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 management 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 (chi2(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.