Ellen Murray

Warfarin versus aspirin for stroke prevention in an elderly community population with atrial fibrillation (the Birmingham Atrial Fibrillation Treatment of the Aged Study, BAFTA): a randomised controlled trial

BACKGROUND Anticoagulants are more effective than antiplatelet agents at reducing stroke risk in patients with atrial fibrillation, but whether this benefit outweighs the increased risk of bleeding in elderly patients is unknown. We assessed whether warfarin reduced risk of major stroke, arterial embolism, or other intracranial haemorrhage compared with aspirin in elderly patients. METHODS 973 patients aged 75 years or over (mean age 81.5 years, SD 4.2) with atrial fibrillation were recruited from primary care and randomly assigned to warfarin (target international normalised ratio 2-3) or aspirin (75 mg per day). Follow-up was for a mean of 2.7 years (SD 1.2). The primary endpoint was fatal or disabling stroke (ischaemic or haemorrhagic), intracranial haemorrhage, or clinically significant arterial embolism. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN89345269. FINDINGS There were 24 primary events (21 strokes, two other intracranial haemorrhages, and one systemic embolus) in people assigned to warfarin and 48 primary events (44 strokes, one other intracranial haemorrhage, and three systemic emboli) in people assigned to aspirin (yearly risk 1.8%vs 3.8%, relative risk 0.48, 95% CI 0.28-0.80, p=0.003; absolute yearly risk reduction 2%, 95% CI 0.7-3.2). Yearly risk of extracranial haemorrhage was 1.4% (warfarin) versus 1.6% (aspirin) (relative risk 0.87, 0.43-1.73; absolute risk reduction 0.2%, -0.7 to 1.2). INTERPRETATION These data support the use of anticoagulation therapy for people aged over 75 who have atrial fibrillation, unless there are contraindications or the patient decides that the benefits are not worth the inconvenience.

Screening versus routine practice in detection of atrial fibrillation in patients aged 65 or over: cluster randomised controlled trial

Objectives To assess whether screening improves the detection of atrial fibrillation (cluster randomisation) and to compare systematic and opportunistic screening. Design Multicentred cluster randomised controlled trial, with subsidiary trial embedded within the intervention arm. Setting 50 primary care centres in England, with further individual randomisation of patients in the intervention practices. Participants 14 802 patients aged 65 or over in 25 intervention and 25 control practices. Interventions Patients in intervention practices were randomly allocated to systematic screening (invitation for electrocardiography) or opportunistic screening (pulse taking and invitation for electrocardiography if the pulse was irregular). Screening took place over 12 months in each practice from October 2001 to February 2003. No active screening took place in control practices. Main outcome measure Newly identified atrial fibrillation. Results The detection rate of new cases of atrial fibrillation was 1.63% a year in the intervention practices and 1.04% in control practices (difference 0.59%, 95% confidence interval 0.20% to 0.98%). Systematic and opportunistic screening detected similar numbers of new cases (1.62% v 1.64%, difference 0.02%, −0.5% to 0.5%). Conclusion Active screening for atrial fibrillation detects additional cases over current practice. The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography. Trial registration Current Controlled Trials ISRCTN19633732.

Self management of oral anticoagulation: randomised trial

Abstract Objective To determine the clinical effectiveness of self management compared with routine care in patients on long term oral anticoagulants. Design Multicentre open randomised controlled trial. Setting Midlands region of the UK. Participants 617 patients aged over 18 and receiving warfarin randomised to intervention (n = 337) and routine care (n = from 2470 invited; 193/337 (57%) completed the 12 month intervention. Intervention Intervention patients used a point of care device to measure international normalised ratio twice a week and a simple dosing chart to interpret their dose of warfarin. Main outcome measure Percentage of time spent within the therapeutic range of international normalised ratio. Results No significant differences were found in percentage of time in the therapeutic range between self managment and routine care (70% v 68%). Self managed patients with poor control before the study showed an improvement in control that was not seen in the routine care group. Nine patients (2.8/100 patient years) had serious adverse events in the self managed group, compared with seven (2.7/100 patient years) in the routine care arm (χ2(df = 1) = 0.02, P = 0.89). Conclusion With appropriate training, self management is safe and reliable for a sizeable proportion of patients receiving oral anticoagulation treatment. It may improve the time spent the therapeutic range for patients with initially poor control. Trial registration ISRCTN 19313375.

A randomised controlled trial of patient self management of oral anticoagulation treatment compared with primary care management

Background: The increase in numbers of patients receiving warfarin treatment has led to the development of alternative models of service delivery for oral anticoagulant monitoring. Patient self management for oral anticoagulation is a model new to the UK. This randomised trial was the first to compare routine primary care management of oral anticoagulation with patient self management. Aim: To test whether patient self management is as safe, in terms of clinical effectiveness, as primary care management within the UK, as assessed by therapeutic international normalised ratio (INR) control. Method: Patients receiving warfarin from six general practices who satisfied study entry criteria were eligible to enter the study. Eligible patients were randomised to either intervention (patient self management) or control (routine primary care management) for six months. The intervention comprised two training sessions of one to two hours duration. Patients were allowed to undertake patient self management on successful completion of training. INR testing was undertaken using a Coaguchek device and regular internal/external quality control tests were performed. Patients were advised to perform INR tests every two weeks, or weekly if a dose adjustment was made. Dosage adjustment was undertaken using a simple dosing algorithm. Results: Seventy eight of 206 (38%) patients were eligible for inclusion and, of these, 35 (45%) declined involvement or withdrew from the study. Altogether, 23 intervention and 26 control patients entered the study. There were no significant differences in INR control (per cent time in range: intervention, 74%; control, 77%). There were no serious adverse events in the intervention group, with one fatal retroperitoneal haemorrhage in the control group. Costs of patient self management were significantly greater than for routine care (£90 v £425/patient/year). Conclusion: These are the first UK data to demonstrate that patient self management is as safe as primary care management for a selected population. Further studies are needed to elucidate whether this model of care is suitable for a larger population.

