Medicines taken by older Australians after transient ischaemic attack or ischaemic stroke: a retrospective database study

Abstract

Background: Guidelines recommend patients diagnosed with transient ischaemic attack (TIA) or ischaemic stroke receive antihypertensive, antithrombotic and lipid lowering medicines. Reassessment of the need for medicines associated with an increased risk of stroke is also recommended.

Objective: To determine changes in the use of medicines recommended for secondary stroke prevention, medicines commonly used for treating stroke-related complications and medicines not recommended for use after ischaemic stroke, and to determine patient characteristics associated with use of all three stroke prevention medicines after TIA or ischaemic stroke. Setting Administrative health claims data from the Australian Government Department of Veterans' Affairs.

Method: This retrospective study included patients with a first-ever hospitalisation for TIA or ischaemic stroke in 2009 and alive at 4 months after discharge. Changes to medicines dispensed in the 4 months before and after hospitalisation were compared using McNemar's test. Log binomial regression analysis was used to determine patient characteristics associated with use of all three secondary stroke prevention medicines after hospitalisation for TIA or ischaemic stroke.

Main outcome measure: Prevalence of medicine use after hospitalisation.

Results: 1541 patients (853 TIA, 688 ischaemic stroke) were included, with a median age of 85 years. High use of antihypertensive (82% TIA, 86 % ischaemic stroke) and antithrombotic (84% TIA, 90% ischaemic stroke) medicines was observed postdischarge, with 58% of TIA and 73% of ischaemic stroke patients receiving lipid lowering therapy. Half of the population (47% TIA, 61% ischaemic stroke) were dispensed all three classes of medicines recommended for secondary stroke prevention after discharge. Ischaemic stroke patients, younger patients, patients with more comorbid conditions and those discharged home were more likely to receive all three recommended medicine classes. Antibiotics (45% TIA, 46% ischaemic stroke), paracetamol (44% TIA, 47% ischaemic stroke), antidepressants (26% TIA, 31% ischaemic stroke) and laxatives (24% TIA, 32% ischaemic stroke) were commonly used after discharge. Increased use of sedatives and reduced use of non-steroidal anti-inflammatories was also observed after discharge.

Conclusion: Changes to pharmacotherapy after TIA or ischaemic stroke were consistent with treatment for stroke risk factors and common stroke-related complications. Use of secondary stroke prevention medicines may be further improved among TIA patients.

Keywords: Australia; Drug utilisation; Older people; Stroke; Transient ischaemic attack.