This is the current release of the guideline.

Recommendation grades (A-C) and levels of evidence (Ia-IV) are defined at the end of the "Major Recommendations" field.

Summary Statement

• There is grade A (level Ib) evidence of the effectiveness of patient self-management.
• There is grade C (level IV) evidence of the effectiveness of patient self-testing.
• Only patients with long-term (>1 year) indications for warfarin therapy should be considered for self-testing or -management.
• There is no additional evidence to guide the selection of patients or the intensity of the training and support (including quality control testing) for patients being offered self-testing or -management.
• There is grade B (level II) evidence of the cost-effectiveness of self-management within the United States and German healthcare systems. This is founded on improved therapeutic control compared with routine care, however the routine care results are poor compared with the reported United Kingdom (UK) clinical data. No published evidence exists of cost-effectiveness within the UK healthcare system.
• No data are provided regarding the nature of patient interpretation of the international normalised ratio (INR) and no formal dosing algorithms have been published.

Guidelines for Patient Self-Testing or –Management of Oral Anticoagulation

Given the relative lack of evidence, the following recommendations are necessarily consensual (evidence level C).

1. Only patients with long-term indications for warfarin therapy should be considered for self-testing or -management. In exceptional circumstances, patients with short-term indications (e.g., first deep vein thrombosis) may be considered for self-testing, however, it should be noted that it can take 2–3 months before a patient becomes fully accustomed to this method of therapy management.
2. Only conformité européen-marked devices that have undergone acceptable evaluations by an expert, independent body (e.g. the Medicine and Healthcare Products Regulatory Agency [MHRA] in the UK) subject to external peer-review, are to be used for self-testing. Discussions should be held with the local haematologist (where appropriate) and with the Trust Point of Care (POC) committee before initiating patient self-testing. Local guidelines and procurement rules should also be checked.
3. Patients (or patient carers) must give informed consent to undertake patient self-management. This will include agreement to attend clinic regularly and to record results accurately.
4. Competence to perform an INR must be assessed by a trained healthcare professional prior to allowing home testing.
5. Competence to correctly interpret an INR result must be assessed by a healthcare professional prior to allowing self-management. This must be based on an individualized patient algorithm (Table IV of the original guideline document).
6. Previous stability of INR is not a prerequisite to home testing as unstable patients may benefit from increased autonomy and the possibility of increased frequency of testing.
7. Patients considered for self-testing or -management must have a documented INR target in line with accepted guidelines and clinical practice.
8. Contraindications for patient self-testing or –management will include previous non-compliance, in terms of either attendance at clinic or taking of medication.
9. Patients undertaking self-testing or -management must retain contact with a named clinician. This will, in most cases, be a consultant haematologist who will be clinically responsible. In all cases the patient's general practitioner (GP) and the clinician who initiated the warfarin therapy must be informed.
10. Patients undertaking self-management must be reviewed at least every 6 months by the responsible clinician.
11. Electronic quality control (QC) where available should be used each time the monitor is used.
12. The internal QC (IQC) material should be analysed when introducing a new batch/lot number of test strips or when commencing use of newly delivered test strips (even when they are the same lot number as used previously).
13. The IQC material should be re-tested if an unexpectedly high or low result occurs.
14. The IQC should be tested every 1 and 3 monthly, or with each test if the interval between testing exceeds 12 weeks.
15. Patients who are self-testing should participate in at least one form of external quality assessment (EQA), i.e., one of a, b or c below. If a patient has persistent problems the monitor should be assessed in a centre that participates satisfactorily in a formal EQA programme and patient self-testing should be suspended if persistent problems are unresolved. This is the case whichever option is employed.
    1. Patients may participate in a formal EQA programme, such as UK National External Quality Assessment Scheme (NEQAS), Common External Quality Assessment System (CEQAS) or other accredited programme.
    2. The patient's monitor may be assessed in a centre that participates satisfactorily in an accredited EQA programme, such as NEQAS. In this case, the patients should test their own blood on their own monitor/test strips and the monitor/test strips routinely used in the clinic; the INR results should be within 0.5 INR units of each other.
    3. A venous sample may be collected at the same time as the POC test and sent to an appropriate hospital laboratory for analysis. This could be carried out every 6 months for stabilised patients. In this case, INR results are acceptable if within 0.5 INR units of each other.
16. Any INR result between 4.0 and 8.0 should be repeated with the POC device to ensure that the prolonged result is not a consequence of poor sample quality. Repeat analysis should be within 0.5.
17. If an INR of >8.0 or sample error is obtained, a venous sample should be collected and analysed in an appropriate hospital laboratory.

Definitions:

Levels of Evidence

Ia Meta analysis of randomised controlled trials

Ib At least one randomised controlled trial

IIa At least one well-designed study without randomisation

IIb At least one well-designed quasi-experimental study

III Well-designed non-experimental descriptive studies

IV Expert committee reports or opinions and/or clinical experience of respected authorities

Grades of Recommendation

Grade A (evidence levels Ia, Ib) Requires at least one randomised controlled trial as part of the body of literature of overall good quality and consistency addressing the specific recommendation

Grade B (evidence levels IIa, IIb, III) Requires availability of well conducted clinical studies but no randomised controlled trials on the topic of recommendation

Grade C (evidence level IV) Requires evidence from expert committee reports or opinions and/or clinical experience of respected authorities; indicates absence of directly applicable studies of good quality

None provided

The type of supporting evidence is identified and graded for each recommendation (see "Major Recommendations").

Not applicable: The guideline was not adapted from another source.

2005 Oct

British Committee for Standards in Haematology - Professional Association

British Committee for Standards in Haematology

British Society of Haematology Taskforce for Haemostasis and Thrombosis

Task Force Members: D. A. Fitzmaurice, Department of Primary Care and General Practice, The Medical School, The University of Birmingham, Birmingham; C. Gardiner, Haemostasis Research Unit, Haematology, UCL, London; S. Kitchen, UK NEQAS for Blood coagulation, Rutledge Mews, Sheffield, UK; I. Mackie, Haemostasis Research Unit, Haematology, UCL, London; E. T. Murray, Department of Primary Care and General Practice, The Medical School, The University of Birmingham, Birmingham; S. J. Machin, Haemostasis Research Unit, Haematology, UCL, London

D. A. Fitzmaurice has received funding from Roche Diagnostics to attend research symposia.

This is the current release of the guideline.

None available

None available

This NGC summary was completed by ECRI Institute on May 23, 2008.