The investigators propose to maintain patient safety while reducing the substantial VMMC follow-up workload burden by using two-way mobile phone texts to provide in-person review only for men who indicate a desire or need for follow-up. This tailored approach to post-procedure VMMC care could reduce unnecessary visits and remove barriers for VMMC clients without deterioration of quality care. ZAZIC's diverse, expert team of researchers from the University of Washington, Seattle, USA; the University of Zimbabwe; Medic Mobile, Nairobi, Kenya; and Zimbabwean partner organizations will test this mHealth intervention. The investigators believe that bi-directional, interactive, text-based short message service (SMS) during the most critical 14 days after circumcision will help men identify and act on any sign of an adverse event, thereby seeking in-person follow-up only when an AE is suspected and reducing unnecessary visits. Reduced in-person follow-up could also free healthcare workers to perform additional VMMC surgeries. Using a prospective, randomized control trial (RCT), our intervention compares two groups of clients with cell phones: 1) standard care (control group) and 2) clients who receive and respond to a daily text with in-person follow-up only if desired or if an AE is suspected (intervention). Both arms complete a study-specific, Day 14, in-person, follow-up review for verification of self-reports (intervention) and comparison (control). Our specific aims are to:

Aim 1: Determine if 2-way texting can safely reduce VMMC follow-up visits Approach: Un-blinded, prospective, non-inferiority, RCT in high-volume facilities providing VMMC. Two-way texting (2wT) will provide interactive, text-based follow-up. 2wT men healing without complication could decline in-person follow-up; those with suspected AEs will be referred to in-person care. The investigators will compare the safety outcome of combined moderate or severe AE rate ≤ Day 14 post-VMMC and the workload outcome of average number of in-person follow-up visits between control and intervention arms.

Aim 2: Estimate the cost savings associated with 2wT over routine VMMC follow-up Approach: The investigators will determine the programmatic costs of 2wT from a systems perspective, including the technology \[24\], healthcare worker costs, and client perspective. The investigators will estimate the incremental intervention costs relative to standard practice to quantify gains in healthcare efficiency for scale-up and adoption.

Aim 3: Assess the acceptability and feasibility of 2wT for further scale-up Approach: Qualitative interviews with VMMC healthcare workers and brief quantitative interviews with 2wT clients inform intervention acceptance. Meetings with local researchers and collaborators will further assess feasibility, adaptation, open-source collaborative development, and system integration for replication and sustainability in Zimbabwe and the region.

APPROACH Study overview: Following usability testing with both healthcare workers and 2wT VMMC clients, The investigators will test if two-way texting (2wT) reduces unnecessary follow-up visits without compromising patient safety (Aim 1) using a randomized control trial in large, urban VMMC clinics. The investigators will assess the costs of 2wT from technology, healthcare worker, and client perspectives to determine the costs incurred by MoHCC if adopted for scale-up (Aim 2). The investigators will assess acceptability and feasibility working towards system integration and sustainability in Zimbabwe and beyond (Aim 3).

Aim 1: Technology overview: Studies that demonstrate the impacts of mHealth interventions too often have evaluated technologies that are made 'from scratch' and as a result are not robust enough to merit widespread replication \[48, 74\]. By partnering with a well-established non-profit mHealth organization, Medic Mobile (http://medicmobile.org/), and integrating with their existing software platform, open-source community and current efforts to integrate with existing health information systems (HIS) throughout sub-Saharan Africa, our team and proposed intervention are well positioned to scale up and sustain any promising results. Since 2008, Medic Mobile has been a leader in the global mHealth community \[75-77\], equipping more than 13,500 health workers serving over 8 million people across 23 countries. The Mobile Medic Toolkit is an Android-based application that supports texting in any language and works with or without internet connectivity on basic phones, smartphones, tablets, and computers \[78\]. The existing, well-proven, app-based Toolkit that will be the basis for 2wT provides an automated and prioritized list of upcoming tasks, guiding health worker through actions (e.g., response waiting, referral). The Toolkit provides real-time progress indicators such as texting delivery rates and response rates. Data from mobile users are replicated to Medic Mobile web app and analytics tools for real-time response. The platform is highly configurable, currently supporting evidence-backed workflows and program implementation related to ensuring safe deliveries \[79\], tracking tuberculosis patients \[80\], boosting immunization rates \[81\] and monitoring stocks of essential medicines \[82\]. These adaptable tools are free, open-source, and developed using human-centered design with input from people delivering care in the hardest-to-reach communities. While this technology has never been used in a VMMC program and requires adaptation of the clinical content, the existing 2wT software toolkit already contains the robust messaging features discussed in this proposal (Figure 2). The software adaptation process to alter and test alternative clinical content and the local specifications requires little additional software development. The adaptation process will be completed by co-investigator, Holeman, with additional technical and training support provided by Nairobi-based technical experts.

