Date Published: January 16, 2019
Publisher: Public Library of Science
Author(s): Ferdinand C. Mukumbang, Brian van Wyk, Sara Van Belle, Bruno Marchal, Amrita Daftary.
Although empirical evidence suggests that the adherence club model is more effective in retaining people living with HIV in antiretroviral treatment care and sustaining medication adherence compared to standard clinic care, it is poorly understood exactly how and why this works. In this paper, we examined and made explicit how, why and for whom the adherence club model works at a public health facility in South Africa.
We applied an explanatory theory-building case study approach to examine the validity of an initial programme theory developed a priori. We collected data using a retrospective cohort quantitative design to describe the suppressive adherence and retention in care behaviours of patients on ART using Kaplan-Meier methods. In conjunction, we employed an explanatory qualitative study design using non-participant observations and realist interviews to gain insights into the important mechanisms activated by the adherence club intervention and the relevant contextual conditions that trigger the different mechanisms to cause the observed behaviours. We applied the retroduction logic to configure the intervention-context-actor-mechanism-outcome map to formulate generative theories.
A modified programme theory involving targeted care for clinically stable adult patients (18 years+) receiving antiretroviral therapy was obtained. Targeted care involved receiving quick, uninterrupted supply of antiretroviral medication (with reduced clinic visit frequencies), health talks and counselling, immediate access to a clinician when required and guided by club rules and regulations within the context of adequate resources, and convenient (size and position) space and proper preparation by the club team. When grouped for targeted care, patients feel nudged, their self-efficacy is improved and they become motivated to adhere to their medication and remain in continuous care.
This finding has implications for understanding how, why and under what health system conditions the adherence club intervention works to improve its rollout in other contexts.
The number of people living with HIV/AIDS (PLWHA) in South Africa has reached an estimated 7.9 million . Keeping in line with the ‘90-90-90’ goal (90% of all PLWHA knowing their HIV status, 90% of all people diagnosed with HIV infection receiving sustained antiretroviral therapy (ART), and 90% of all people receiving ART achieving viral suppression) by 2020 , South Africa has established various policies, programmes and strategies.
Realist evaluation is a theory-driven evaluation approach drawn from the seminal work of Pawson and Tilley . Realist evaluation starts by clarifying the ‘programme theory’–the set of assumptions of programme designers (or other actors involved) that explain how they expect the intervention to achieve its objective(s). The realist evaluator hypothesises the intervention, the relevant actors through whom the intervention is expected to work, the mechanisms that are likely to operate, the contexts in which the mechanisms might operate and the anticipated outcomes . This process is known as constructing the intervention-context-actor-mechanism-outcome (ICAMO) hypotheses [19,20] (Fig 1).
Within a realist evaluation, we applied an explanatory theory-building case study approach to testing the initial programme theory with the goal of refuting, validating or refining it. We adopted the multiple embedded case study design  with Facility X being one of the cases. Facility X was considered is a unit of analysis, with each of its adherence clubs being sub-units. Theory-testing using case studies evaluates the explanatory power of theories and their boundaries  so as to develop context-specific causal explanations of how and why programmes work . In realist logic, mechanisms–the process of how subjects interpret and act upon the intervention (or components of the intervention)–are at the heart of causal explanations  and the case study approach provides a platform to illuminate mechanisms in relation to outcomes.
Mitchell’s Plain is one of Cape Town’s largest townships established on the Cape Flats about 20 miles from the city centre in the mid-seventies as a ‘dormitory suburb’ for ‘Coloured’ people. The Mitchell’s plain township has about 290,000 inhabitants and comprises several sub-sections reflecting the diverse class backgrounds of the population.
The realist evaluation approach is method neutral, i.e. quantitative and qualitative data are collected as part of the programme theory that is being ‘tested’. The use of a multi-method evidence base to ensure good documentation of the implementation of the programme is encouraged . To this end, we collected and analysed quantitative and qualitative data.
This study is part of a larger project “A realist evaluation of the antiretroviral treatment adherence club programme in selected primary health-care facilities in the metropolitan area of Western Cape Province, South Africa”, which has received ethics clearance from the University of the Western Cape Research Ethics Committee (UWC REC) (Registration No: 15/6/28). In addition, we obtained ethical clearance from the Provincial Department of Health of the Western Cape Province. Furthermore, we obtained the permission of the facility head and management before data collection processes commenced.
The realist analysis process “is an ongoing iterative process of placing nuggets of information within a wider configurational explanation” . The data analysis proceeded in two steps: (1) separate analysis of the quantitative and qualitative components of the data and (2) synthesis of the findings from the quantitative and qualitative arms through configurational mapping using the ICAMO heuristic tool.
We first discuss the findings of the quantitative retrospective analysis, then the thematic analysis of the interviews and observation notes.
The retrospective descriptive analysis was used to describe the retention in care and adherence behaviours (principal outcomes) of the patients in the ART club. We used the Kaplan-Meier method  to describe the rate at which patients dropped out of club care (retention in care) and failed to maintained viral loads lower than detectable (≤400 copies/mL).
The results of the qualitative studies are presented, based on the framework provided by the two initial programme theories.
The above sections indicate how the interviews and observations yielded evidence in favour of many elements of the initial programme theory. However, realist researchers need to identify patterns or demi-regularities that explain the observed outcomes. This synthesis aims at obtaining conjectured ICAMO configurations. The Kaplan-Meier descriptions (quantitative analysis) allowed us to describe the outcome of retention in care and adherence behaviours. While through the qualitative arm of the study, we identified relevant context elements, important mechanisms and emergent outcomes as they relate to the intervention and actors were identified.
The aim of the study was to test an initial programme theory of the adherence club in a real implementation condition. We sought to confirm, refute and/or modify the initial programme theory of the adherence club intervention by applying a case-study approach and collecting data through multi-methods. Following the process of eliciting the initial programme theory, we identified two possible programme theories (Box 1), each offering a different possible explanation of how, why and in what circumstance the adherence club works.
Several steps were taken to ensure the rigour and trustworthiness of the study. Our sampling process used many criteria to ensure that the information gathered is from a credible source. First, the purposive sampling approach allowed us to select only people who would be information-rich informants. This comprised the health-care providers working directly on the adherence club programme and the patients who were receiving care in the programme.
The description of the study context is predominantly from the point of views of the health system and health care providers with little inclusion of the patients’ points of view. This misrepresentation constitutes a limitation as it could introduce potential bias. Although we adopted the purposive sampling approach for the qualitative arm of the study, sampling based on who will provide the best information based on pre-existing assumptions is tricky. For this reason, we purposively sampled the participants based on how long they have been part of the adherence club programme. These characteristics are displayed in Table 2.
In this study, we applied the realist evaluation approach to testing the programme theory of the adherence club intervention. Based on the findings of this study, we have made modifications to the initial programme theory, a first step towards refining the initial programme theory of the intervention. Nevertheless, contributions from other case studies are required to provide further confirmations, refutations and modifications of the initial programme theory to obtain a valuable middle range theory. An empirically refined theory has the potential to inform the adaptive programming and implementation of the adherence club intervention in other areas to improve population-level adherence to ART.