# Health Literacy and Patient-Reported Outcomes Measurement Information System Scores Among Patients Referred to Spine Surgeons

## TL;DR

This study finds that patients with lower health literacy have worse physical health scores and higher rates of hypertension when referred to spine surgeons.

## Contribution

The study is one of the first to examine health literacy's impact on outcomes in spine surgery patients using PROMIS scores and demographic data.

## Key findings

- Patients with limited health literacy were older and more likely to be patients of color.
- Lower health literacy correlated with worse physical health scores and higher rates of hypertension.
- Each unit increase in physical health score increased the odds of adequate health literacy by 16%.

## Abstract

Background

Health literacy is “the degree to which individuals can obtain, process, and understand basic health information and services to make appropriate health decisions." Low health literacy is associated with adverse health outcomes, such as increased risk and length of hospitalization after abdominal surgery. However, the impact of health literacy on outcomes in the spine surgery patient population is understudied. This study seeks to evaluate the relationship between patients' health literacy scores and various outcomes, primarily a patient's Patient-Reported Outcomes Measurement Information System (PROMIS) score at their baseline visit with a spine surgeon. A greater understanding of the impact of health literacy on health outcomes may improve treatment for patients with lower health literacy.

Methods

This is a single-center retrospective study at New York University (NYU) Langone Orthopedic Center. A health literacy measurement survey (i.e., the Newest Vital Sign survey) was administered to English-speaking adult patients aged 18 years and older who presented to two attending spine surgeons between June 1, 2022, and August 15, 2022, as new or follow-up patients. The survey consists of six questions, and patients were categorized into two different health literacy levels based on the number of correct responses. A score of 0-3 suggests limited literacy, and a score of 4-6 indicates adequate literacy. Additional data collected include PROMIS at the patient’s baseline appointment with the surgeon to create consistency between new and follow-up patients. Key demographic and clinical data were also collected. Univariate associations between health literacy and PROMIS scores were investigated using the Welch Two Sample t-test and Pearson's Chi-squared test. A multivariate analysis was carried out implementing a binary logistic regression model.

Results

This study included 57 patients with an average age of 57 years, 29 (51%) of whom identified as female. The racial breakdown of this cohort was 33 (58%) White, 11 (19%) Black, 5 (9%) Asian, and 5 (9%) Hispanic. The health literacy survey results demonstrated that 25 (44%) had limited health literacy, and 32 (56%) had adequate health literacy. Limited literacy patients were older (mean age of 62 years for Limited vs. 54 years for Adequate, P=0.024) and more likely to be patients of color (either Asian, Black, or Hispanic) (15 (60%) Limited vs. 6 (19%) Adequate, P = 0.002). Limited literacy patients also, on average, had a lower self-reported physical health score (36.6 for Limited vs. 41.2 for Adequate, P=0.050) and were more likely to have hypertension (20 (80%) Limited vs. 10 (31%) Adequate, P<0.001). A logistic regression model yielded an odds ratio of 1.16 between patient-reported physical health and health literacy, indicating that the odds of having adequate health literacy increase by about 16% for each unit increase in the Physical Health score. A Variance Inflation Factor (VIF) test was used and demonstrated minimal multicollinearity among the variables in the logistic regression.

Conclusion

This study shows that health literacy plays a significant role in health outcomes, especially in chronic health conditions like physical health for spine surgery patients and hypertension. These results align with the literature, showing how lower health literacy correlates with worse physical health scores and a greater incidence of hypertension.