Safety relevant knowledge of orally anticoagulated patients without self-monitoring: a baseline survey in primary care.

Background: Effective and safe management of oral anticoagulant treatment (OAT) requires a high level of patient knowledge and adherence. The aim of this study was to assess patient knowledge about OAT and factors associated with patient knowledge.

Methods: This is a baseline survey of a cluster-randomized controlled trial in 22 general practices with an educational intervention for patients or their caregivers. We assessed knowledge about general information on OAT and key facts regarding nutrition, drug-interactions and other safety precautions of 345 patients at baseline.

Results: Participants rated their knowledge about OAT as excellent to good (56%), moderate (36%) or poor (8%). However, there was a discrepancy between self-rated knowledge and evaluated actual knowledge and we observed serious knowledge gaps. Half of the participants (49%) were unaware of dietary recommendations. The majority (80%) did not know which non-prescription analgesic is the safest and 73% indicated they would not inform pharmacists about OAT. Many participants (35-75%) would not recognize important emergency situations. After adjustment in a multivariate analysis, older age and less than 10 years education remained significantly associated with lower overall score, but not with self-rated knowledge.

Conclusions: Patients have relevant knowledge gaps, potentially affecting safe and effective OAT. There is a need to assess patient knowledge and for structured education programs.

Trial Registration: Deutsches Register Klinischer Studien (German Clinical Trials Register): DRKS00000586.Universal Trial Number (UTN U1111-1118-3464).