Jim Slattery

Interobserver agreement for the assessment of handicap in stroke patients.

Interobserver agreement for the assessment of handicap in stroke patients was investigated in a group of 10 senior neurologists and 24 residents from two centers. One hundred patients were separately interviewed by two physicians in different combinations. The degree of handicap was recorded by each observer on the modified Rankin scale, which has six grades (0-5). The agreement rates were corrected for chance (kappa statistics). Both physicians agreed on the degree of handicap in 65 patients; they differed by one grade in 32 patients and by two grades in 3 patients. Kappa for all pairwise observations was 0.56; the value for weighted kappa (with quadratic disagreement weights) was 0.91. Our results confirm the value of the modified Rankin scale in the assessment of handicap in stroke patients; nevertheless, further improvements are possible.

Clinical and angiographic predictors of stroke and death from carotid endarterectomy: systematic review.

Abstract Objective: To identify risk factors for operative stroke and death from carotid endarterectomy. Design: Systematic review of all studies published since 1980 which related risk of stroke and death to various preoperative clinical and angiographic characteristics, including unpublished data on 1729 patients from the European carotid surgery trial. Main outcome measure: Operative risk of stroke and death. Results: Thirty six published studies fulfilled our criteria. The effect of 14 potential risk factors was examined. The odds of stroke and death were decreased in patients with ocular ischaemia alone (amaurosis fugax or retinal artery occlusion) compared with those with cerebral transient ischaemic attack or stroke (seven studies; odds ratio 0.49; 95% confidence interval 0.37 to 0.66; P<0.00001). The odds were increased in women (seven studies; 1.44; 1.14 to 1.83; P<0.005), subjects aged ≥75 years (10 studies; 1.36; 1.09 to 1.71; P<0.01), and with systolic blood pressure >180 mm Hg (four studies; 1.82; 1.37 to 2.41; P<0.0001), peripheral vascular disease (one study; 2.19; 1.40 to 3.60; P<0.0005), occlusion of the contralateral internal carotid artery (14 studies; 1.91; 1.35 to 2.69; P<0.0001), stenosis of the ipsilateral internal carotid siphon (five studies; 1.56; 1.03 to 2.36; P=0.02), and stenosis of the ipsilateral external carotid artery (one study; 1.61; 1.05 to 2.47; P=0.03). Operative risk was not significantly related to presentation with cerebral transient ischaemic attack versus stroke, diabetes, angina, recent myocardial infarction, current cigarette smoking, or plaque surface irregularity at angiography. Multiple regression analysis of data from the European carotid surgery trial identified cerebral versus ocular events at presentation, female sex, systolic hypertension, and peripheral vascular disease as independent risk factors. Conclusions: The risk of stroke and death from carotid endarterectomy is related to several clinical and angiographic characteristics. These observations may help clinicians to estimate operative risks for individual patients and will also facilitate more meaningful comparison of the operative risks of different surgeons or at different institutions by allowing some adjustment for differences in case mix. Key messages Although carotid endarterectomy has been shown to reduce the risk of stroke in selected patients, there is about a 5% operative risk of stroke and death The cost effectiveness of the operation is limited by the associated morbidity and mortality The risk of stroke and death from carotid endarterectomy is higher in women than in men Other clinical characteristics associated with an increased risk include cerebral as opposed to ocular transient ischaemic attack, age over 75 years, systolic hypertension, and peripheral vascular disease Angiographic characteristics associated with an increased operative risk include occlusion of the contralateral internal carotid artery and stenosis of the ipsilateral carotid siphon or external carotid artery

A systematic review of the risks of stroke and death due to endarterectomy for symptomatic carotid stenosis

BACKGROUND AND PURPOSE Carotid endarterectomy reduces the risk of carotid territory ischemic stroke ipsilateral to a recently symptomatic severe carotid stenosis. However, the benefit is limited by the risks of stroke and death associated with the operation. Although reported surgical risks vary enormously, there has been no systematic review of the published literature. METHODS We performed a systematic review of mortality and the risk of stroke and/or death due to endarterectomy for symptomatic carotid stenosis in studies published since 1980. RESULTS Fifty-one studies fulfilled our criteria. Overall mortality was 1.62% (95% confidence interval [CI], 1.3 to 1.9), and the risk of stroke and/or death was 5.64% (95% CI, 4.4 to 6.9). However, there was significant heterogeneity of risk of stroke and/or death (P < .001). The risk varied systematically with the methods and the authorship of the study. The risk of stroke and/or death was highest in studies in which patients were assessed by a neurologist after surgery (7.7%; 95% CI, 5.0 to 10.2) and lowest in studies with a single author affiliated with a department of surgery (2.3%; 95% CI, 1.8 to 2.7). After correcting for study methodology, there was no temporal trend in the risk of stroke and/or death between 1980 and 1995. CONCLUSIONS The reported risks of endarterectomy for symptomatic carotid stenosis show significantly greater variability than would be expected by chance. However, much of this variability can be accounted for by differences in methodology and authorship. The 5.6% overall risk of stroke and/or death is consistent with present guidelines.

