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Potential Role of Conversational Agents in Encouraging PrEP Uptake

Approximately 1.2 million people are living with HIV, with many of them unaware of their infection. Pre-exposure prophylaxis (PrEP) is available to minimize transmission among those at high risk for infection, including men who have sex with men, people who inject drugs, and female sex workers. Despite its availability, there is low usage of PrEP. To address this problem, various digital tools have been examined in HIV research. Among those, conversational agents are still underused and their capacity warrants examination to reach at-risk populations. In this paper, we discuss the potential of conversational agents in increasing uptake of PrEP by addressing barriers experienced among those at high risk for infection.

For persons who inject drugs, uptake is also hindered by limited access and negative experience with healthcare and criminal justice system. 6,8,9 In addition to the previously mentioned barriers, cost is also a limiting factor to PrEP uptake among various low-income populations, including adolescents 10 and female sex workers. [11][12][13][14] In light of low uptake of PrEP, this paper explores the use of conversational agents in providing information to those at high risk and encourages uptake of PrEP.

Digital Tools and Conversational Agents
Digital tools, such as mobile applications, electronic health records, and telemedicine often incorporating artificial intelligence and geolocation, have been used in promoting HIV prevention and PrEP uptake for at-risk populations. [15][16][17][18][19] Conversational agents, a type of digital tool, can be in the form of chatbots or virtual assistants (e.g., Alexa, Siri), designed to mimic human-like textual or verbal communications. Simple chatbots and virtual assistants use keywords and pre-defined answers while smart chatbots benefit from natural language processing (NLP) approaches when communicating with the users. 20,21 NLP, a branch of artificial intelligence, affords computer systems the ability to understand natural human speech patterns, as well as the meaning and context of the message. NLP can interact with human users through text or voice interface. 22,23 Examples of NLP include Amazon's Alexa, Apple's Siri, 24 and smart chatbots.
More than 70% of consumers were satisfied with virtual assistants (i.e., Siri), using them for researching, making purchases, and other functions. Between 2018 and 2019, twice as many consumers stated in surveys that they would knowingly engage with chatbots. 25 Smart speakers with digital voice assistants such as Alexa and Siri continue on an upward trend. 26 Consumer uses for virtual assistants include requesting information, entertainment, customer service, retail purchase and payment, and controlling smart home devices. 27 To date, 1.4 billion people use chatbots on a regular basis, and as an example, there were over 300,000 chatbots on Facebook alone in 2018. 28 Conversational agents, often based on artificial intelligence, are already being explored for use in HIV prevention. 29 Examples of the use of conversational agents for HIV can be found in both research and health agencies. Conversational agents in the form of virtual assistants are suggested to have great potential for promoting HIV testing by offering pre-testing counseling, providing a directory of online home test kit vendors and nearby testing locations, and placing HIV test kits in a shopping cart or subscription service. 30 In one study, virtual assistants were evaluated on the accuracy of the derived information about PrEP for HIV prevention when targeting adolescents and young adults. 31 In 2017, investigators used a chatbot on Facebook messenger to deliver information about HIV/ AIDS. 32 Other researchers used conversational agents to encourage uptake of HIV testing and were well received by users. 33,34 A chatbot was developed by the United Nations Educational, Scientific and Cultural Organization Institute for Information Technologies in Education to provide youth with information about relationships, family, health, and sex and was positively received by the public in 2020. The chatbot was also an avenue to open a dialogue about HIV prevention, testing, and treatment. 35 With regard to PrEP, researchers examined the feasibility of a mobile application (app) to increase PrEP adherence among young men who have sex with men (MSM), between 2018 and 2020. The AI-based app was successful in reaching a 91% adherence rate among users and was rated positively by study participants. 18 Although there has been a lot of research on using conversational agents in health domains, there has been no known study to investigate the use of conversational agents in addressing barriers to PrEP uptake. Conversational agents may hold great potential to be used in promoting PrEP uptake and HIV prevention. Some of the benefits of using conversational agents in PrEP uptake are being able to have dynamic back and forth conversations, being able to provide verified correct information, ensuring scalability, and ability to have machines rapidly provide and distribute information to a large group of people.

