Health Information on Pre-Exposure Prophylaxis From Search Engines and Twitter: Readability Analysis

Abstract

Background: Pre-exposure prophylaxis (PrEP) is proven to prevent HIV infection. However, PrEP uptake to date has been limited and inequitable. Analyzing the readability of existing PrEP-related information is important to understand the potential impact of available PrEP information on PrEP uptake and identify opportunities to improve PrEP-related education and communication.

Objective: We examined the readability of web-based PrEP information identified using search engines and on Twitter. We investigated the readability of web-based PrEP documents, stratified by how the PrEP document was obtained on the web, information source, document format and communication method, PrEP modality, and intended audience.

Methods: Web-based PrEP information in English was systematically identified using search engines and the Twitter API. We manually verified and categorized results and described the method used to obtain information, information source, document format and communication method, PrEP modality, and intended audience. Documents were converted to plain text for the analysis and readability of the collected documents was assessed using 4 readability indices. We conducted pairwise comparisons of readability based on how the PrEP document was obtained on the web, information source, document format, communication method, PrEP modality, and intended audience, then adjusted for multiple comparisons.

Results: A total of 463 documents were identified. Overall, the readability of web-based PrEP information was at a higher level (10.2-grade reading level) than what is recommended for health information provided to the general public (ninth-grade reading level, as suggested by the Department of Health and Human Services). Brochures (n=33, 7% of all identified resources) were the only type of PrEP materials that achieved the target of ninth-grade reading level.

Conclusions: Web-based PrEP information is often written at a complex level for potential and current PrEP users to understand. This may hinder PrEP uptake for some people who would benefit from it. The readability of PrEP-related information found on the web should be improved to align more closely with health communication guidelines for reading level to improve access to this important health information, facilitate informed decisions by those with a need for PrEP, and realize national prevention goals for PrEP uptake and reducing new HIV infections in the United States.

Keywords: HIV; PrEP; Twitter; electronic health education; health education materials; health information; health literacy; infection; pre-exposure prophylaxis; prophylaxis; readability.

Figure 1

The empirical distribution of the average readability level required for understanding web-based pre-exposure prophylaxis information.

Figure 2

Examples of document types used to disseminate pre-exposure prophylaxis (PrEP) information on the web: information sheet (top left), brochure (top right), website (bottom left), and website in a blog format (bottom right). More information about each document, including the source URL, can be found in Multimedia Appendix 1, rows 12, 272, 114, and 147. For a higher-resolution version of this figure, see Multimedia Appendix 2.