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Biomedical subjects

P Sandercock

Publications and source records attributed to P Sandercock.

At least 91 records · Page 5Linked to original sources

A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project--1981-86. 2. Incidence, case fatality rates and overall outcome at one year of cerebral infarction, primary intracerebral and subarachnoid haemorrhage.

The age and sex specific incidence rates for cerebral infarction, primary intracerebral haemorrhage and subarachnoid haemorrhage in a population of approximately 105,000 are presented. Over four years 675 patients with a first-ever stroke were registered with the Oxfordshire Community Stroke Project. The pathological diagnosis was confirmed by computerised tomography (CT) scan, necropsy or lumbar puncture (cases of subarachnoid haemorrhage only) in 78% of cases and a further 17% were diagnosed according to the Guy's Hospital Stroke Diagnostic Score. The proportion of all first-ever strokes by pathological type was: cerebral infarction 81% (95% confidence interval 78-84), primary intracerebral haemorrhage 10% (8-12), subarachnoid haemorrhage 5% (3-7) and uncertain type 5% (3-7). These proportions are similar to other community-based studies. The overall 30 day case fatality rate was 19% (16-22), that for cerebral infarction being 10% (7-13), primary intracerebral haemorrhage 50% (38-62) and subarachnoid haemorrhage 46% (29-63). One year post stroke 23% (19-27) with cerebral infarction were dead and 65% (60-70) of survivors were functionally independent. The figures for primary intracerebral haemorrhage were 62% (43-81) dead and 68% (50-86) of survivors functionally independent and for subarachnoid haemorrhage were 48% (24-72) dead and 76% (56-96) of survivors functionally independent. There are important differences between these rates and those from other sources possibly due to more complete case ascertainment in our study. Nevertheless, the generally more optimistic early prognosis in our study, particularly for cases of cerebral infarction, has important implications for the planning of clinical trials and for the expected impact that any treatment might have on the general population.

Adolescent↗

The frequency, causes and timing of death within 30 days of a first stroke: the Oxfordshire Community Stroke Project.

In a prospective, community-based study of 675 consecutive patients with a first-ever stroke, of whom over 90% had computed tomography (CT) and/or necropsy examinations, 129 deaths occurred within 30 days of the onset of symptoms, a case fatality rate (CFR) of 19%. The 30 day CFR for patients with cerebral infarction was 10% (57 of 545, for primary intracerebral haemorrhage 52% (34 of 66), for subarachnoid haemorrhage 45% (15 of 33) and for those of uncertain pathological type 74% (23 of 31). The CFR for patients who had been functionally dependent pre-stroke was 33% compared with 17% for those who had been independent pre-stroke. The age-adjusted relative risk of death for patients who had been functionally dependent pre-stroke was not significantly greater (1.8, 95% confidence interval 0 to 4.3). There was a significant trend for CFR to increase with age (Chi square for trend = 4.0, p less than 0.05). This relationship was found in those patients who had been functionally independent prestroke (Chi square for trend = 7.9, p less than 0.005) but not in those who had been dependent pre-stroke (Chi square for trend = 0.5, NS). The pattern of increasing CFR with increasing age amongst those who had been independent prestroke was seen particularly in patients with cerebral infarction (Chi square for trend = 8.6, p less than 0.005). The age-adjusted relative risk of death for patients with cerebral infarction who had been functionally dependent pre-stroke was 2.2 (95% confidence interval 1.2 to 4.1). Fifty three percent of all deaths within 30 days of stroke were due to the direct neurological sequelae of the stroke. Patients with primary intracerebral or subarachnoid haemorrhages were significantly more likely to die in this way than those with cerebral infarction (relative risk 4.1; 95% confidence interval 3.4-4.9) and 56% of such deaths occurred within 72 hours of onset. In patients with cerebral infarction, 51% of deaths were due to complications of immobility (for example, pneumonia, pulmonary embolism) and these were more likely to occur after the first week. These findings have implications for clinical practice and the planning of clinical trials.

Aged↗

A simple method to improve the accuracy of non-invasive ultrasound in selecting TIA patients for cerebral angiography.

A prospective study is reported of the ability of B mode ultrasound imaging and continuous wave Doppler flow studies to detect different degrees of stenosis of the extracranial internal carotid artery (ICA) in 186 arteries in 99 patients with transient ischaemic attacks (TIA) and minor ischaemic stroke. A simple mathematical equation has been developed which combines the image and flow data to provide a single predictor of the degree of angiographic stenosis which has advantages over either ultrasonic modality used alone. The sensitivity and specificity of the predictive model in the detection of stenosis greater than or equal to 25% was 73% and 98%, of stenosis greater than or equal to 50% was 90% and 93%, of stenosis greater than or equal to 75%, 65% and 99% and occlusion 100% and 94% respectively. The principal clinical value of ultrasound screening is to spare patients with "non-significant" stenosis the risk of unnecessary angiography. Thus a simple measure of the Duplex screening tests' performance is the proportion of all strokes occurring as a complication of angiography that are avoided by changing the investigation policy from "angiograms for all carotid TIA and minor ischaemic stroke patients" to "angiograms for all patients with abnormal ultrasound results". If Duplex scanning were used to select patients most likely to have a significant abnormality on angiography, depending on the degree of stenosis to be detected, 52-85% of angiographic strokes might be avoided. If the predictive equation were used 62-88% of angiographic strokes might be avoided.

Blood Flow Velocity↗

Prognosis of transient ischemic attacks in the Oxfordshire Community Stroke Project.

