Factors that influence clinicians' decisions to offer intravenous alteplase in acute ischaemic stroke patients with uncertain treatment indication: results of a discrete choice experiment

Background: Treatment with intravenous (IV) alteplase for eligible patients with acute ischemic stroke is underused and treatment rates vary across the UK. This study sought to elucidate factors influencing variation in clinicians' decision-making about this thrombolytic treatment. Methods: A discrete choice experiment (DCE) using hypothetical patient vignettes framed around areas of clinical uncertainty was conducted with UK-based clinicians. Mixed logit regression analyses were conducted on the data. Results: 138 clinicians completed the DCE. Seven patient factors were individually predictive of increased likelihood of immediately offering IV alteplase (compared to reference levels in brackets): stroke onset time 2 hours 30 minutes [50 minutes]; pre-stroke dependency mRS 3 [mRS 4]; systolic blood pressure 185mm/Hg [140mm/Hg]; stroke severity scores of NIHSS 5 without aphasia, NIHSS 14 and NIHSS 23 [NIHSS 2 without aphasia]; age 85 [68]; Afro-Caribbean [white]. Factors predictive of withholding treatment with IV alteplase were: age 95 [68]; stroke onset time of 4 hours 15 minutes [50 minutes]; severe dementia [no memory problems]; SBP 200mm/Hg [140 mm/Hg]. Three clinician-related factors were predictive of an increased likelihood of offering IV alteplase (perceived robustness of the evidence for IV alteplase; thrombolysing more patients in the past 12 months; and high discomfort with uncertainty) and one with a decreased likelihood (high clinician comfort with treating patients outside the licencing criteria). Conclusions: Both patient and clinician-related factors have a major influence on the use of alteplase to treat patients with acute ischaemic stroke. Clinicians' views of the evidence, comfort with uncertainty and treating patients outside the licence criteria are important factors to address in programmes that seek to reduce variation in care quality about treatment with IV alteplase. Further research is needed to further understand differences in clinical decision-making about treating patients with acute ischaemic stroke with IV alteplase.