PrEP, Barriers, and Conversational Agents
Stigma, provider bias, and distrust of healthcare system Labeling, stereotyping, and rejection are among different forms of PrEP-related stigma 36 among those at high risk who may experience when seeking help in healthcare system, which works as a barrier to PrEP uptake. Using conversational agents such as chatbots or virtual assistants to gather information about PrEP may remove these limitations by those who would most benefit from PrEP. Users may be more comfortable communicating with conversational agents instead of providers who they feel might otherwise judge them for requesting PrEP. A similar approach has been used in a study to promote deep self-disclosure, in which participants stated feeling more comfortable sharing with the chatbot rather than the mental health professional when it comes to deeper levels of feelings and thoughts. 37

Knowledge and risk perception
Insufficient knowledge, questions, or concerns regarding PrEP can cause misconception in both healthcare providers and at-risk populations. 38 Lack of knowledge and misconceptions may be addressed by conversational agents through programmed information that is science-based. Information provided by conversational agents may be able to counter myths or misinformation that those at high risk may encounter online or on social media. To obtain accurate information about PrEP, using chatbots on social media messengers or mobile health applications might be more convenient compared to calling or emailing healthcare providers or waiting for the next clinic visit. Chatbots and virtual assistants can provide information in a more conversational manner that may be more appealing to some users compared to health or medical websites.
Also, some at-risk individuals might perceive their own true risk to be low, creating another barrier to PrEP uptake. 6 In addition to basic information about PrEP, conversational agents may be programmed to address risk misperceptions through recognition of keywords and NLP algorithms to encourage those at high risk to seek the advice of a healthcare professional. This is among the reasons why conversational agents, using keywords and NLP approaches, might be preferred to text message informational campaigns that can only provide back and forth, fixed communications.

Advantages of using conversational agents
Conversational agents can be implemented/integrated in websites, social media, phone applications, and other messaging platforms and easily expanded to reach larger populations. This also makes them more accessible for a wide range of people. Conversational agents can provide users with a personalized response. They have the potential to be faster in comparison to emails and phone calls. Conversational agents also have potential to be programmed to use accurate information from credible sources and eliminate the distribution of misinformation. Table 1 presents a comparison between conventional mediums and conversational agents regarding PrEP, based on the following factors: • Multi-platform: covering different platforms such as mobile applications, social media, websites, and smart speakers or being accessible from various devices such as mobile and computer • Personalized response: providing tailored responses according to the user's question • Fast response: time spent to communicate with the medium and get a response (immediate response is preferred) • Accurate information: providing the user with science-based and correct response • Scalable: the extent medium can reach the target population at once and distribute information • Input/output modality: methods of communication with the user • Trust and privacy: available regulations to protect the user data Although conversational agents are not a one-size-fits-all solution, and cannot overcome barriers such as PrEP cost, they may be able to address some of the limitations of features provided by the conventional mediums, for example, by responding with accurate, verified information in-time to the stigmatized population through text or voice and promote PrEP uptake.

Limitations to use of conversational agents
Novel use of existing digital tools is not without limitations. In one study, participants reported that the chatbot they engaged with replied too quickly, had speech patterns that were overtly formal, and occasionally misunderstood them. 33 In a mental health study using conversational agents, participants noted limited conversational responsiveness and that the conversational agent exhibited negative personality traits. Participants also suggested that lack of trust in the app programmer might be a barrier to using conversational agents. 39 Other users may have privacy concerns that would inhibit them from using conversational agents. As technologies continue to evolve, there is much that can be improved in conversational agents, including regulations to assure user privacy.

Conclusion
The increasing popularity and use of conversational agents in the community introduces a novel use of this technology in research and clinical practice. Chatbots and virtual assistants may offer an important service to help mitigate transmission of HIV by addressing barriers that those at high risk for infection experience. Conversational agents may be programmed to provide information about PrEP and address myths and misinformation that would otherwise inhibit uptake. As a

Implications for Behavioral Health
It is important that chatbots focused on PrEP are delivered and implemented using proper social and behavioral science theory 40 to increase the likelihood of a successful implementation. Tailoring the PrEP-related chatbots for the target population, such as men who have sex with men, may have an impact on increasing the uptake of PrEP via chatbots.
Conversational agents are digital tools that have potential use in uptake of preventive medications for HIV infection. As the use of chatbots and virtual assistants increases, conversational agents may be useful in providing information to the public, most especially key populations who are at high risk for HIV infection and who may experience barriers to uptake of PrEP. The ability to obtain factual information, without judgment, may encourage behavioral changes to minimize risk of infection.
Chatbots are increasingly being used in general online life. For example, there are chatbots being used on popular sites such as Facebook that allow people to interact with a chatbot and get health information while browsing Facebook. The WHO has used Facebook as the platform for its Health Alert chatbot which provides instant and accurate information about Covid-19. 41 We encourage HIV researchers to explore the potential of these types of approaches in the use of conversational agents and PrEP.