In a community-based study of approximately 105,000 people, 184 presented with a transient ischemic attack during the 5 years between 1981 and 1986; we believe these persons represent almost all new cases of transient ischemic attack going to a doctor during that period. During a mean follow-up of 3.7 years 49 patients died, 45 had a first-ever stroke, and 17 had a myocardial infarction. Cardiac disease accounted for 17 (35%) deaths, while stroke was the cause of death in 15 patients (31%). The average actuarial risk of death was approximately 6.3%/yr, slightly greater than that expected for similar people without transient ischemic attacks (risk ratio [observed divided by expected] = 1.4). The actuarial risk of stroke was 11.6% during the first year after a transient ischemic attack and approximately 5.9%/yr over the first 5 years. Patients who suffered a transient ischemic attack had a 13-fold excess risk of stroke during the first year and a sevenfold excess risk over the first 7 years compared with people without transient ischemic attacks. The actuarial risk of death, stroke, or myocardial infarction over the first 5 years after a transient ischemic attack was approximately 8.4%/yr. The prognosis in this community-based cohort was better than that in previous reports. The high early risk of stroke means that investigation and treatment of new cases should commence as soon as possible.

Cerebrovascular Disorders↗

Projecting the number of patients with first ever strokes and patients newly handicapped by stroke in England and Wales.

The common assumption that future increases in the number of elderly people will result in a parallel increase in the burden of care of long term disabled survivors of stroke was examined. The number of patients with first ever strokes and the net number of people handicapped after these strokes in England and Wales every five years until 2023 have been projected. Between the base year 1983 and the year 2023 an increase in population of about 5% will occur; first ever strokes are projected to increase by about 30% and deaths within six months of first ever strokes by about 40%. The net number of severely handicapped people six months after a first ever stroke is projected to increase by only about 8%, however, and the net number of people who are moderately or severely handicapped by only 4%. This paradox occurs because first ever stroke often kills people who have been handicapped by other causes, particularly if they are elderly. It is concluded that despite the limitations of these data they strongly suggest that the increased burden of health care of patients with first ever strokes in the next 40 years will be primarily that of caring for those in the acute stages of stroke and not with the management of chronic handicap after a stroke.

Age Factors↗

The odds ratio: a useful tool in neurosciences.

The odds ratio is very useful; when used as a measure of association (or to describe the results of a randomised controlled treatment trial) it expresses both the strength and direction of the association (or size and direction of treatment effect). Its 95% confidence interval estimates the likely degree of sampling error and provides a test of significance at the 5% level. Authors, when reporting the results of descriptive studies, case-control studies and randomised controlled trials, should consider presenting their results this way rather than by simple significance testing with a chi squared test.

Cerebrovascular Disorders↗

A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project 1981-86. 1. Methodology, demography and incident cases of first-ever stroke.

A prospective study of acute cerebrovascular disease in a community of about 105,000 people is reported. The study protocol combined rapid clinical assessment of patients with accurate diagnosis of the pathological type of stroke by CT or necropsy, whether or not they were admitted to hospital. The study population was defined as those people who were registered with one of 50 collaborating general practitioners (GPs). Referrals to the study were primarily from the GPs though, to ensure complete case ascertainment, hospital casualty and admission registers, death certificates and special data from the Oxford Record Linkage Study were also scrutinized. Six hundred and seventy five cases of clinically definite first-ever in a lifetime stroke were registered in four years yielding a crude annual incidence of 1.60/1,000 or 2.00/1,000 when adjusted to the 1981 population of England and Wales. The age and sex specific incidence rates for first stroke showed a steep rise with age for both sexes. The odds of a male sustaining a first stroke were 26% greater than those of a female. Ninety one per cent of patients were examined in a median time of four days after the event by a study neurologist and 88% had cerebral CT or necropsy.

Adolescent↗

Why are patients with acute stroke admitted to hospital?

Data on 515 consecutive patients registered with the Oxfordshire Community Stroke Project were used to compare the characteristics of those patients who were admitted to hospital within one month after their first stroke with those who remained in the community during that time. Twenty eight patients had their stroke while in hospital for other conditions, and of the remaining 487, 266 were admitted. Though patients with a severe neurological deficit were significantly more likely to be admitted, 47 out of 202 such patients were managed in the community. In a substudy of 162 consecutive patients the general practitioners' reasons for either arranging admission to hospital or continuing with community care in the first week after the stroke were ascertained. Sixty patients were admitted. The only reason for admission was diagnostic uncertainty in five cases (though this was a contributing factor in 25) and to provide nursing or general, non-medical care in 25. Patients who lived alone were more likely to be admitted. All 12 patients who presented directly to the casualty department were admitted, though only five had had a severe stroke. A stroke service that provides a facility for rapid outpatient and domiciliary diagnosis as well as a rapidly acting domiciliary nursing team might reduce the number of patients with stroke admitted to hospital without adversely affecting the quality of patient care: this should be properly evaluated.

Acute Disease↗

Is a controlled trial of long-term oral anticoagulants in patients with stroke and non-rheumatic atrial fibrillation worthwhile?

A controlled randomised trial large enough to assess the value of anticoagulating stroke patients in atrial fibrillation would be difficult to conduct in the UK and the results would be applicable to only a small proportion of stroke patients. It would be more worthwhile to organise a trial that also assessed the value of other treatments that are simpler and applicable to all stroke patients. A trial that assessed the value of aspirin and beta-blockers against control in all stroke patients would not cost much more than one restricted to comparing anticoagulants against control in patients with stroke and atrial fibrillation but would provide information of more relevance to the management of patients with stroke in the UK.

Administration, Oral↗