Background: Accurate assessment of the difficulty of consumer health texts is a prerequisite for improving readability. General purpose readability formulas based primarily on word length are not well suited for the health domain, where short technical terms may be unfamiliar to consumers. To address this need, we previously developed a regression model for predicting "average familiarity" with consumer health vocabulary (CHV) terms.
Objective: The primary goal was to evaluate the ability of the CHV term familiarity model to predict (1) surface-level familiarity of health-related terms and (2) understanding of the underlying meaning (concept familiarity) among actual consumers. Secondary goals involved exploring the effect of demographic factors (eg, health literacy) on surface-level and concept-level familiarity and describing the relationship between the two levels of familiarity.
Methods: Survey instruments for assessing surface-level familiarity (45 items) and concept-level familiarity (15 items) were developed. All participants also completed a demographic survey and a standardized health literacy assessment, S-TOFHLA.
Results: Based on surveys completed by 52 consumers, linear regression suggests that predicted CHV term familiarity is a statistically significantly predictor (P < .001) of participants' surface-level and concept-level familiarity performance. Health literacy was a statistically significant predictor of surface-level familiarity scores (P < .001); its effect on concept-level familiarity scores warrants further investigation (P = 0.06). Educational level was not a significant predictor of either type of familiarity. Participant scores indicated that conceptualization lagged behind recognition, especially for terms predicted as "likely to be familiar" (P = .006).
Conclusions: This exploratory study suggests that the CHV term familiarity model is predictive of consumer recognition and understanding of terms in the health domain. Potential uses of such a model include readability formulas tailored to the consumer health domain and tools to "translate" professional medical documents into text that is more accessible to consumers. The study also highlights the usefulness of distinguishing between surface-level term familiarity and deeper concept understanding and presents one method for assessing familiarity at each level.