Supplemental patient education for patients taking oral anticoagulants: systematic review and meta-analysis

Lack of patient knowledge has been associated with poor anticoagulation control, but the effect of patient education on clinical outcomes is unclear. We systematically reviewed the effect of supplemental patient education vs. usual care on hemorrhage, thromboembolic events (TEEs), time in therapeutic range (TTR) and knowledge test scores for all oral anticoagulants.

The data sources were electronic databases, including MEDLINE, EMBASE, CENTRAL, CINAHL and IPA, to February 2012 examining any oral anticoagulant. We reviewed references for additional potentially relevant studies.

Only randomized controlled trials (RCTs) were considered. Data extraction and quality assessment were conducted with GRADE. Pooled relative risks (RRs) were calculated, and heterogeneity was determined by use of χ(2) and I(2) statistics.

Seven RCTs (n = 1209) were included in the systematic review, and five RCTs (n = 847) in the meta-analysis. All included studies examined vitamin K antagonists. No significant difference was found for hemorrhage (RR 0.92, 95% confidence interval [CI] 0.04-20.56), TEE (RR 0.66, 95% CI 0.10-4.39), a composite outcome of hemorrhage or TEE (RR 0.48, 95% CI 0.23-1.01), or TTR (mean absolute difference of 2.02%, 95% CI - 2.81 to 6.84). Evidence was conflicting on the impact of supplemental education on test scores. All trials had at least one substantial methodologic limitation.

Current evidence does not support supplemental patient education as a means to improve patient outcomes, but the quality of this evidence is poor. Larger randomized trials are needed with longer follow-up, recruitment of patients initiating anticoagulation in primary care settings, and clearly defined education interventions.