Factors that influence variation in clinical decision-making about thrombolysis in the treatment of acute ischaemic stroke: results of a discrete choice experiment

Abstract

BackgroundIntravenous thrombolysis for patients with acute ischaemic stroke is underused (only 80% of eligible patients receive it) and there is variation in its use across the UK. Previously, variation might have been explained by structural differences; however, continuing variation may reflect differences in clinical decision-making regarding the eligibility of patients for treatment. This variation in decision-making could lead to the underuse, or result in inappropriate use, of thrombolysis.ObjectivesTo identify the factors which contribute to variation in, and influence, clinicians’ decision-making about treating ischaemic stroke patients with intravenous thrombolysis.MethodsA discrete choice experiment (DCE) using hypothetical patient vignettes framed around areas of clinical uncertainty was conducted to better understand the influence of patient-related and clinician-related factors on clinical decision-making. An online DCE was developed following an iterative five-stage design process. UK-based clinicians involved in final decision-making about thrombolysis were invited to take part via national professional bodies of relevant medical specialties. Mixed-logit regression analyses were conducted.ResultsA total of 138 clinicians responded and opted to offer thrombolysis in 31.4% of cases. Seven patient factors were individually predictive of the increased likelihood of offering thrombolysis (compared with reference levels in brackets): stroke onset time of 2 hours 30 minutes (50 minutes); pre-stroke dependency modified Rankin Scale score (mRS) of 3 (mRS4); systolic blood pressure (SBP) of 185 mmHg (140 mmHg); stroke severity scores of National Institutes of Health Stroke Scale (NIHSS) 5 without aphasia, NIHSS 14 and NIHSS 23 (NIHSS 2 without aphasia); age 85 years (65 years); and Afro-Caribbean (white). Factors predictive of not offering thrombolysis were age 95 years; stroke onset time of 4 hours 15 minutes; severe dementia (no memory problems); and SBP of 200 mmHg. Three clinician-related factors were predictive of an increased likelihood of offering thrombolysis (perceived robustness of the evidence for thrombolysis; thrombolysing more patients in the past 12 months; and high discomfort with uncertainty) and one factor was predictive of a decreased likelihood of offering treatment (clinicians’ being comfortable treating patients outside the licensing criteria).LimitationsWe anticipated a sample size of 150–200. Nonetheless, the final sample of 138 is good considering that the total population of eligible UK clinicians is relatively small. Furthermore, data from the Royal College of Physicians suggest that our sample is representative of clinicians involved in decision-making about thrombolysis.ConclusionsThere was considerable heterogeneity among respondents in thrombolysis decision-making, indicating that clinicians differ in their thresholds for treatment across a number of patient-related factors. Respondents were significantly more likely to treat 85-year-old patients than patients aged 68 years and this probably reflects acceptance of data from Third International Stroke Trial that report benefit for patients aged > 80 years. That respondents were more likely to offer thrombolysis to patients with severe stroke than to patients with mild stroke may indicate uncertainty/concern about the risk/benefit balance in treatment of minor stroke. Findings will be disseminated via peer-review publication and presentation at national/international conferences, and will be linked to training/continuing professional development (CPD) programmes.Future workThe nature of DCE design means that only a subset of potentially influential factors could be explored. Factors not explored in this study warrant future research. Training/CPD should address the impact of non-medical influences on decision-making using evidence-based strategies.FundingThe National Institute for Health Research Health Services and Delivery Research programme.

Real-World Effectiveness of Intravenous Stroke Thrombolysis is more than the Expectation of Practicing Neurologists

“…The anticipated low outcome may be influencing the thrombolysis decisions and the rates of low thrombolysis. [ 7 8 ] Why does this discrepancy occur. We feel that it is related to the memory about really bad cases, which the physician had treated in the past.…”

“…[ 6 ] The clinical decision-making about IVTT varies among physicians. [ 7 8 ] The negative role of previous bad patient outcome in subsequent decision-making is well established. [ 9 ] In practice, most physicians remember a few patients who had no improvement (NI) or worsened following an IVTT.…”

Clinical Decision-Making for Thrombolysis of Acute Minor Stroke Using Adaptive Conjoint Analysis

“…11 Unlike more traditional vignette studies where a finite number of vignettes are constructed via variation of selected attributes that are then presented to subgroups of participants, 9,10,12 CA studies evaluate trade-offs in an individual's decision-making based on the interplay of all factors or attributes included in the survey. 13 A CA can thus be used to discover the relative importance of factors involved in a complex decision to a stakeholder. 11,13 We used the Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA) method to construct our CA via the 1000Minds online software platform.…”

“…13 A CA can thus be used to discover the relative importance of factors involved in a complex decision to a stakeholder. 11,13 We used the Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA) method to construct our CA via the 1000Minds online software platform. This method determines participants' preference values (weights) by asking simple questions involving trade-offs between attributes included in the survey.…”

“…12 Another prior survey study found that premorbid status and age greater than 80 were factors that influenced alteplase use 16 ; patient age and cognitive status also played a role in thrombolysis decision-making in a recent UK study. 13 We selected relative treatment contraindications (non-ST-segment elevation myocardial infarction in previous 3 months and genitourinary bleeding in the previous 21 days) that physicians reported being willing to disregard when surveyed. 17 Given our focus on trade-offs between attributes, we sought to avoid extreme values (eg, advanced dementia or active bleeding) when constructing our survey study to avoid biasing our results.…”