Background: Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke. Methods: We derived a score for 7-day risk of ...Background: Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke. Methods: We derived a score for 7-day risk of stroke in a population-based cohort of patients (n=209) with a probable or definite TIA (Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar pop-ulation-based cohort (Oxford Vascular Study; OXVASC, n=190). We assessed likely clinical usefulness to frontline health services by using the score to stratify all patients with suspected TIA referred to OXVASC (n=378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic (n=210; outcome: risk of stroke before appointment). Results: A six-point score derived in the OCSP (age [≥60 years=1], blood pressure [systolic >140 mm Hg and/or diastolic ≥90 mm Hg=1], clinical features [unilateral weakness=2, speech disturbance without weakness=1, other=0], and duration of symptoms in min [≥60=2, 10-59=1, < 10=0]; ABCD) was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA (p < 0.0001),in the OXVASC population-based cohort of all referrals with suspected TIA (p < 0.0001), and in the hospital-based weekly TIA clinic-referred cohort (p=0.006). In the OXVASC suspected TIA cohort, 19 of 20 (95%) strokes occurred in 101 (27%) patients with a score of 5 or greater: 7-day risk was 0.4%(95%CI 0-1.1) in 274 (73%) patients with a score less than 5, 12.1%(4.2-20.0) in 66 (18%) with a score of 5, and 31.4%(16.0-46.8) in 35 (9%) with a score of 6. In the hospitalreferred clinic cohort, 14 (7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater. Conclusions: Risk of stroke during the 7 days after TIA seems to be highly predictable. Although further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify highrisk individuals who need emergency investigation and treatment.展开更多
Clinicians often have to make treatment decisions based on the likelihood that an individual patient will benefit. In this article we consider the relevance of relative and absolute risk reductions, and draw attention...Clinicians often have to make treatment decisions based on the likelihood that an individual patient will benefit. In this article we consider the relevance of relative and absolute risk reductions, and draw attention to the importance of expressing the results of trials and subgroup analyses in terms of absolute risk. We describe the limitations of univariate subgroup analysis in situations in which there are several determinants of treatment effect, and review the potential for targeting treatments with risk models, especially when benefit is probably going to be dependent on the absolute risk of adverse outcomes with or without treatment. The ability to systematically take into account the characteristics of an individual patient and their interactions, to consider the risks and benefits of interventions separately if needed, and to provide patients with person alised estimates of their likelihood of benefit is shown using the example of endarterectomy for symptomatic carotid stenosis.展开更多
文摘Background: Effective early management of patients with transient ischaemic attacks (TIA) is undermined by an inability to predict who is at highest early risk of stroke. Methods: We derived a score for 7-day risk of stroke in a population-based cohort of patients (n=209) with a probable or definite TIA (Oxfordshire Community Stroke Project; OCSP), and validated the score in a similar pop-ulation-based cohort (Oxford Vascular Study; OXVASC, n=190). We assessed likely clinical usefulness to frontline health services by using the score to stratify all patients with suspected TIA referred to OXVASC (n=378, outcome: 7-day risk of stroke) and to a hospital-based weekly TIA clinic (n=210; outcome: risk of stroke before appointment). Results: A six-point score derived in the OCSP (age [≥60 years=1], blood pressure [systolic >140 mm Hg and/or diastolic ≥90 mm Hg=1], clinical features [unilateral weakness=2, speech disturbance without weakness=1, other=0], and duration of symptoms in min [≥60=2, 10-59=1, < 10=0]; ABCD) was highly predictive of 7-day risk of stroke in OXVASC patients with probable or definite TIA (p < 0.0001),in the OXVASC population-based cohort of all referrals with suspected TIA (p < 0.0001), and in the hospital-based weekly TIA clinic-referred cohort (p=0.006). In the OXVASC suspected TIA cohort, 19 of 20 (95%) strokes occurred in 101 (27%) patients with a score of 5 or greater: 7-day risk was 0.4%(95%CI 0-1.1) in 274 (73%) patients with a score less than 5, 12.1%(4.2-20.0) in 66 (18%) with a score of 5, and 31.4%(16.0-46.8) in 35 (9%) with a score of 6. In the hospitalreferred clinic cohort, 14 (7.5%) patients had a stroke before their scheduled appointment, all with a score of 4 or greater. Conclusions: Risk of stroke during the 7 days after TIA seems to be highly predictable. Although further validations and refinements are needed, the ABCD score can be used in routine clinical practice to identify highrisk individuals who need emergency investigation and treatment.
文摘Clinicians often have to make treatment decisions based on the likelihood that an individual patient will benefit. In this article we consider the relevance of relative and absolute risk reductions, and draw attention to the importance of expressing the results of trials and subgroup analyses in terms of absolute risk. We describe the limitations of univariate subgroup analysis in situations in which there are several determinants of treatment effect, and review the potential for targeting treatments with risk models, especially when benefit is probably going to be dependent on the absolute risk of adverse outcomes with or without treatment. The ability to systematically take into account the characteristics of an individual patient and their interactions, to consider the risks and benefits of interventions separately if needed, and to provide patients with person alised estimates of their likelihood of benefit is shown using the example of endarterectomy for symptomatic carotid stenosis.
