The use of readability formulas in health care

Abstract Abstract Readability formulas are being increasingly used to measure the understandability of written information in clinical and health settings. This paper examines the most commonly used formulas (Dale-Chall Formula, Flesch Reading Ease, Flesch-Kincaid Formula, Fog Index, Fry Readability Graph, and SMOG Grading). Their reliability and validity when used in health-related areas are discussed, and findings resulting from their use are described. These findings show that much of the material written for patients and clients, in the areas of informed consent, illnesses and their investigation and treatment, and lifestyle advice, is too difficult for many of them to understand. It is also concluded that increasing readability usually leads to improvement in understanding and occasionally in co-operation with treatment. Finally, methods for supplementing the information gained from readability formulas are described.