Readability estimates for commonly used health-related quality of life surveys

Abstract

Purpose: To estimate readability of seven commonly used health-related quality of life instruments: SF-36, HUI, EQ-5D, QWB-SA, HALex, Minnesota Living with Heart Failure Questionnaire (MLHFQ), and the NEI-VFQ-25. Methods: The Flesch-Kincaid (F-K) and Flesch Reading Ease (FRE) formulae were used to estimate readability for every item in each measure. Results: The percentage of items that require more than 5 years of formal schooling according to F-K was 50 for the EQ-5D, 53 for the SF-36, 80 for the VFQ-25, 85 for the QWB-SA, 100 for the HUI, HALex, and the MLHFQ. The percentage of items deemed harder than "easy" according to FRE was 50 for the SF-36, 67 for the EQ-5D, 79 for the QWB-SA, 80 for the VFQ-25, 100 for the HUI, HALex, and the MLHFQ. Conclusions: All seven surveys have a substantial number of items with high readability levels that may not be appropriate for the general population. © 2009 The Author(s).