INR
Self-Monitoring and self-management of oral anticoagulation IPD
Investigators: Dr Carl Heneghan, Dr Alison Ward and Prof David Fitzmaurice, Dr Rafael Perera, Richard Stevens, Clare Bankhead and Alice Fuller
In the UK, over 1 million patients are currently receiving anticoagulation therapy. Regular blood tests to monitor INR levels are necessary to minimize the risk of adverse events such as thrombosis or haemorrhage. A major aspect of our work is an international collaborative individual patient data meta-analysis of oral anticoagulation self-monitoring. A collaborators workshop was held in Brussels October 2009 and the final paper will be drafted by the Collaborative Group.
Self-Monitoring and self-management of oral anticoagulation
Cochrane systematic review
Investigators: Josep Garcia-Alamino, Alison Ward, Pablo Alonso-Coello, Rafael Perera, Clare Bankhead, David Fitzmaurice, Carl Heneghan
The introduction of portablemonitors (point-of-care devices) for the management of patients on oral anticoagulation allows self-testing by the patient at home. Patients who self-test can either adjust their medication according to a pre-determined dose-INR schedule (self management) or they can call a clinic to be told the appropriate dose adjustment (self-monitoring). Several trials of self-monitoring of oral anticoagulant therapy suggest this may be equal to or better than standard monitoring. We conducted a systematic review to evaluate the effects of self-monitoring or self-management of oral anticoagulant therapy compared to standard monitoring. We found that Compared to standard monitoring, patients who self-monitor or self-manage can improve the quality of their oral anticoagulation therapy. The number of thromboembolic events and mortality were decreased without increases in harms. However, self-monitoring or self-management were not feasible for up to half of the patients requiring anticoagulant therapy. Reasons included patient refusal, exclusion by their general practitioner, and inability to complete training.
Systematic review of control measures
Investigators: Dr Carl Heneghan, Dr Rafael Perera, Dr Clare Bankhead and Paul Glasziou
To date, there has been no systematic examination of the relationship between international normalized ratio (INR) control measurements and the prediction of adverse events in patients with atrial fibrillation on oral anticoagulation.
This study focuses on the commonly reported INR control measures: percentage of time in therapeutic range [TTR] and percentage of INRs in range; and the outcomes of major hemorrhage and thromboembolic events with the aim of identifying association between control and these outcomes. This would allow us to recommend which control measure to use in patients taking oral anticoagulants for atrial fibrillation.
Interventions
Investigators: Alison Ward, Carl Heneghan, Sally Tyndel, Paul Glasziou
We know from previous studies that it is often difficult to replicate interventions reported in randomised controlled trials due to missing information. We aim to develop precise descriptions of recommended INR self-monitoring interventions. Two clinicians have rated 17 INR self-monitoring trials, focusing on 10 areas of the interventions. Furthermore, we have extracted data on the education and self-monitoring components of the interventions, and identified gaps in the descriptions. We aim to develop a methodology to agree what variance in the descriptions is acceptable, using a consensus process with a panel of clinicians or experts.
Once we have the full descriptions, we can begin to establish whether there are associations between factors, such as compliance and attrition and the complexity of the intervention. After completing the process for self-monitoring of INR and developing a generic methodology, we plan to adapt this to extract data on HbA1c, blood pressure, heart failure, and any other monitoring interventions within the monitoring programme.
Loading Dose
Project Leads: Dr Carl Heneghan, Sally Tyndel, Dr Clare Bankhead, Dr Yi Wan and Dr Alison Ward
Selection of the right warfarin dose is not straightforward, particularly at the outset. We have systematically reviewed the literature on the most effective methods for initiating warfarin and an observational study of 7000 patients going back to 2001 is currently in the analysis phases.
CASM Study
Project Leads: Dr Alison Ward, Dr Carl Heneghan, David Fitzmaurice, Stephen Sutton, Rafael Perera, Sally Tyndell and David Mant
The research proposed in this study is designed to underpin the development of an intervention to ensure that self-monitoring of INR can be introduced safely in the UK and with minimal waste of resources.
Aims:
1. To estimate the current levels of control, efficacy and adverse events in patients who commence self-monitoring of oral anticoagulation therapy (OAT) in the UK
2. To explore the factors which predict success and failure in self-monitoring of OAT
3. To ascertain whether the success in INR and level of side-effects reported from RCTs by self-monitoring for OAT are translated to a non-selected population
4. To estimate the adequacy of existing training and QA arrangements by measuring
the proportion of individuals currently achieving safe self-monitoring in routine clinical practice
5. To collect data to allow us to set minimum criteria for self-monitoring, define minimum training, and recommend quality assurance arrangements during the initial monitoring period
The study is currently in recruitment and has been awarded NIHR research for patient benefit scheme funding