Self-monitoring of oral anticoagulation
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.
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