An evidence‐based review and guidelines for patient self‐testing and management of oral anticoagulation

There is a limited evidence base for self‐testing and ‐management for oral anticoagulation management. Available data suggest that these are credible models for a significant minority of patients if underpinned by structured training and follow‐up. The guidelines presented are necessarily consensual and outline procedures for patient selection, training, product procurement, product maintenance, quality assurance procedures, dosage adjustment and clinical supervision. The cost‐effectiveness of these models remains to be elucidated within the UK. Further data on both health economic and clinical outcomes are required from UK based studies before widespread implementation of self‐testing and management can be recommended on a wider scale.

SPECIALIST LIAISON NURSES

General practice p 706 The number and the roles of clinical nurse specialists continue to increase in many areas of health care, despite limited evidence about their use. Some see the role as a threat to generalist nurses1 or even to primary care physicians. Nevertheless, nurses now lead services, admit and discharge patients, make autonomous clinical decisions, and organise programmes of care.2 What do we know about the use of such nurses and about their effectiveness? The largest group of specialist nurse roles, in both hospital and community settings, are Macmillan nurses, who provide palliative care, followed by specialist nurses in diabetes, asthma, stoma wound care, infection control, and HIV/AIDS.3 One more recent trend has been for clinical nurse specialists based in hospital to serve as liaison nurses to the community, providing care across organisational boundaries, particularly in chronic disease management. A database maintained at the University of Sheffield …

Patient self-management of anticoagulation therapy: A trial-based cost-effectiveness analysis

Demand for anticoagulation management is increasing due to an expansion of clinical indications for therapy. One possible model of care to meet demand is patient self‐management (PSM), beneficial to patients who need control over their condition. This study aimed to determine the cost and cost‐effectiveness of PSM of anticoagulation compared with routine clinic‐based care for patients receiving long‐term anticoagulation. A cost–utility analysis was conducted alongside a randomised controlled trial; 617 patients were recruited and followed up for 12 months. There was no significant difference in mean quality‐adjusted life years (QALYs) between groups – after adjusting for baseline, the mean difference in QALYs was 0·009 (95% CI, −0·012 to 0·030). Overall mean healthcare costs in the PSM arm were significantly higher at £417 (CI £394–£442) compared with £122 (CI £103–£144) in the control arm. Therefore, using a formal cost‐effectiveness analysis, PSM of anticoagulation does not appear to be cost‐effective. However, PSM may have other benefits in relieving pressure on traditional clinic‐based care, and the cost‐effectiveness of this model of care for some subgroups of anticoagulation patients needs to be explored further.

Point of care testing for INR monitoring: where are we now?

Point of care (POC, or near patient) testing for measurement of the international normalized ratio (INR) has facilitated the devolution of service delivery from the traditional hospital outpatient setting. However it must be undertaken within the confines of safe practice involving quality control procedures. The evaluation of INR POC tests should be closely related to the clinical issues of management and, specifically, improving the quality of care. One benefit of POC testing is in the increased motivation that some practitioners feel, being able to perform diagnostic tests without sending samples to a laboratory. POC for INR testing within primary care eliminates the delay in waiting for the result to be processed by the hospital laboratory, and the subsequent delay in informing the patient of their dosing advice. This review describes the utilization of POC testing outside the laboratory setting to develop models of care for oral anticoagulation management.

Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population (ISRCTN89345269)

BackgroundAtrial fibrillation (AF) is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly.The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting.Study designA randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire.1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa).The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic) or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular), hospital admissions (all cause, vascular), cognition, quality of life, disability and compliance with study medication.

A primary care evaluation of three near patient coagulometers.

AIM: To compare the reliability and relative costs of three international normalised ratio (INR) near patient tests. MATERIALS: Protime (ITC Technidyne), Coaguchek (Boehringer Mannheim), and TAS (Diagnostic Testing). METHODS: All patients attending one inner city general practice anticoagulation clinic were asked to participate, with two samples provided by patients not taking warfarin. A 5 ml sample of venous whole blood was taken from each patient and a drop immediately added to the prepared Coaguchek test strip followed by the Protime cuvette. The remainder was added to a citrated bottle. A drop of citrated blood was then placed on the TAS test card and the remainder sent to the reference laboratory for analysis. Parallel INR estimation was performed on the different near patient tests at each weekly anticoagulation clinic from July to December 1997. RESULTS: 19 patients receiving long term warfarin treatment provided 62 INR results. INR results ranged from 0.8-8.2 overall and 1.0-5.7 based on the laboratory method. Taking the laboratory method as the gold standard, 12/62 results were < 2.0 and 2/62 were > 4.5. There were no statistical or clinically significant differences between results from the three systems, although all near patient tests showed slightly higher mean readings than the laboratory, and 19-24% of tests would have resulted in different management decisions based on the machine used in comparison with the laboratory INR value. The cost of the near patient test systems varied substantially. CONCLUSIONS: All three near patient test systems are safe and efficient for producing acceptable and reproducible INR results within the therapeutic range in a primary care setting. All the systems were, however, subject to operator dependent variables at the time of blood letting. Adequate training in capillary blood sampling, specific use of the machines, and quality assurance procedures is therefore essential.