Evaluation of warfarin (W) patient information

Abstract

Background Adverse patient events post-discharge have been linked to poor communication between patients and practitioners. A common setting where patients receive written communication is their community pharmacy. The quality of written patient drug information has rarely been assessed with systematic methods. Aim This study was conducted to determine the accuracy of W patient information sheets using the consensus-based information website of the Thrombosis Interest Group of Canada (TIG) as a ‘gold standard’. In addition, the reading level of each information sheet was assessed and compared against the national literary standard. Methods Surveys were sent to the 47 members of the TIG to establish a consensus of important items for inclusion into a W information sheet. W patient information sheets/booklets distributed by Ontario (On) community pharmacies were collected and evaluated against the standard by 3 of the investigators. The reading level was assessed using 2 standarndized formulae, the Flesch-Kincaid and SMOG scales. Results The consensus created a checklist of 50 essential of important items against which the pharmacy sheets were compared. W information sheets representing 97% of On community pharmacies were analyzed. On average, W information sheets contained 40% of the necessary information while booklets produced by manufacturers of W contained on average 75% of the necessary information. Many of the W information sheets contained incorrect information. The average reading level of these sources of W information was a grade 10 level. Conclusions Sources of W information distributed by On pharmacies fail to fully address all the essential information required, and W information sheets contain incorrect information. Most of the information is written above the average reading level of adult Canadians. Implications Patient drug information sheets require input from practitioners who manage patients on the drug(s) in question. Other drug information sheets should be evaluated in a similar manner.