KKKristian van Kalmthout

Kristian van Kalmthout

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Kristian van Kalmthout has a total of 44 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Engagement With Digital Adherence Technologies as Measures of Intervention Fidelity Among Adults With Drug-Susceptible Tuberculosis and Health Care Providers: Descriptive Analysis Using Data From Cluster-Randomized Trials in Five Countries

    by Jason Alacapa, Amare Worku Tadesse, Natasha Deyanova, Tanyaradzwa Dube, Andrew Mganga, Rachel Powers, Job van Rest, Norma Madden, Egwuma Efo, Salome Charalambous, et al.

    Background: Digital adherence technologies (DATs) are promising tools for supporting tuberculosis (TB) treatment. DATs can serve as reminders for people with TB to take their medication and act as proxies for adherence monitoring. Strong engagement with DATs, from both the person with TB and health care provider (HCP) perspectives, is essential for ensuring intervention fidelity. The Adherence Support Coalition to End TB (ASCENT) project evaluated 2 types of DATs, pillboxes and medication labels (99DOTS), in cluster-randomized trials across 5 countries. Objective: This study aims to investigate participant and HCP engagement with DATs for TB treatment, stratified by DAT type and country. Methods: This study is a subanalysis of data generated through the ASCENT trials, which enrolled adults with drug-susceptible TB. A digital dose was defined as either a pillbox opening (for pillbox users) or a dosing confirmation SMS text message sent by the participant (for label users), both of which were recorded on the adherence platform. Descriptive analysis was used to provide an overview of dose-day outcomes. DAT engagement was assessed from both participant and HCP perspectives. To enhance participant engagement, we summarized the frequency of digital engagement overall and by treatment phase, as well as the frequency of consecutive days without engagement. For HCP engagement, we summarized the frequency of doses added manually, the number of days between the actual dose day and when a manual dose was added, and instances of consecutive manual dosing lasting more than 3 and more than 7 days, where doses were added more than 1 week after the dose day. Results: Of the 9511 participants included, 6719 (70.64%) were using the pillbox, 3544 (37.26%) were female, and the median age was 40 years. Across DAT types, there were 1,384,879 dose days, with 973,876 (70.32%) contributed by pillbox users. Of all dose days, 1,165,195 (84.14%) were recorded as digital, 156,664 (11.31%) as manual, 59,045 (4.26%) had no information, and 3975 (0.29%) were confirmed as missed. Digital dosing decreased slightly from the intensive to the continuation phase. The percentage of digital dose days was higher among pillbox users (851,496/973,876, 87.43%) compared with label users (313,699/411,003, 76.33%). Among label users, manual dosing was most common in the Philippines (37,919/171,786, 22.07%) and least common in Tanzania (11,108/76,231, 14.57%). Among pillbox users, manual dosing was most common in the Philippines (24,015/208,130, 11.54%) and Ukraine (13,209/111,901, 11.80%). Overall, 512 out of 2792 (18.34%) label users and 588 out of 6719 (8.75%) pillbox users experienced a run of more than 7 consecutive nondigital dose days that were resolved more than 1 week after the dose day. The highest occurrence was observed in the Philippines (368/1142, 32.22%, for label users and 224/1351, 16.58%, for pillbox users). Conclusions: There was considerable variation in DAT engagement across countries and DAT types, reflecting differences in how the intervention was implemented. Further refinement of the intervention and improvements in its delivery may be necessary to enhance outcomes.


  • Open Access

    Process Evaluation of Pragmatic Cluster-Randomized Trials of Digital Adherence Technologies for Tuberculosis Treatment Support: A Mixed-Method Study in Five Countries

    by Norma Madden, Amare W. Tadesse, Chung Lam Leung, Bianca Gonçalves Tasca, Jason Alacapa, Natasha Deyanova, Nontobeko Ndlovu, Nontobeko Mokone, Baraka Onjare, Andrew Mganga, et al.

    Digital adherence technologies (DATs) could improve the person-centeredness of tuberculosis (TB) treatment. DATs are found to be acceptable, though evidence of their effectiveness is varied. Our objective was to understand the fidelity of DAT interventions within five cluster-randomized trials. Two DATs (smart pillbox, medication labels) were assessed, with real-time adherence data available to healthcare providers (HCPs) on a digital platform in Ethiopia, the Philippines, South Africa, Tanzania, and Ukraine. A framework assessed four components of implementation: inputs (training, support, mobile access), processes (SMS, home visits, platform usage), outputs (DAT engagement, manual dosing), and outcomes (people with TB (PwTB)–HCP relationship). Fidelity was evaluated by quantitative indicators, and content analysis of qualitative sub-studies supplemented some indicators. Engagement with DATs was high among PwTB. Pillbox users showed high levels of sustained engagement (box opening), with digitally recorded doses ranging from 82% to 91%. Differences were observed in login frequency by HCPs to the adherence platform. In Ethiopia, Tanzania, and Ukraine, there was at least one login to the platform on 71% of weekdays per facility compared with the Philippines and South Africa at 42% and 52%, respectively. Intervention fidelity varied among countries, suggesting a need for future work on optimizing implementation.


