Beyond surface characteristics: a new health text-specific readability measurement.

Accurate readability assessment of health related materials is a critical first step in producing easily understandable consumer health information resources and personal health records. Existing general readability formulas may not always be appropriate for the medical/consumer health domain. We developed a new health-specific readability pilot measure, based on the differences in semantic and syntactic features as well as text unit length. The tool was tested with 4 types of materials: consumer health texts, electronic health records, health news articles, and scientific biomedical journals. The results were compared with those produced by three commonly used general readability formulas. While the general formulas underestimated the difficulty of health records by placing them at the same grade levels as consumer health texts, our method rated health records as the most difficult type of documents. Our ratings, however, were highly correlated with general formulas ratings of consumer health, news, and journal articles (r=0.81 approximately 0.85, p<.0001).