Equivalence of measurements of carotid stenosis. A comparison of three methods on 1001 angiograms. European Carotid Surgery Trialists' Collaborative Group.

There is confusion about how carotid stenosis should be measured on angiograms. If the results of research based on different methods of measurement of stenosis are to be discussed and the results of clinical trials properly applied to routine clinical practice, measurements made by the different methods must be formally compared. Methods The method of measurement of stenosis used in the European Carotid Surgery Trial (ECST), that used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), and a method based on measurement of the common carotid (CC) artery lumen diameter were compared. Carotid stenosis was measured by two observers, working independently and using the three different methods of measurement, on the angiographic view of the symptomatic carotid stenosis that showed the most severe disease in 1001 patients from the ECST. Results The results of using the ECST and CC methods differed from those of using the NASCET method in the classification of stenoses as mild (0% to 29%), moderate (30% to 69%), or severe (70% to 99%) in 51% of measurements. The ECST and CC methods indicated that twice as many stenoses were severe as did the NASCET method, and classified less than a third of the number of stenoses as mild. The results of the ECST and CC methods differed from each other in 15% of measurements. The relations between measurements made by each method to those made by the others were approximately linear, so a simple equation could be derived to convert measurements made by one method to measurements made by the others. Conclusions There were major and clinically important disparities between measurements of stenosis made using different methods of measurement on the same angiograms. However, it is possible to convert measurements made by one method to those of another using a simple arithmetic equation.

Is the EuroQol a Valid Measure of Health-Related Quality of Life After Stroke?

BACKGROUND AND PURPOSE The EuroQol measures aspects of quality of life that are highly relevant to stroke patients. It is short and simple and many stroke patients can complete the form without help. However, its validity has not been adequately assessed after stroke. We therefore assessed its concurrent and discriminant validity in a group of prospectively studied stroke survivors. METHODS We assessed the validity of the EuroQol in a series of 152 patients with stroke who were all visited by a study nurse. The nurse gave the patients the EuroQol, the Frenchay Activities Index, a visual analogue pain scale, and the Hospital Anxiety and Depression Scale in the form of questionnaires to be self-completed where possible. The nurse interviewed the patient directly to assess disability using the Office of Population Censuses and Surveys Disability scale and Barthel Index. RESULTS The nurse assessed 152 patients; of these 92 were able to complete the EuroQol without help, the remaining 60 could only be assessed by interview. The EuroQol had reasonable concurrent validity; median scores on the relevant standard instruments varied significantly (and in the appropriate direction) for groups defined by their response to the relevant EuroQol domain. The EuroQol had reasonable discriminant validity since the responses enabled separation between patients with differing stroke syndromes and stroke severities. Accuracy for predicting outcome after stroke was good for both self-completed and interview-completed questionnaires. CONCLUSIONS The EuroQol appears to have acceptable concurrent and discriminant validity for the measurement of health-related quality of life after stroke. It may be administered by either a questionnaire for self-completion in patients with mild to moderate stroke or by interview in patients with significant motor deficits.

Atrial fibrillation and stroke: prevalence in different types of stroke and influence on early and long term prognosis (Oxfordshire community stroke project)

OBJECTIVE--To determine in patients with first ever stroke whether atrial fibrillation influences clinical features, the need to perform computed tomography, and prognosis. DESIGN--Observational cohort study with maximum follow up of 6.5 years. SETTING--Primary care, based on 10 general practices in urban and rural Oxfordshire. SUBJECTS--Consecutive series of 675 patients with first ever stroke registered in the Oxfordshire community stroke project. MAIN OUTCOME MEASURES--Prevalence of atrial fibrillation by type of stroke; effect of atrial fibrillation on case fatality rate and risk of recurrent stroke, vascular death, and death from all causes. RESULTS--Prevalence of atrial fibrillation was 17% (95% confidence interval 14% to 20%) for all stroke types (115/675), 18% (15% to 21%) for cerebral infarction (97/545), 11% (4% to 11%) for primary intercerebral haemorrhage (7/66), and 0% (0 to 11%) for subarachnoid haemorrhage (0/33). For patients with cerebral infarction the 30 day case fatality rate was significantly higher with atrial fibrillation (23%) than with sinus rhythm (8%); the risk of early recurrent stroke (within 30 days) was 1% with atrial fibrillation and 4% with sinus rhythm. In patients who survived at least 30 days the average annual risk of recurrent stroke was 8.2% (5.9% to 10.9%) with sinus rhythm and 11% (6.0% to 17.3%) with atrial fibrillation. CONCLUSIONS--After a first stroke atrial fibrillation was not associated with a definite excess risk of recurrent stroke, either within 30 days or within the first few years. Survivors with and without atrial fibrillation had a clinically important absolute risk of further serious vascular events.

