Mangale et al. Implementation Science Communications (2023) 4:95 https://doi.org/10.1186/s43058-023-00446-y RESEARCH Open Access © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativeco mmons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Implementation Science Communications Characterizing provider-led adaptations to mobile phone delivery of the Adolescent Transition Package (ATP) in Kenya using the Framework for Reporting Adaptations and Modifcations to Evidence-based Implementation Strategies (FRAME-IS): a mixed methods approach Dorothy Imbuka Mangale 1* , Alvin Onyango 2 , Cyrus Mugo 2,3 , Caren Mburu 1 , Nok Chhun 1 , Dalton Wamalwa 4 , Irene Njuguna 1,2 , Arianna Rubin Means 1 , Grace John-Stewart 1,3,5,6 , Bryan J. Weiner 1,7 and Kristin Beima-Sofie 1 Abstract Background The COVID-19 pandemic resulted in disruptions to routine HIV services for youth living with HIV (YLH), provoking rapid adaptation to mitigate interruptions in care. The Adolescent Transition to Adult Care for HIV- infected adolescents (ATTACH) study (NCT03574129) was a hybrid I cluster randomized trial testing the effectiveness of a healthcare worker (HCW)-delivered disclosure and transition intervention — the Adolescent Transition Package (ATP). During the pandemic, HCWs leveraged phone delivery of the ATP and were supported to make adaptations. We characterized real-time, provider-driven adaptations made to support phone delivery of the ATP. Methods We conducted continuous quality improvement (CQI) meetings with HCWs involved in phone delivery of the ATP at 10 intervention sites. CQI meetings used plan-do-study-act (PDSA) cycles and were audio-recorded. Adaptations were coded by two-independent coders using the Framework for Reporting Adaptations and Modi- fications to Evidence-based Implementation Strategies (FRAME-IS). Adaptation testing outcomes (adopt, retest, or abandon) and provider experience implementing the adaptations were also recorded. We summarized adaptation characteristics, provider experience, and outcomes. Results We identified 72 adaptations, 32 were unique. Overall, adaptations included modification to context (53%, n = 38), content (49%, n = 35), and evaluation processes (13%, n = 9). Context adaptations primarily featured changes to personnel, format, and setting, while content and evaluation adaptations were frequently achieved by simple additions, repetition, and tailoring/refining of the phone delivery strategy. Nine adaptations involved abandoning, then returning to phone delivery. HCWs sought to increase reach, improve fidelity, and intervention fit within their *Correspondence: Dorothy Imbuka Mangale dmangale@uw.edu Full list of author information is available at the end of the article