Background
Tuberculosis (TB) and HIV co-infection remain a major global public health problem, particularly in low-and-middle income countries (LMICs) [
1]. A total of 1.5 million people died from TB in 2020 and10 million fell ill, with the largest number of new cases occurring in South-East Asia and Africa, respectively [
2]. HIV/AIDS has significantly fuelled TB incidence as evidence shows that people living with HIV (PLWHIV) have 18 times higher likelihood of developing TB disease compared to those who are HIV negative [
3]. TB is the most common opportunistic infection and the major cause of deaths in PLWHIV [
1]. In 2020, about 215 000 people died of HIV-associated TB [
3].
The World Health Organisation (WHO) recommends the use of isoniazid preventive therapy (IPT) as a global public health strategy to reduce TB incidences among PLWHIV [
4]. IPT is an evidence-based intervention that entails provision of isoniazid, one of the most effective bactericidal, anti-TB drugs, for a duration of 6–12 months [
5]. According to the WHO, IPT reduces the risk of TB by more than 32% among PLWHIV [
6]. Although antiretroviral therapy (ART) is a significant intervention to treat TB in PLWHIV, HIV positive patients receiving ART remain susceptible to active TB disease [
7]. Besides early ART initiation, IPT is a key intervention to prevent TB among PLWHIV [
8]. Many countries where TB and HIV are co-endemic have scaled up delivery of IPT to PLWHIV [
1].
Despite the effectiveness of IPT in preventing progression of latent TB infection into active TB disease, the delivery and uptake of IPT among PLWHIV has remained sub-optimal in most countries [
9,
10]. For example, in the African region, South Africa had majority of newly diagnosed PLWHIV put on IPT in 2019 at 69% and Eswatini had the lowest at about 1% [
2]. Further, in Ethiopia and Zambia, IPT implementation has faced several challenges including poor patient adherence, fear of side effects, development of isoniazid resistant TB, and lack of commitment by health managers to scale up the program [
11,
12].
In Tanzania, an estimated 1.7 million people were living with HIV in 2019 [
13]. Of these, 40,000 contracted TB and 40% died [
14]. The incidence rate of TB among PLWHIV in Tanzania is as high as 16.7 cases per 1000 person-years [
15]. However, only about 59% of PLWHIV eligible for IPT have been put on treatment which is lower than the WHO 90% target [
14].
Tanzania adopted IPT in 2010 and scaled it up across the health system in 2011 [
16]. Although there has been progress in delivering IPT to PLWHIV in Tanzania, challenges remain. For example, only about 58% six-month IPT completion was reported among PLWHIV attending care and treatment in Dar es Salaam between 2013 and 2017 [
17]. Further, a retrospective cohort study found IPT initiation of 14.38% between 2012 and 2016 which is too low to achieve the global treatment targets [
18].
There are various studies that have looked at factors affecting implementation of IPT in other countries [
12,
19,
20]. However, in Tanzania, studies have primarily focused on determining the effectiveness of IPT, completion rate of IPT regimen and knowledge on IPT [
21‐
23]. There has been limited assessment of the contextual factors that shape delivery and uptake of the IPT intervention. This study aimed to bridge this gap through assessing contextual factors that shape delivery and uptake of the IPT intervention in Dar es Salaam, Tanzania using the consolidated framework for implementation research so as to inform policy guidelines towards effective implementation of IPT [
24].
Methods
Theoretical framework
We used the consolidated framework for implementation research (CFIR) to assess the context in which IPT is delivered and how it shapes IPT uptake among PLHIV [
25]. The CFIR was developed to guide systematic assessment of multilevel contexts that influence implementation of an intervention. CFIR is a determinant framework consisting five domains that we used to categorise the contextual factors that shape delivery and uptake of IPT [
26]. These domains include the characteristics of the intervention, inner setting, outer setting and individuals involved and process of implementation [
25]. We used the CFIR to guide data collection, data analysis, coding, and interpretation of the findings.
