Readability Analysis of Commonly Cited Patient-Reported Outcome Measures in the Orthopaedic Joint Literature

Patient-reported outcome measures (PROMs) are vital for assessing surgical effectiveness and capturing patient perspectives on function, symptoms, and quality of life. To ensure patients can accurately complete these tools, readability is essential. The National Institutes of Health and American Medical Association recommend patient materials be written at or below a 6th-grade reading level. This study evaluated the readability of commonly cited PROMs in the orthopaedic joint literature to assess compliance with these standards.

Thirty-five PROMs were analyzed using 2 validated readability metrics: the Flesch Reading Ease Score (FRES) and the Simple Measure of Gobbledygook (SMOG) Index. A FRES ≥80 or SMOG <7 indicated 6th-grade readability. Scores were calculated using an online readability calculator and compared to National Institutes of Health and American Medical Association guidelines.

The average FRES was 67 (range, 21-90), and the average SMOG Index was 8 (range, 6-12), indicating an overall 8th- to 9th-grade reading level. Only 6 PROMs (17%) met the readability threshold. Among the least readable were the University of California, Los Angeles Activity Score, Modified Cincinnati Knee Rating System, Hamilton Depression Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index, Kujala Score, International Knee Documentation Committee score, and Tampa Scale of Kinesiophobia.

Most PROMs commonly cited in the orthopaedic joint literature are written above the recommended 6th-grade level, which may compromise patient understanding and data quality. Improving readability through revision or development of new tools may enhance patient accessibility and the accuracy of reported outcomes.