  • Open Access

    Modelling the epidemiological and economic impact of digital adherence technologies with differentiated care for tuberculosis treatment in Ethiopia

    by Lara Goscé, Amare Worku Tadesse, Nicola Foster, Kristian van Kalmthout, Job van Rest, Jense van der Wal, Martin J Harker, Norma Madden, Tofik Abdurhman, Demekech Gadissa, et al.

    Background: Digital adherence technologies (DATs) with associated differentiated care are potential tools to improve tuberculosis (TB) treatment outcomes and reduce associated costs for both patients and healthcare providers. However, the balance between epidemiological and economic benefits remains unclear. Here, we used data from the ASCENT trial to estimate the potential long-term epidemiological and economic impact of DAT interventions in Ethiopia. Methods: We developed a compartmental transmission model for TB, calibrated to Ethiopia and parameterised with patient and provider costs. We compared the epidemiological and economic impact of two DAT interventions, a digital pillbox and medication labels, to the current standard of care, assuming each was introduced at scale in 2023. We projected long-term TB incidence, mortality and costs to 2035 and conducted a threshold analysis to identify the maximum possible epidemiological impact of a DAT intervention by assuming 100% treatment completion for patients on DAT. Findings: We estimated small and uncertain epidemiological benefits of the pillbox intervention compared with the standard of care in Ethiopia, with a difference of −0.4% (95% uncertainty interval (UI) −1.1%; +2.0%) incident TB episodes and −0.7% (95% UI −2.2%; +3.6%) TB deaths. However, our analysis also found large total provider and patient cost savings (US$163 (95% UI US$118; US$211) and US$3 (95%UI: US$1; US$5), respectively, over 2023–2035), translating to a 50.2% (95% UI 35.9%; 65.2%) reduction in total cost of treatment. Results were similar for the medication label intervention. The maximum possible epidemiological impact a theoretical DAT intervention could achieve over the same timescale would be a 3% (95% UI 1.4%; 5.5%) reduction in incident TB and an 8.2% (95% UI 4.4%; 12.8%) reduction in TB deaths. Interpretation: DAT interventions, while showing limited epidemiological impact, could substantially reduce TB treatment costs for both patients and the healthcare provider.


  • Open Access

    Digital Adherence Technologies and Differentiated Care for Tuberculosis Treatment and Their Acceptability Among Persons With Tuberculosis, Health Care Workers, and Key Informants in the Philippines: Qualitative Interview Study

    by Chung Lam Leung, Jason Alacapa, Bianca Gonçalves Tasca, Andre Daniel Villanueva, Saniata Masulit, Marvin Louie Ignacio, Kathleen Nicole Uy, Christopher Pell, Kristian van Kalmthout, Rachel Powers, et al.

    Background: Digital adherence technologies (DATs) are being studied to determine their potential to support tuberculosis (TB) treatment and address the shortcomings of directly observed therapy. Previous research has shown inconclusive results on whether DATs can enhance medication adherence among persons with TB. Objective: This study aims to understand the acceptability of DATs, namely, medication labels and smart pillboxes, among persons with TB, health care workers (HCWs), and key informants (KIs) in the Philippines. The objective is to gain valuable insights that can inform the design and implementation of DATs in the Southeast Asian region, which meet the needs and preferences of end users. Methods: Persons with TB, HCWs, and KIs were recruited from intervention facilities to participate in in-depth interviews conducted between March 2022 and January 2023. These interviews were transcribed and translated into English. A thematic analysis was carried out using NVivo software (Lumivero) to identify and analyze themes. Themes were then structured within a modified social-ecological model. Results: A total of 25 persons with drug-sensitive TB and 20 HCWs or KIs were interviewed. Both groups emphasized that users’ technology literacy level, financial conditions, and motivation to be cured determined how they interacted with the DAT. They also acknowledged that DATs helped foster their relationship with HCWs and enabled efficient treatment support. Concerning technology, persons with TB found DATs easy to use and able to reduce clinic visits. HCWs mentioned that DATs added to their workload but also allowed them to support users who missed doses. However, both groups experienced technical challenges with DATs. Regarding program implementation, users appreciated the clear explanations and demonstrations provided by HCWs. Yet, some users reported inconsistencies between DAT settings and the information provided. HCWs stressed the importance of comprehensive training and sufficient resources for effective program implementation in the future. At the community level, both groups noted that DATs and program design protected users’ privacy and reduced the risk of stigma. Finally, users and HCWs shared various contextual factors that influenced their experience with DAT, including infrastructure challenges and the impact of the COVID-19 pandemic. Conclusions: In the Philippines, persons with TB and HCWs showed a high level of acceptance and satisfaction with the impact of DAT and program design. They expressed a desire for the continuation of DATs. The challenges encountered underscore the need for ongoing technological development to minimize malfunctions, enhance the capacity of health facilities, and improve infrastructure. DATs have demonstrated their ability to strengthen user-HCW relationships and protect users from stigmatization. Additional efforts are required to scale up the DAT program in the Philippines.


