Risk factors for ischaemic stroke recurrence after hospitalisation

Abstract

Objective: To determine risk factors for ischaemic stroke recurrence among patients admitted to hospital for a first-ever occurrence of ischaemic stroke.

Design, setting and patients: Retrospective study involving linked hospitalisation and death records. The cohort comprised 7816 people who were hospitalised for first-ever ischaemic stroke between July 1995 and December 1999 in Western Australia. Cox's proportional hazards model was used to identify risk factors for stroke recurrence.

Main outcome measures: Time to first recurrence; cumulative recurrence risk; risk factors for recurrence.

Results: The median time to first stroke recurrence was 255 days. The cumulative probability of first recurrence was 5.1% (95% CI, 4.6%-5.7%) at 6 months, 8.4% (95% CI, 7.6%-9.1%) at 1 year and 19.8% (95% CI, 18.1%-21.4%) at 4 years. The risk of first recurrence was increased by advancing age (hazard ratio [HR], 1.03; 95% CI, 1.02-1.04), Aboriginality (HR, 1.50; 95% CI, 1.02-2.22), diabetes (HR, 1.27; 95% CI, 1.07-1.51), a history of cardiac conditions (HR, 1.18; 95% CI, 1.01-1.38), post-stroke urinary incontinence (HR, 1.27; 95% CI, 1.03-1.57) and transfer to another hospital on index admission (HR, 1.26; 95% CI, 1.08-1.46). Admission at first stroke occurrence to a hospital maintaining a stroke unit reduced the risk of recurrence (HR, 0.84; 95% CI, 0.72-0.99).

Conclusion: The risk factors identified in our study have implications for planning secondary prevention strategies. In particular, Aboriginality and transfer to another hospital upon admission for first-ever ischaemic stroke were important risk factors. Research into the level of compliance and access to stroke treatment by Aboriginal patients to prevent further strokes is required.