Readability of Written Materials for CKD Patients: A Systematic Review

Am J Kidney Dis. 2015 Jun;65(6):842-50. doi: 10.1053/j.ajkd.2014.11.025. Epub 2015 Feb 4.


Background: The "average" patient has a literacy level of US grade 8 (age 13-14 years), but this may be lower for people with chronic kidney disease (CKD). Current guidelines suggest that patient education materials should be pitched at a literacy level of around 5th grade (age 10-11 years). This study aims to evaluate the readability of written materials targeted at patients with CKD.

Study design: Systematic review.

Setting & population: Patient information materials aimed at adults with CKD and written in English.

Search strategy & sources: Patient education materials designed to be printed and read, sourced from practices in Australia and online at all known websites run by relevant international CKD organizations during March 2014.

Analytical approach: Quantitative analysis of readability using Lexile Analyzer and Flesch-Kincaid tools.

Results: We analyzed 80 materials. Both Lexile Analyzer and Flesch-Kincaid analyses suggested that most materials required a minimum of grade 9 (age 14-15 years) schooling to read them. Only 5% of materials were pitched at the recommended level (grade 5).

Limitations: Readability formulas have inherent limitations and do not account for visual information. We did not consider other media through which patients with CKD may access information. Although the study covered materials from the United States, United Kingdom, and Australia, all non-Internet materials were sourced locally, and it is possible that some international paper-based materials were missed. Generalizability may be limited due to exclusion of non-English materials.

Conclusions: These findings suggest that patient information materials aimed at patients with CKD are pitched above the average patient's literacy level. This issue is compounded by cognitive decline in patients with CKD, who may have lower literacy than the average patient. It suggests that information providers need to consider their audience more carefully when preparing patient information materials, including user testing with a low-literacy patient population.

Keywords: Chronic kidney disease (CKD); Flesch-Kincaid; Lexile Analyzer; health literacy; literacy level; medical terminology; patient education; patient empowerment; patient information materials; readability; reading comprehension; renal disease; self-care; self-management of health care; shared decision making.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Australia
  • Comprehension*
  • Educational Status
  • Humans
  • Internet*
  • Patient Education as Topic*
  • Reading*
  • Renal Insufficiency, Chronic*
  • Teaching Materials / standards*