Study sites and population: In Zimbabwe, 81% of people already had mobile phone subscriptions in 2014 \[83\], indicating that the technology infrastructure exists and uptake is high. 2wT will be implemented in existing VMMC sites in the Chitungwiza District, a district purposefully selected for its high VMMC volume clinic locations. Chitungwiza District, a suburb of Harare, has an estimated 300,000 eligible, HIV-negative men ages 15-29; only 14% of eligible men have been circumcised to date. The investigators will implement 2wT in up to 5 ZAZIC VMMC sites in Chitungwiza, sites averaging 50-200 VMMC/month. About 80% of VMMC clients are surgical, rather than PrePex device-based, clients.

Study preparation: The investigators will conduct a rapid situation analysis with healthcare workers, VMMC clients, and stakeholders to assess suitable responses to VMMC client texts, setting standards for text responses and in-person follow-up. The investigators will modify existing usability surveys for this public health context. A small pilot with 50 VMMC clients will include usability testing with both 2wT clients and nurses implementing the 2wT system, illuminating system experiences from both perspectives. Usability results will inform in-box modification, message format preferences (SMS or WhatsApp) and optimal message delivery (timing, frequency, language preferences). Experience from study coordinator and other team members will add detail to inform 2wT adaptation and modification of Standard Operating Procedures before implementation. The investigators will examine local infrastructure (e.g. electricity and cell network), and explore 2wT cost reduction options (e.g., text bundling, free-call back numbers) and adapt accordingly

Standard VMMC care (Control arm): ZAZIC follows all MoHCC protocols based on WHO guidelines \[20\] including routine surgical VMMC follow-up on post-surgery days 2, 7 and 42 (Table 1). Patients may seek care outside scheduled visits for suspicion of AEs at any healthcare facility at any time but most often return to their VMMC site. Referral cards for VMMC clients provide local numbers for patients to text, call, or request a call back for emergencies. A standardized approach is used to assess, identify, and record the severity of AEs \[51\]. All VMMC care, from assessment of all AEs through complete healing, is provided free to clients from MoHCC. Clients who do not return to the clinic for follow-up on Day 2 or Day 7 are traced: 3 attempts by phone and then up to 3 attempts at in-person tracking after which they are considered lost to follow-up (LTFU) \[52\]. There is no tracing for Day 42 visits. For the purposes of this study, control arm VMMC clients will be asked to come in on Day 14 for an additional follow-up visit. No active follow-up is provided at Day 14.

VMMC care procedures (2wT arm): The investigators will conduct a prospective, un-blinded, randomized control trial (RCT) among VMMC clients in a 1:1 ratio of control to intervention. Study participants and clinic staff are not masked to treatment. Men in the 2wT will receive routine VMMC surgical care and counseling, including referral cards for emergencies. 2wT clients will receive automated daily texts from days 1-14 (Table 1 and Figure 3). It is free to receive call and texts; it costs $0.05 to send a SMS in Zimbabwe \[84\]. If they respond that they suspect no adverse event, no immediate follow-up action will be taken. If a 2wT VMMC client responds affirmatively to any daily text that he suspects an AE, a VMMC nurse will exchange modifiable, scripted texts with the client to determine the symptoms, frequency, and severity. Then, if deemed necessary, the client will be asked to return to clinic the following day or earlier if an emergency is suspected. AE management will adhere to MoHCC standard care. If 2wT patients do not respond to texts on Day 2 or Day 7, the same MoHCC tracing process will be activated, after which they will be considered LTFU. All study participants will be asked to come to the clinic for study-specific, Day 14 follow-up to review healing and verify adverse event reporting. Day 14 was chosen for verification because 95% of all AEs within the ZAZIC VMMC program are reported Day 14 or earlier \[50\], suggesting that most AEs have occurred by this time point. In a previous field study of AEs, the most common AEs of bleeding and infection were found a mean of 6.7 and 9.0 days, respectively, after VMMC \[29\], further supporting the 14 day period used in this and a previous study\[5\]. The Day 14 review will be conducted by routine VMMC providers according to MoHCC review guidelines. At Day 42, The investigators will implement a brief text-based survey with 2wT clients to ascertain complete healing, providing stronger inferences at study completion.