The goal of this feasibility study is to co-create and evaluate a theory informed, evidence-based, patient-centered healthbot aimed at helping people adhere to their varenicline regimen. The main research questions it aims to answer are:

1. What are the challenges to varenicline adherence and strategies to overcome such challenges from the perspective of service users and service providers?

2. What features of a healthbot would help improve adherence to varenicline?

3. Does a healthbot developed to improve varenicline adherence meet the implementation outcomes and increase medication adherence as well as smoking cessation? The study will be conducted using the Discover Design Build and Test framework.

   • In the Discover phase, a literature review, 20 service user interviews, and 20 healthcare provider interviews will help inform the challenges to varenicline adherence, strategies to overcome them using the Capability, Opportunity, Motivation, and Behavior framework, and the ways in which a healthbot might help improve adherence.
   • In the Design, Build and Test phase, 40 participants will interact with a preliminary healthbot using the Wizard of Oz method, then provide feedback about their experiences in a follow up interview; and team members, including clinicians and researchers, will beta test and validate a more refined healthbot.

In the last phase, a non-randomized single arm feasibility study, 40 participants will interact with the healthbot for 12 weeks and provide feedback about the acceptability, appropriateness, fidelity, adoption, and usability of the healthbot; and researchers will assess participants' medication adherence and smoking status.

A: Co-design a theory informed healthbot to support patients' adherence to varenicline:

The investigators will employ a user-centred approach to build the healthbot in order to optimize user experience and achieve the best uptake and utilization. Following the Discover, Design and Build, and Test (DDBT) framework, the investigators will use a three-step approach to co-design the core functionality of the healthbot: 1) review the literature and conduct interviews with potential users (Discovery Phase); 2) design the healthbot and conduct Wizard of Oz testing (Design/Build Phase); 3) Train and test the healthbot (Test Phase).

Literature review:

The aim of this rapid review is two folded: 1) to identify the barriers and facilitators to varenicline adherence, in people using varenicline for smoking cessation (the investigators will use the Theoretical Domains Framework (TDF) to organize the data extraction), and 2) to identify the behaviour change techniques (BCTs) that are associated with helping people adhere to their varenicline treatment (the investigators will use BCTT v1. to organize the data extraction). The study was registered with PROSPERO (# CRD42022321838).

Semi-Structured Interviews with people who use varenicline:

To gain in-depth understanding of the challenges and solutions people who use varenicline encounter and to understand what features users would like to see in a healthbot designed to help adhere to varenicline.

Semi-Structured Interviews with health care providers who help people who want to quit smoking:

There is little guidance regarding health care providers' (HCP) perspectives in recommending digital health solutions to their patients. Understanding the perspectives of HCPs is crucial to facilitate the effective delivery and uptake of the healthbot. These interviews will explore: (1) barriers/facilitators influencing HCPs provision of digital health solutions to patients prescribed varenicline; (2) Identify theoretical domains to target for behaviour change; (3) Select BCTs to include in the healthbot.

Wizard of Oz Method:

The purpose of this stage is to test a minimum viable product to determine whether the product needs a pivot. Pivots are structured improvements designed to test new fundamental hypotheses about products, strategies, and growth engines and often occur in the early stages of product development. The Wizard of Oz (WoZ) method is a popular approach wherein research participants interact with a computer system they believe is autonomous; however, responses are actually generated by an unseen human being (the wizard). It is useful in iterative development as it is very easy to change and evolve the wizard's responses.

Building the healthbot (Build Phase):

Following guidance from the Nonadoption, abandonment, scale-up, spread, and sustainability (NASSS) framework, the investigators will build the healthbot choosing the simplest sensible solution for the design. For this study, the investigators will build a rule-based healthbot, that has capabilities to determine the meaning of users' words. The rules will come from the literature review, the interviews, and WoZ testing. Specifically, following the discovery phase, the research team will rate all BCTs identified as possible contributors to helping people adhere to their varenicline based on whether it is affordable, practical, effective, acceptable, safe and equitable (APEASE criteria).

Training and testing (Test Phase):

The interviews and WoZ data will serve to help train the healthbot. In addition, once the investigators have a working prototype of the healthbot, team members including clinicians and researchers will interact with the healthbot to beta test and validate it.

B: Evaluate the implementation outcomes; examine medication adherence and smoking cessation success among participants who use the healthbot:

The investigators will conduct a non-randomized single arm feasibility study. It will only have an intervention group (with no control group) and is designed to examine important study procedures (e.g., patient recruitment, retention, missing data), in advance of a larger randomized controlled trial (RCT) testing the effectiveness of the healthbot.

Interested individuals will contact research staff, who will explain the study and assess for inclusion criteria. If eligible, participants will be sent a consent form and scheduled for a phone-based consent discussion. Once consent is received, an in person or virtual baseline visit will be scheduled where participants (n=40) will be asked a few baseline questions related to socio-demographic characteristics, smoking dependency, and an adapted scale to measure varenicline adherence self-efficacy. They will have a virtual or in person visit with a healthcare provider for eligibility confirmation and obtain a prescription for varenicline for the first four weeks (one tablet [0.5 mg] daily for the first three days, one tablet [0.5 mg] twice daily for the next four days, and one tablet [1 mg] twice daily for three weeks). In addition, research staff will show participants how to use the healthbot on their phones. A follow up visit will be scheduled at two weeks where healthcare providers will assess the participant's tolerance of varenicline and provide a prescription for the remaining eight weeks (one tablet (1 mg) twice daily or a different dose depending on the tolerance of each participant). Medication will be provided in person or mailed to the participants based on the format of their baseline and follow up healthcare provider visit. Any unanticipated problems due to varenicline use (i.e., adverse events that are unexpected in terms of severity, nature or frequency; related, or possibly related to participation in the research; and suggest that the research places other research participants at greater risk of harm) will be documented as applicable and reported to the Research Ethics Board and adverse drug reactions will be reported to the Market Authorization Holder (APOTEX) as applicable.

The healthbot will provide: 1) reminders for varenicline dosing and schedule; 2) information and suggestions on managing known side effects (the most frequently cited reason for varenicline non-adherence is experiencing side effects); 3) answers to questions about medication use (e.g., what to do if a dose is missed); 4) tracking medication intake and smoking; 5) support and encouragement to increase participants' motivation to continue their quit attempts. During the next 12 weeks, participants will be reminded by the healthbot to take their varenicline at the appropriate times and will be able to interact with the healthbot when they want.

At 1, 4, 8, and 12 weeks, participants will complete a survey. All participants who do not complete the follow-up survey within the timeframe allowed will be contacted by phone from research staff. In addition, after the 12 weeks of using the healthbot, participants will participate in a 1-hour semi-structured phone interview.

Inclusion Criteria:

• Treatment-seeking smokers who are willing to start taking varenicline and continue it for 12 weeks, and set a quit date in the next 30 days;
• Smoke cigarettes daily (10 or more cigarettes a day)
• Age ≥ 18 years;
• Speak/read English;
• Have a smartphone with data plan;
• Report being committed to answering questions during follow-up;
• Live in Ontario.

Exclusion Criteria:

• Have contraindication(s) to varenicline use;
• Are pregnant/planning to become pregnant/breastfeeding;
• Participated in the co-design phase.

12 weeks

Adverse events were monitored throughout the study.