Assessing readability of patient information materials.

Four readability tests that can be used for evaluating the level of difficulty of patient drug information are described, and instructions for their use are given. Assessment of readability procedures are based on either word and sentence lengths (method 1) or word elimination from a standard list (method 2). The Flesch and Fog formulas (method 1) are suitable for determining readability levels from fifth or fourth grade, respectively, to college. The Fry readability graph (method 1) allows a quick estimation of readability levels between grade 1 and college. The Spache system (method 2), used for children's material, determines readability levels between grades 1 and 3. Using the Flesh formula, the readability levels of 111 patient-oriented brochures and pamphlets were assessed. Only 50% were written at or below the accepted standard of eighth-grade level. To fulfill its function, patient drug information should not exceed the reading level of the intended readers. The described tests provide relatively simple methods for assessing readability levels.