Patient comprehension of written drug information.

The effect of the readability level of patient drug information materials on patient comprehension of and attitude toward the information was studied. The reading level of 108 outpatients at a Veterans Administration hospital who could read English, read type of normal size, and who were not receiving warfarin sodium was measured. Patients then were given, on a random basis, a warfarin drug monograph written on either the 5th- or 10th-grade level. To test comprehension, all subjects took a true-false test of recall written at the 5th-grade level. A significant relationship was found between comprehension and reading ability (p less than 0.001). Patients receiving the 5th-grade level monograph exhibited significantly better comprehension than those receiving the 10th-grade level material (p less than 0.001). As compared with those getting 10th-grade material, the group receiving the 5th-grade material had a more favorable perception of the level of difficulty, understandability, and clarity of the material. The study indicates that comprehension of written patient drug information can be improved by adjusting the readability of informational materials to the reading level of the patients.