Study design
We used an exploratory qualitative case study design [
27,
28]. The case comprised the IPT program including the delivery systems, related health facilities, health services managers, health providers and PLWHIV in Dar es Salaam region, Tanzania. This design is most appropriate because it allowed us to explore in detail the IPT intervention and its interaction with the contextual factors that shape its delivery and uptake [
28].
Study setting
This study was conducted in Dar es Salaam, a major commercial city and key contributor of new TB cases in Tanzania, with 20% of all TB cases in the country notified from this region in 2017 [
29]. The National HIV impact survey reported a regional HIV prevalence of 4.7% among adults 15 years and older [
30]. Dar es Salaam is the most populous city in Tanzania with a population of about 5.5 million [
31]. In relation to TB/HIV services, in 2018 Dar es Salaam had a total of 123 HIV clinics where IPT is offered [
30].
Study participants
The study participants comprised of 7 health administrators at different levels of IPT implementation from the government and non–governmental organizations, 9 clinicians and 17 people living with HIV. All participants were at least 18 years old. Table
1 shows the different categories of participants who took part in the study.
Table 1
Categories of participants
Key informant interviews |
1 | Health administrators | 7 |
2 | Clinicians (nurses and doctors) | 9 |
Sub total | 16 |
In-depth interviews |
3 | Patients/PLHIV | 17 |
Sub total | 17 |
Total | 33 |
Sampling and recruitment of study participants
The study utilized purposive sampling methods to select participants and achieve a maximum-diversity sample. Health administrators and the providers were selected based on their experience in the delivery of IPT services whilst the PLWHIV were supposed to either be on or had completed the IPT regimen. Those who did not meet these criteria were excluded. The clinics were purposively sampled based on their performance in IPT delivery in consultation with the district health administration. Two clinics were selected from each of the five districts within Dar es Salaam including Kigamboni, Temeke, Ilala, Ubungo and Kinondoni.
The PLWHIV were recruited at the clinics with assistance from the TB/HIV focal person and sister in-charge who worked with the researcher to identify patients who were eligible among those who attended the clinic on the interview day. However, the researcher had the final choice of which patient to be interviewed from among the ones recommended. Two patients were interviewed from each of the clinics. We tried to balance the sex and general representation of various social categories in the way the study participants, particularly PLWHIV were recruited.
Data collection
The data collection comprised of key informant and in-depth interviews. Having obtained permission to collect data from all the districts and selected clinics, patient files were reviewed to confirm the IPT regimen. The interviews were face-to-face except for one done by phone. The interviews were conducted in a private room using an interview guide (Additional file
1) and lasted between 30 and 60 min. The interview guide was developed based on CFIR framework [
25].
Due to the COVID-19 pandemic, a distance of at least 2m between interviewer and the interviewee was observed. Moreover, both the interviewers and the study participants wore protective masks. Each interview was audio recorded and the interviewer took some notes during the sessions. All interviews were conducted by the first author RFN, a postgraduate public health student and Tanzanian male doctor with training in qualitative methods in implementation research at the University of Zambia. Data were collected between January and February 2021.
Although we achieved saturation of data with 25 interviews, we continued to a total of 33 which, however, did not reveal new information (Table
1). The concept of “theoretical saturation,” a point when additional data does not produce new information, is an accepted standard for determining the sample of a qualitative inquiry [
32]. In total, we conducted 16 key informant interviews and 17 in-depth interviews (Table
1).
Data analysis
This study employed thematic analysis, an approach in which themes, patterns and relationships are identified, analyzed and presented from the qualitative data [
33]. Recorded interviews were transcribed verbatim in Swahili language. Thereafter, English version of the transcripts were developed to enable detailed review by a research team. The transcripts were then read several times to develop codes from which themes were synthesized. Codes and themes were developed both deductively using the CFIR and inductively using the context specific emergent issues from the data (Table
2) [
25]. All the team members iteratively discussed the final coding framework and agreed on the relevant structure of presenting the coding reports. Each member manually coded a specific number of transcripts and discussed with the research team to reach consensus on emergent issues.
