Abstract
INTRODUCTION: Safety warnings relating to antipsychotic-associated stroke among older persons in the UK and Italy were issued. However, the impact of these safety warnings on stroke risk has not been measured to date.
OBJECTIVE: The aim of this study was to measure the change in stroke incidence after two safety warnings in both the UK and Italy.
METHOD: A cohort study was conducted using electronic medical records representative of the UK (The Health Improvement Network) and Italy (Health Search-IQVIA Health LPD), containing data on 11 million and 1 million patients, respectively. After each drug safety warning, elderly antipsychotic new initiators were propensity-score matched 1:1:1 on antipsychotic initiators before any safety warning. Stroke incidence within 6 months of antipsychotic initiation, using an intention-to-treat approach, was the main outcome.
RESULTS: In the UK and Italy, 6342 and 7587 elderly antipsychotic initiators were identified, respectively. A 42% stroke incidence reduction was seen in the UK after the first safety warning [42.3 (95% confidence interval (CI) 35.2-50.8) vs. 24.4 [95% CI 19.0-31.2] events per 1000 person-years (PYs)], while there was a 60% stroke incidence reduction after the second warning (16.9 [95% CI 12.2-23.4] events per 1000 PYs) compared to before the first warning. There was no significant reduction in stroke incidence in Italy.
CONCLUSION: Antipsychotic safety warnings were followed by a reduction in stroke incidence among older antipsychotic users in the UK, but not Italy.
Original language | English |
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Pages (from-to) | 1471-1485 |
Number of pages | 15 |
Journal | Drug Safety |
Volume | 42 |
Issue number | 12 |
Early online date | 25 Sept 2019 |
DOIs | |
Publication status | Published - Dec 2019 |