Readability formulas estimate aspects of a text's reading difficulty. Many produce a grade-level score using features such as word and sentence length. They do not directly establish whether a patient understands a message or can act on it.
AHRQ cautions that formulas can miss familiar vocabulary, coherent organization and other features of comprehension. Different formulas can give different results for the same text. The score is a prompt for editorial investigation rather than a complete quality judgment.
What a score can usefully prompt
A high result can lead a reviewer to inspect a long sentence, unnecessary jargon or a densely written explanation. Examine the passage itself before choosing an edit. Some long words are necessary; some short words are unclear in context.
Consider the original example “Contact us soon if required.” Its words are short, but it leaves “soon” and “required” undefined. A better version depends on the actual instruction: the responsible clinical or administrative team must supply the trigger, timeframe and appropriate contact. The problem cannot be solved by shortening the words further.
Do not remove a necessary warning, qualification or step merely to reach a lower score.
Use a reproducible review process
For an internal review, retain the text version, formula name, software or method, language and date. Follow the chosen method's instructions for handling headings, lists and other non-sentence material. AHRQ notes that automated scoring can produce misleading results when text is not prepared appropriately.
A suggested record separates the result from the interpretation:
- Result: the score produced by the named method on the saved text.
- Observed issue: the specific passage that needs attention.
- Revision: the change made while preserving the intended meaning.
- Further check: what a reader or content specialist still needs to confirm.
Keep a copy of the final formatted material as well. The score should remain traceable to the version actually reviewed.
Combine methods
AHRQ's patient-materials guidance recommends combining readability review with assessments of understandability and actionability, plus patient feedback. It also recommends considering the language and format patients can use. A low readability score alone does not show that a handout is understandable.
For a discharge handout, a team might separately ask whether the clinical content is correct, whether instructions are easy to locate and whether the intended reader can explain the next step. These are different questions, so record their answers separately.
Avoid describing a document as suitable for every person who completed a particular school grade. A formula evaluates features of the text; it is not an individual assessment of the patient.
Plain language addresses how to write the message. Evaluating patient education materials covers the broader review, including the limits of assessment instruments.
Sources
- Use Caution With Readability Formulas for Quality Reports (accessed 2026-09-17) — AHRQ.
- Assess, Select, and Create Easy-to-Understand Materials: Tool 11 (accessed 2026-09-17) — AHRQ.