Table 2
CIFR domains and the emergent themes
Characteristics of intervention | Source of intervention Implementation costs | Proven effectiveness of IPT in preventing active TB Adaptability of IPT to patient schedules IPT provided for free of charge Adverse side effects of IPT Indirect costs incurred by patients IPT pills burden | Facilitator Facilitator Facilitator Barrier Barrier Barrier |
Characteristics of individuals | Knowledge and belief about the intervention | Good knowledge and attitude among clinicians and patients Accepting HIV status and having taken IPT before | Facilitator Facilitator |
Process of implementation | Engaging | Collective planning prior to IPT delivery Key stakeholder engagement Collective evaluation of IPT delivery and uptake | Facilitator Facilitator Enabler |
Inner settings | Organizational culture Implementation climate | Communication among staffs participating in IPT delivery Commitment of institutional leadership Shortage of staff and lack of diagnostics facilities | Facilitator Facilitator Barrier |
Outer settings | Cosmopolitanism Sociocultural | Network of health facilities sharing resources HIV related stigma Some Negative cultural and religious values Poverty and weak health systems | Enabler Barrier Barrier Barrier |
Ethical considerations
This study obtained ethical approval from the University of Zambia Biomedical Research Ethics Committee (UNZABREC) (REF. 1022-2020) to conduct the research. Approval was also provided by the National Institute of Medical research in Dar es Salaam, Tanzania (NIMR) (Ref: NIMR/HQ/R.8a/Vol.IX/3541) where the data was collected. All prerequisite authorisations were obtained from the Tanzania Ministry of Health. We also obtained permission from the regional and district office, and the hospital management before data collection. All participants (> 18 years) provided written, informed consent to participate in the study. If participants were not literate, a witness was required to be present during the consenting process and sign consent on their behalf. The participants gave separate consent to being audio recorded. Confidentiality was assured by maintaining anonymity of participants who were assigned a unique codes to de-identify them during data reporting.
Discussion
Characteristics of IPT such as aligning the therapy to individual patient schedules and its relatively low cost facilitated its delivery and uptake. On the contrary, perceived adverse side effects of IPT negatively affected the delivery and uptake of IPT. Characteristics of individuals delivering the therapy including their knowledge and good attitudes, commitment to meeting set targets facilitated the delivery and uptake of IPT. The process of IPT delivery comprised collective planning and collaboration among various facilities which facilitated its delivery and uptake. Organisational characteristics including communication among units and supportive leadership facilitated the delivery and uptake of IPT. External system factors including HIV stigma, negative cultural and religious values, limited funding as well as shortage of skilled healthcare workers presented as barriers to the delivery and uptake of IPT.
Characteristics of the IPT intervention shaping delivery and uptake
Characteristics of the IPT intervention may act as barriers to its delivery and uptake. For example, the large number of isoniazid pills to be taken, duration, inconsistent availability of the drug and associated side effects such as neuropathy result in patients shying away from the intervention. Similar findings have been reported in studies conducted Kenya and Ethiopia [
9,
11]. These studies also highlight critical health system barriers to the delivery and uptake of IPT such as lack of commitment by health managers to scale up and lack of an integrated monitoring and evaluation systems. On the other hand, good attributes of the IPT intervention such as its adaptability to patient schedules, IPT’s proven effectiveness as well as it being provided free of charge facilitate its delivery and uptake as reported in similar studies [
22,
34‐
36]. However, indirect costs incurred by the PLWHIV to access healthcare pose as a barrier to IPT delivery and uptake.
Characteristics of the individuals involved in delivery and uptake of IPT
Knowledge, beliefs, and attitudes of healthcare providers and PLWHIV towards IPT were found to be key factors shaping its delivery and uptake. The value of PLWHIV having appropriate knowledge is critical to address misunderstandings of IPT’s preventive role in the absence of TB symptoms [
37]. One study found that when PLWHIV share wrong beliefs about IPT at community level its delivery and uptake becomes a challenge [
20]. In addition, acceptance of one’s HIV status and having taken IPT for a long period of time facilitates its delivery and uptake as reported in similar studies [
22,
38]. A possible explanation is that once PLWHIV accept their status and assume responsibility, adherence to treatment comes naturally.
