Academic journal article Bulletin of the World Health Organization

Improving Stroke Outcome: The Benefits of Increasing Availability of Technology

Academic journal article Bulletin of the World Health Organization

Improving Stroke Outcome: The Benefits of Increasing Availability of Technology

Article excerpt

Voir page 1341 le resume en francais. En la pagina 1342 figura un resumen en espanol.

Introduction

Stroke presents a major public health challenge, with a high case fatality and a large proportion of survivors dependent on nursing and other care. Over the past few years clinical practice has changed considerably -- especially in the investigation of stroke -- and there are several promising interventions being developed, including new drug treatments (1). Clinical guidelines (e.g., from the American Heart Association (2) and the Scottish Intercollegiate Guidelines Network (3)) are now being developed to guide best practice in the context of these new developments in clinical care. Consensus guidelines are recognized to vary and to need an international perspective (4). Because many of the investigations and treatments featured are not widely available in the developing world, we aimed to explore the potential benefits on stroke outcome of management strategies associated with reduced availability of resources.

Materials and methods

A decision analysis was performed with the data package program (5). We chose the outcome of death or dependency (i.e. continued physical dependence) as this is used in many of the trials from which data are available. The converse of this outcome is functional independence. We have taken a six-month end-point.

We defined four settings according to the resources available and the subsequent interventions that could be provided. The interventions selected are supported by more than one randomized trial (Box 1).

Box 1. Definition of settings

Setting 1: very high technology

This setting includes immediate computed tomography scanning, which allows the exclusion of a cerebral haemorrhage. This enables the use of thrombolysis in appropriate patients arriving at hospital early, the use of anticoagulation in those with presumed cerebral emboli and aspirin to be given early. This setting also includes organized multidisciplinary care in a stroke unit.

Setting 2: high technology

This setting includes non-urgent computed tomography scanning and organized care in a stroke unit. The non-urgency of computed tomography scanning precludes the use of thrombolysis and allows aspirin and anticoagulants to be given after (say) 48 hours.

Setting 3: intermediate technology

This setting has no computed tomography scanning but does have organized care in a stroke unit. Aspirin and anticoagulants are given late (2-4 weeks) to avoid the major increase in risk among those who have a haemorrhagic stroke. It is, however, anticipated that both treatments carry an increased risk of rebleeding when given to patients with an undiagnosed haemorrhagic stroke.

Setting 4: low technology

This setting has no computed tomography scanning or organized care in a stroke unit. The only intervention is aspirin given late (2-4 weeks), which has the problems mentioned above.

We estimated the proportions of the major types of stroke and the expected outcomes from the literature (6-12) to allow us to perform a decision analysis (Box 2). The benefits and risks of each intervention have also been determined from a review of the literature (see Table 1).

Box 2. Sources of data for decision analysis Values in bold face were used for the initial decision analysis

Baseline data

We have excluded subarachnoid haemorrhage and unclassified stroke -- which together represent 10--20% of the total population with stroke (6, 7) -- owing to their different clinical presentation and management.

11% of stroke patients (after excluding above) have primary intracerebral haemorrhage (6, 7) and 89% have cerebral infarction.

Atrial fibrillation may be found in 18-29% of patients with infarct and 11-19% of those with haemorrhage (8, 9). We have not added intracardiac or carotid sources of emboli to these figures, and we have assumed that all those with embolic causes of cerebral infarction will be included among those with atrial fibrillation. …

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