interaction between VTE and levels of SES (high, medium, low) on an additive scale by calculating interaction contrasts (difference in IR difference).

RESULTS

Among individuals with high SES, the disability pension IR per 1000 person-years was 5.4 (95% CI: 4.8-6.1) in the VTE cohort and 1.6 (95% CI: 1.5-1.7) in the comparison cohort (IR difference 3.8). The corresponding disability pension IR in individuals with low SES was 55.1 (95% CI: 52.1-58.1) in the VTE cohort and 26.1 (95% CI: 25.1-27.1) in the comparison cohort (IR difference 24.0). An interaction contrast of 25.1 indicated that interaction accounted for 45.6% (25.1/55.1) of the disability pension IR in individuals with VTE and low SES.

CONCLUSION

SES and VTE interact to increase the risk of disability pension after VTE beyond their independent effects.