  • Open Access

    Factors Related to the Utilization of Digital Adherence Technologies in Tuberculosis Care: A Qualitative Study Among Adults in DS-TB Treatment, Health Care Providers and Other Key Stakeholders in Tanzania

    by Bianca Gonçalves Tasca, Andrew Mganga, Chung Lam Leung, Lucas Shilugu, Christopher Pell, Baraka Onjare, Nicholaus Luvanda, Liza de Groot, Kristian van Kalmthout, Katherine Fielding, et al.

    Numerous challenges, such as lengthy treatmenst courses, side effects, and distance to healthcare facilities contribute to suboptimal Tuberculosis (TB) treatment completion. Digital adherence technologies (DATs), such as smart pillboxes and medication labels, could be an alternative to facilitate TB treatment continuation. In-depth interviews with people undergoing treatment for drug susceptible TB, health care providers (HCPs) and other key stakeholders were conducted to evaluate their experiences with DATs in ten health facilities across four different regions in Tanzania. This study is part of a multi country cluster randomized trials conducted under the ASCENT consortium. Interviews were conducted with a total of 41 individuals, 19 people with TB and 22 HCPs and key stakeholders. One of the main findings indicates that participants found that the daily reminders provided by the DATs, particularly the alarm from the smart pillboxes, helped in supporting treatment continuation and establishing a routine around medicine intake. DATs use was linked with reducing the financial burden of treatment, improving people with TB-HCPs relationship, and decreasing workload for HCPs. Although DATs were generally perceived as reliable, occasional technical malfunctions, such as battery depletion in smart pillboxes, were reported. The requirement of having access to a cellphone and a power source emerged as specific barriers for medication label users. This study highlights the initial willingness and sustained enthusiasm for using DATs among respondents. DATs were perceived as useful tools, aiding individuals with treatment continuation through daily reminders and fostering stronger connections with HCPs. Nevertheless, issues such as poor network connectivity and the need for access to a working cellphone posed difficulties in usage. Findings from this study suggest the potential for improvements in the technologies and indicate that a thorough assessment of people’s life conditions and needs prior to treatment initiations is important to determine the suitability of providing a DAT.


  • Open Access

    Digital Adherence Technologies and Differentiated Care for Tuberculosis Treatment and Their Acceptability Among Persons With Tuberculosis, Health Care Workers, and Key Informants in the Philippines: Qualitative Interview Study (Preprint)

    by Chung Lam Leung, Jason Alacapa, Bianca Gonçalves Tasca, Andre Daniel Villanueva, Saniata Masulit, Marvin Louie Ignacio, Kathleen Nicole Uy, Christopher Pell, Kristian van Kalmthout, Rachel Powers, et al.

    BACKGROUND Digital adherence technologies (DATs) are being studied to determine their potential to support tuberculosis (TB) treatment and address the shortcomings of directly observed therapy. Previous research has shown inconclusive results on whether DATs can enhance medication adherence among persons with TB. OBJECTIVE This study aims to understand the acceptability of DATs, namely, medication labels and smart pillboxes, among persons with TB, health care workers (HCWs), and key informants (KIs) in the Philippines. The objective is to gain valuable insights that can inform the design and implementation of DATs in the Southeast Asian region, which meet the needs and preferences of end users. METHODS Persons with TB, HCWs, and KIs were recruited from intervention facilities to participate in in-depth interviews conducted between March 2022 and January 2023. These interviews were transcribed and translated into English. A thematic analysis was carried out using NVivo software (Lumivero) to identify and analyze themes. Themes were then structured within a modified social-ecological model. RESULTS A total of 25 persons with drug-sensitive TB and 20 HCWs or KIs were interviewed. Both groups emphasized that users’ technology literacy level, financial conditions, and motivation to be cured determined how they interacted with the DAT. They also acknowledged that DATs helped foster their relationship with HCWs and enabled efficient treatment support. Concerning technology, persons with TB found DATs easy to use and able to reduce clinic visits. HCWs mentioned that DATs added to their workload but also allowed them to support users who missed doses. However, both groups experienced technical challenges with DATs. Regarding program implementation, users appreciated the clear explanations and demonstrations provided by HCWs. Yet, some users reported inconsistencies between DAT settings and the information provided. HCWs stressed the importance of comprehensive training and sufficient resources for effective program implementation in the future. At the community level, both groups noted that DATs and program design protected users’ privacy and reduced the risk of stigma. Finally, users and HCWs shared various contextual factors that influenced their experience with DAT, including infrastructure challenges and the impact of the COVID-19 pandemic. CONCLUSIONS In the Philippines, persons with TB and HCWs showed a high level of acceptance and satisfaction with the impact of DAT and program design. They expressed a desire for the continuation of DATs. The challenges encountered underscore the need for ongoing technological development to minimize malfunctions, enhance the capacity of health facilities, and improve infrastructure. DATs have demonstrated their ability to strengthen user-HCW relationships and protect users from stigmatization. Additional efforts are required to scale up the DAT program in the Philippines.