Association between annual household income and adverse outcomes in patients who had ischaemic stroke

Abstract

Background and purpose: The association between annual household income and prognosis of ischaemic stroke remains debatable. We aimed to prospectively investigate the relationship between annual household income and prognosis at 3 months after ischaemic stroke.

Methods: We included 3975 participants from the China Antihypertensive Trial in Acute Ischemic Stroke. All participants were categorised into three groups according to annual household income per capita: <¥10 000 (Chinese Yuan Renminbi (RMB)), ¥10 000-19 999 and ≥¥20 000. The primary outcome was a composite outcome of death and major disability (modified Rankin Scale score ≥3) at 3 months after stroke onset, and secondary outcomes included major disability, death, and vascular events. A meta-analysis was conducted to incorporate the results of the current study and previous studies on the association of income level with outcomes after stroke.

Results: Within 3 months after ischaemic stroke, 1002 participants (25.20%) experienced primary outcome (880 major disabilities and 122 deaths). After multivariate adjustment, low annual household income level was associated with increased risk of the primary outcome (OR 1.60; 95% CI: 1.12 to 2.31; P_trend=0.034) when two extreme groups were compared. The meta-analysis confirmed the significant association between income level and death or major disability after stroke (pooled relative risk for lowest vs highest income level, 1.31 (95% CI: 1.18 to 1.45)).

Conclusions: Low annual household income per capita was significantly associated with increased risks of adverse clinical outcomes at 3 months after ischaemic stroke, independently of established risk factors. Further studies from other samples are needed to replicate our findings due to a reason for excluding some patients who had a severe stroke in this study.

Trial registration number: ClinicalTrials.gov (http://wwwclinicaltrialsgov) Registry (NCT01840072).

Keywords: cardiovascular diseases; functioning and disability; inequalities; stroke.