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

Qual Life Res. 2009 Sep;18(7):889-900. doi: 10.1007/s11136-009-9506-y. Epub 2009 Jul 10.


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.

MeSH terms

  • Activities of Daily Living
  • Chronic Disease
  • Comprehension
  • Educational Status
  • Health Surveys*
  • Humans
  • Quality of Life*
  • Sickness Impact Profile
  • Surveys and Questionnaires / standards*