The organisational processes shaping delivery and uptake of IPT
The engagement of PLWHIV as IPT champions facilitated its delivery and uptake. The IPT champions performed various tasks such as daily health talks, linking fellow patients to services, and participating in counselling sessions. Our finding reaffirm what has already been reported in other studies whereby using people from the affected community to deliver an intervention facilitates its uptake [
9,
39]. The use of champions selected among PLWHIV helps to build and sustain trust in not only the IPT intervention, but also the health system in general [
39,
40]. This contributes to ensuring that PLWHIV adhere treatment instructions as prescribed by the responsible healthcare workers. Because of their experience, treatment champions also play an important role in countering and myths that otherwise impede PLWHIV from taking the IPT intervention.
Internal organisational characteristics shaping delivery and uptake of IPT
Leadership support towards the IPT program through ensuring availability of supplies, providing mentorship and supervision facilitated its delivery and uptake. Evidence of the importance of leadership in influencing IPT delivery and uptake has also been documented in several other studies [
11,
19]. These studies have found that the lack of support of the leadership overseeing HIV related care has hindered effective delivery and uptake of IPT services. Leadership support within the organisation provides a critical element for channelling implementation efforts towards IPT program success through providing strategic direction and oversight [
41].
Outer settings influencing delivery and uptake of IPT
Sharing experiences and learning from other clinics implementing the IPT program was found to play a significant role in facilitating its delivery and uptake. Networking among clinics implementing IPT not only facilitates communication but also enables exchange of resources which helps to guarantee continuity of IPT services to PLWHIV. This finding is supported by a similar study from Kenya which reports that a lack of interoperability between clinics hindered delivery of IPT services [
9].
We found that HIV societal stigma hinders the delivery and uptake of IPT services. However in a southern African study HIV related stigma was reported to have no effect on IPT uptake [
37]. A possible explanation to this difference may be because PLWHIV in South Africa were more confident in their ability to navigate stigma by pretending that their medications were for unrelated conditions. On the contrary, PLWHIV in our study seemed to find it a challenge to navigate the HIV/TB co-infection related stigma when it comes to IPT treatment uptake decisions. Furthermore, negative cultural and religious values also hinder delivery and uptake of IPT services as reported in similar studies [
11,
42].
This study had several limitations, firstly the collection of data from an urban area, Dar es Salaam meant that most of the views are likely to represent people of better socioeconomic standing. Secondly the small sample size as well as limited variability within entails that we may not be able to aptly transfer our findings to similar settings. Lastly, we take cognizance of the desirability bias that may occur due to the interviewees wanting to give a positive impression of the IPT program performance in their clinic. However, even with these weaknesses, the research team tried to ensure that quality data were collected. The team comprised of seasoned qualitative researchers with experience in implementation and health systems research. During data analysis, the team ensured that the views were triangulated among the different category of participants to ensure trustworthiness of the findings. Further, the iterative process of analysing the data enhanced the validity of our findings. This study has added knowledge to and reaffirmed what is already known about implementation of IPT which can help health policy makers, clinicians, and patients to improve effectiveness of this intervention.
Acknowledgements
Renatus Fabiano Nyarubamba is a recipient of a TDR scholarship under the postgraduate training scheme in implementation research at the University of Zambia, School of Public Health. I am grateful for the support from the training scheme, as provided by the UNICEF/UNDP/World Bank/WHO special programme for Research and Training in Tropical Diseases (TDR). I wish to extend my gratitude to my supervisors at the Department of Health Policy and Management, School of Public Health, University of Zambia, Dr. Paschal Mdoe of Haydom Lutheran Hospital, Tanzania, NIMR, and all participants of our study.
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