Qualitative Comparison of the Reliability of Health Status Assessments With the EuroQol and SF-36 Questionnaires After Stroke

BACKGROUND AND PURPOSE The reliability of the EuroQol and SF-36 questionnaires after stroke is not known. We therefore aimed to assess and compare the test-retest reliability of both instruments in a group of stroke patients. METHODS A total of 2253 patients with stroke entered by United Kingdom hospitals in the International Stroke Trial were randomized to follow up with either the EuroQol or the SF-36 instruments. For both instruments, we randomly selected one third of respondents and asked them to complete another, identical questionnaire. We assessed test-retest reliability using agreement statistics: unweighted kappa statistics for the categorical domains of the EuroQol and intraclass correlation coefficients for the EuroQol visual analog scale, utility scores, and SF-36. RESULTS For the five categorical domains of the EuroQol, reproducibility was generally good (kappa ranged from 0.63 to 0.80). The reproducibility of the domains of the SF-36 was qualitatively similar for all the domains except mental health (intraclass correlation coefficient=.28). However, the 95% confidence intervals for the difference in scores between test and retest were substantial. For both instruments, reproducibility was better when the patient completed the questionnaires than when a proxy did. CONCLUSIONS Both the EuroQol and SF-36 have acceptable and qualitatively similar test-retest reliability. Therefore, either instrument might function effectively as a discriminatory measure for assessing health-related quality-of-life outcomes in groups of patients after stroke. However, our data do not support the use of either instrument for serial assessments in individual patients unless very large differences over time are expected.

A Systematic Comparison of the Risks of Stroke and Death Due to Carotid Endarterectomy for Symptomatic and Asymptomatic Stenosis

BACKGROUND AND PURPOSE There is some evidence that carotid endarterectomy reduces the risk of ipsilateral carotid territory ischemic stroke in patients with severe asymptomatic carotid stenosis. However, the benefit of endarterectomy is dependent on a low risk of stroke and/or death due to surgery. Whether the low operative risks reported in recent clinical trials and cited in recent guidelines are widely generalizable to clinical practice is unclear. Is endarterectomy for asymptomatic carotid stenosis really safer than surgery for recently symptomatic stenosis? METHODS We performed a systematic review comparing the risks of stroke and death due to carotid endarterectomy, performed by the same surgeons or in the same institutions, for symptomatic and asymptomatic stenosis in studies published since 1980. RESULTS Twenty-five studies fulfilled our criteria. Mortality within 30 days of endarterectomy was 1.31% for asymptomatic stenosis and 1.81% for symptomatic stenosis (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.49 to 0.99). The risks of fatal stroke were 0.47% and 0.91%, respectively (OR, 0.57; 95% CI, 0.34 to 0.98). The overall risk of stroke and/or death was 3.35% for asymptomatic and 5.18% for symptomatic stenosis (OR, 0.61; 95% CI, 0.51 to 0.74). CONCLUSIONS Mortality and the risk of stroke and/or death due to carotid endarterectomy are significantly lower for asymptomatic than symptomatic stenosis. These findings are consistent across virtually all studies and are likely to be widely generalizable.

Nonhypertensive cerebral small-vessel disease. An autopsy study.

BACKGROUND AND PURPOSE Cerebral small-vessel disease (SVD) is a common aging phenomenon that is exacerbated by hypertension and diabetes mellitus. It is regarded as an important cause of lacunar infarction and intracerebral hemorrhage. The present study was performed to highlight the existence and to some extent the frequency of pathologically verified SVD lacking in classic risk factors and to extend the scope of risk factor analysis. METHODS The study group comprised 70 consecutively referred autopsy brains with microscopic evidence of SVD. In each case clinical records, autopsy reports, and central nervous system and systemic autopsy histology were reviewed. SVD was graded as mild, moderate, or severe in six standardized brain regions, and the results analyzed in relation to the presence or absence of classic SVD risk factors. RESULTS SVD was manifest largely as concentric hyaline wall thickening; lipohyalinosis and fibrinoid necrosis were rarely observed. Thirty-one percent of cases failed to meet stringent clinicopathological criteria for significant prior hypertension. In 9% of cases, patients had been nonelderly, nondiabetic, and normotensive. Five of six cases lacking classic risk factors had systemic conditions known to enhance small-vessel permeability. CONCLUSIONS The nature of SVD appears to have been modified by effective treatment of hypertension. Classic risk factors are often absent. The hypothesis that a variety of conditions that enhance small-vessel permeability may contribute to the pathogenesis of SVD merits consideration.

Is stroke incidence related to season or temperature

BACKGROUND A winter excess of ischaemic stroke has been found in mortality and hospital-based studies. It is often assumed that this is due to seasonal variation in stroke incidence and several pathophysiological explanations have been proposed. We studied the incidence of stroke in relation to season and outside temperature. METHODS The data came from a community-based study of first ever in a lifetime stroke in a defined population of about 105 000. 675 such strokes were registered over four years and the month of inset was analysed separately for cerebral infarction, primary intracerebral haemorrhage, and subarachnoid haemorrhage. FINDINGS There was no significant seasonal variation. The incidence of primary intracerebral haemorrhage was increased at low temperatures, but there was no significant relation between the incidence of ischaemic stroke or subarachnoid haemorrhage and temperature. INTERPRETATION The widely reported winter excess of ischaemic strokes may be an artifact due to referral bias in hospital-based studies and increased case fatality during the winter in mortality studies.