Self-monitoring of oral anticoagulation

Podcast (2)

Cochrane Library Podcast
Carl Heneghan, University of Oxford Centre for Evidence-Based Medicine, discusses a new Cochrane review of self monitoring and self management for oral anticoagulation



The results of our systematic reviews found patients capable of self-monitoring and self-adjusting therapy have fewer thromboembolic events and lower mortality than those who self-monitor alone. Pooled estimates showed significant reductions in thromboembolic events, which were reduced by half (RR 0.50, 95% CI 0.36 to 0.69) and all-cause mortality was reduced by one third. (RR 0.64, 95% CI 0.46 to 0.89). These effects were greater in participants who self-monitored  and also adjusted their own therapy (referred to as self-management).The trials of self-management alone showed significant reductions in thromboembolic events (RR 0.47, 95% CI 0.31 to 0.70) and all-cause mortality (RR 0.55, 95% CI 0.36 to 0.84);

A further study, from our group, which collected and analysed individual patient data form 11 trials of 6,417 participants and 12,800 person-years of follow-up confirmed the significant reductions in thromboembolic events in the self-monitoring group (hazard ratio 0•51; 95% CI 0•31-0•85) over five years of follow up. In addition, participants younger than 55 years showed a striking reduction in thrombotic events, with a two thirds reduction (hazard ratio 0.33, 95% CI 0.17 to 0.66), as did participants with mechanical heart valves, whose risk of a thromboembolic events was reduced by  half  (HR 0.5, 95% CI, 0.35 to 0.77). Analysis of the major outcomes in the very elderly (age ≥85 years, n=99) showed no significant adverse effects of the intervention across all outcomes.

Results from studies undertaken by our group has shown that self-monitoring of oral  anticoagulation with warfarin is a feasible and safe option. The number of people eligible for oral anticoagulation in the UK is substantial at 1 million and set to rise. Carl Heneghan and colleagues work has shown both benefits and harms of anticoagulation seem to be improved by self-monitoring: thromboembolic events were decreased by half, and major haemorrhage was also decreased. In those who also self-adjusted therapy, there is a greater reduction in thromboembolic events and mortality than self-monitoring alone. In addition to this we formed an international collaboration of trialists and showed reductions in the subset of patients with artificial heart valves was even greater, with a 2/3rd reduction in thromboembolic events at five years. Our work has also been used to underpin the Government white paper on shared decision making

Heneghan C, Ward A, Perera R; Self-Monitoring Trialist Collaboration, Bankhead C, Fuller A, Stevens R, Bradford K, Tyndel S, Alonso-Coello P, Ansell J, Beyth R, Bernardo A, Christensen TD, Cromheecke ME, Edson RG, Fitzmaurice D, Gadisseur AP, Garcia-Alamino JM, Gardiner C, Hasenkam JM, Jacobson A, Kaatz S, Kamali F, Khan TI, Knight E, Körtke H, Levi M, Matchar D, Menéndez-Jándula B, Rakovac I, Schaefer C, Siebenhofer A, Souto JC, Sunderji R, Gin K, Shalansky K, Völler H, Wagner O, Zittermann A. Self-monitoring of oral anticoagulation: systematic review and meta-analysis of individual patient data. Lancet. 2012 Jan 28;379(9813):322-34. Epub 2011 Nov 30.

Garcia-Alamino JM, Ward AM, Alonso-Coello P, Perera R, Bankhead C, Fitzmaurice D, Heneghan CJ. Self-monitoring and self-management of oral anticoagulation. Cochrane Database of Systematic Reviews 2010, Issue 4. Art. No.: CD003839. DOI:10.1002/14651858.CD003839. PMID: 20393937

Heneghan C, Alonso-Coello P, Garcia-Alamino JM, Perera R, Meats E, Glasziou P.Self-monitoring of oral anticoagulation: a systematic review and meta-analysis. Lancet. 2006 Feb 4;367(9508):404-11. Review. PMID: 16458764

Perera R, Heneghan C, Fitzmaurice D; Self Monitoring Trialists (SMT) collaboration.Individual patient meta-analysis of self-monitoring of an oral anticoagulation protocol. J Heart Valve Dis. 2008 Mar;17(2):233-8.

Heneghan C, Perera R, Ward A A, Fitzmaurice D, Meats E, Glasziou P. Assessing differential attrition in clinical trials: self-monitoring of oral anticoagulation and type II diabetes. BMC Med Res Methodol. 2007 May 2;7:18.

Associated media

1. Patients who self-monitor warfarin halve stroke risk. By Stephen Robinson, 05 December 2011.
2. By Steven Reinberg Self-Monitoring of Blood Thinner May Halve Clot Risk HealthDay Reporter
3. Prodigy. Anticoagulation – Oral  Clinical Knowledge Summaries. Anticoagulation –
4.British Committee for Standards in Haematology. Guidelines on oral anticoagulation with warfarin – fourth edition. (2011)
5. Atrial Fibrillation. National Clinical Guideline for Management in Primary and Secondary Care. NICE Clinical Guidelines, No. 36. National Collaborating Centre for Chronic Conditions (UK).
6. National Clinical Guideline centre. Venous thromboembolic diseases: the management of venous thromboembolic diseases and the role of thrombophilia testing. Venous thromboembolic diseases. Clinical Guideline Methods, evidence and recommendations. March 2012.
7. Equity and excellence: Liberating the NHS 12 July 2010;
8. Medicare Announces Expanded Coverage for Anticoagulation Patients, Opening the Door for More Patients to Test PT/INR at Home


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