Partial evaluation of fidelity in the implementation of tuberculosis preventive treatment in people living with HIV in Paraguay: an implementation science study

Abstract

Objectives. To evaluate self-reported adherence to the essential components of tuberculosis preventive treatment (TPT), as an estimate of partial implementation fidelity, and to explore the moderating factors influencing its implementation in two referral services in the Central Department, Paraguay. Materials and methods. A descriptive observational mixed-methods study with a convergent parallel design  (January–May 2023) was conducted in two referral  centers for people living with HIV. Partial  implementation fidelity was estimated through self-reported adherence to the content and frequency  dimensions of TPT implementation according to the  National Tuberculosis Guide. Semi-structured interviews were conducted with key stakeholders to identify  barriers and facilitators. Results. 11/13 physicians and 10 key stakeholders participated. Overall TPT fidelity was  low (50.0%). Adherence to content was moderate (64.2%), while adherence to frequency was low (31.3%), evidencing a gap between perceived importance and clinical practice. The awareness/education component showed the lowest performance. The main barriers were identified in the internal environment, including organizational fragmentation between TB/HIV  programs, limited resources, absence of operational  protocols, and communication deficiencies. At the  individual level, erroneous beliefs and low self-efficacy  were identified. As facilitators, national normative  alignment and the willingness of stakeholders to  strengthen implementation were observed. Conclusions.
Low fidelity reflects mainly organizational and process failures, which highlights the need for facilitation strategies, interprogrammatic articulation, and capacity strengthening to achieve sustained implementation.