Unsupervised Machine Learning to Detect and Characterize Barriers to PrEP Therapy: A Multiplatform Social Media Study (Preprint)

Abstract

Among racial and ethnic minority groups, the risk of HIV infection is an ongoing public health challenge. PrEP (pre-exposure prophylaxis) is highly effective for preventing HIV when taken as prescribed. However, there is a need to understand experiences, attitudes, and barriers of PrEP for racial and ethnic minority populations, and sexual minority groups.

This infodemiology study aimed to leverage big data and unsupervised machine learning to identify, characterize, and elucidate on experiences and attitudes regarding perceived barriers associated with uptake and adherence to PrEP therapy. The study also specifically examined self-reported experiences from racial or ethnic populations and sexual minority users.

The study used data mining approaches to collect posts from popular social media platforms Twitter, YouTube, Tumblr, Instagram, and Reddit. Posts were selected by filtering for keywords associated with PrEP, HIV, and approved PrEP therapies. We analyzed data using unsupervised machine learning followed by manual annotation using a deductive coding approach to characterize PrEP and other HIV prevention-related themes discussed by users.

We collected a total of 522,430 posts over a 60-day period, including 408,637 (78.22%) Tweets, 13,768 (2.63%) YouTube comments, 8,728 (1.67%) Tumblr posts, 88,177 (16.88%) Instagram posts, and 3,120 (0.60%) Reddit posts. After applying unsupervised machine learning and content analysis, a total of 785 posts were identified that specifically related to barriers to PrEP and were grouped into three major thematic domains including the: (a) provider level (n=13 posts, 1.66%); (b) patient-level (n=570, 72.61%), and (c) community level (n=166, 21.15%). The main barriers identified in these categories included those associated with knowledge (lack of knowledge about PrEP); access issues (lack of insurance coverage, no prescription, and impact of COVID-19 pandemic); and adherence (subjective reasons for why users terminated PrEP or decided not to start PrEP, including side effects, alternative HIV prevention measures, and social stigma). Among all PrEP posts, we identified 320 (40.76%) posts where users self-identified as racial or ethnic minority, or as a sexual minority population with their own specific PrEP barriers and concerns.

Both objective and subjective reasons were identified as barriers reported by social media users when initiating, accessing, and adhering to PrEP. Though ample evidence supports PrEP as an effective HIV prevention strategy, user-generated posts nevertheless provide insights into what barriers are preventing people from broader adoption of PrEP, including topics that are specific to two different groups of sexual minorities and racial and ethnic minority populations. Results have the potential to inform future health promotion and regulatory science approaches that can reach these HIV/AIDS communities who may benefit from PrEP.