Readability Level of English and Spanish Online Patient Education Materials for Knee Injections

Introduction Health literacy is tied to health outcomes and health disparities, with a significant portion of patients utilizing online patient education materials (OPEM) in medical decision-making. However, orthopedic OPEM are often written above the average eighth-grade reading level of adults in the United States, making them inaccessible to the public. Although there are increasingly more studies examining readability of OPEM, there is a gap in literature on readability of OPEM for knee injections. Also, despite the large Spanish-speaking population, few studies have investigated the readability of Spanish OPEM. Objective Our study aimed to determine whether the English and Spanish OPEM for corticosteroid, platelet-rich plasma (PRP), and hyaluronic knee injections exceeded the average eighth-grade reading level of adults in the United States. Our secondary aim was to determine if there is a significant difference in readability of OPEM for English versus Spanish and for corticosteroid versus PRP versus hyaluronic acid. Methods Two independent reviewers used search terms in Google to identify the top twenty-five English and Spanish OPEM for corticosteroid, PRP, and hyaluronic acid. The name, URL, and classification (i.e. hospital, healthcare organization, professional society) of each web page was recorded. The English pages were analyzed with an online readability calculator, Readable. Well-validated metrics such as Flesch-Kincaid Grade Level (FKGL), Flesch Reading Ease (FRE), Gunning-Fog Index (GFI), Coleman-Liau Index (CLI), and Simple Measure of Gobbledygook (SMOG) were recorded. For Spanish pages, an online calculator, Spanish Readability, was used to determine Fernández-Huerta Index (FHI), FHI grade level, INFLSZ, INFLESZ grade level, Spaulding index, Spaulding grade level, and Crawford grade level. Independent-samples t-test, one-way ANOVA, Fischer’s exact test, and bivariate correlation analysis using Pearson’s coefficient were used to evaluate the readability metrics. Results The overall mean grade level of English OPEM was significantly higher than that of Spanish OPEM for corticosteroid (12.14 ± 2.32 vs 9.49 ± 1.13, p < 0.001). Similarly, the overall mean grade level of search results of English OPEM for PRP was significantly higher than that of its Spanish counterpart (12.24 ± 1.46 vs 9.62 ± 1.10, p < 0.001). Additionally, the overall mean grade level of English for hyaluronic acid was significantly higher than its Spanish counterpart (12.32 ± 1.91 vs 9.49 ± 1.13, p < 0.001). Zero English or Spanish OPEM pertaining to steroid, PRP, or hyaluronic injections of the knee were written below a seventh-grade reading level. When comparing the mean grade levels of the English steroid, PRP, and hyaluronic acid OPEMs to one another, a one-way ANOVA revealed no significant difference (p = 0.947); similarly, a one-way ANOVA revealing no significant difference (p = 0.891) was found when comparing the Spanish steroid, PRP, and hyaluronic acid OPEMs to one another. Conclusions To the best of our knowledge, our study is the first to compare the readability of English versus Spanish OPEM for corticosteroid, PRP, and hyaluronic knee injections. We found that the readability for all injections in both English and Spanish were written significantly higher than the average eighth-grade reading level in the US.