This study showed that the incremental cost-effectiveness ratio expressed as the incremental costs per patient with undetectable viral load was US$1419. Going by the cost-effectiveness threshold suggested by Woods et al., 2016 [13], the Incentive Scheme was not cost-effective. The sensitivity analyses showed that adjusting the effectiveness outcome for regimen change to Dolutegravir-based combination, and changes in the cost estimates of the cost drivers by +/− 25% did not yield ICER below the threshold. However, if the CD4 count and viral load test are performed at most triannually, the intervention will become cost-effective. Thus, the ICER obtained in our study showed that the intervention was not cost-effective, but will become cost-effective if the key laboratory health indicators (CD4 count and viral load tests) for HIV patients are performed 1–3 times per annum.
On the feasibility assessment, the healthcare providers reported that patients’ acceptance of the intervention was very high, as evident from the regular attendance of monthly appointments. We gathered that the views of the healthcare providers on the new intervention could be placed into seven major themes: improved adherence, attitude towards the disease, sustainability concerns, healthcare provider-adolescent relationship, caregivers influence, cost implications and intervention implementation challenges.
The findings from the cluster-randomized trial and the view of the healthcare providers suggest that the Incentive Scheme increased the virologic outcomes of adolescents living with HIV. Previous studies on interventions to improve adolescents’ adherence to therapy have shown that monetary rewards influence behaviours [16,17,18]. In a single-centre adherence intervention combining financial incentives (total expenditure £1350) with motivational interviewing for adolescents with perinatally- acquired HIV infection, there was improved virological outcomes [16]. For young people who may not fully comprehend the implication of having to live with the virus, with the consequent lifelong use of medications, low adherence to regimen would be very common. Therefore, to increase adherence rates, it may be necessary to reward them for doing what they ought to be doing anyway. In our trial, the monetary rewards attracted the adolescents to the scheme, while the motivational interviewing provided an avenue for them to connect with the healthcare providers. This connection brought about an intrinsic motivation that would sustain lifelong positive behaviour change. The client-centred counselling style of motivational interviews likely helped the patients move away from a state of indecision and towards motivation to making positive decisions.
The expectation of monetary rewards was an extrinsic motivator. Unfortunately, it is known that cash incentive may not be able to bring about lifelong positive behaviour change. A few post-intervention evaluations found that adherence rates diminish when interventions are withdrawn [17, 18]. Motivational interviewing was found to foster a better relationship between healthcare providers and adolescents. It has also been found effective in influencing health behaviours, improving adherence and changing harmful lifestyle among people with chronic diseases [19]. In an integrative review to examine the use of motivational interviewing to improve health outcomes in persons living with HIV, it was discovered that studies using motivational interviewing either alone or in conjunction with other service delivery interventions, recorded improved adherence, decreased depression, and decreased risky sexual behaviour [20]. The IDI participants also reported a positive relationship between motivational interviewing and treatment adherence. It also improved the adolescents’ understanding of their disease condition.
The interventions hold promising prospects, but doubts have been expressed by the IDI participants about sustainability. Although none of them expressed frustrations about any disruptions in clinic workflow during the intervention implementation emanating from the trial, there were concerns about the increase in workload and financial requirements for the incentives in a real-life setting. Therefore, a team of dedicated healthcare providers would be needed to drive the intervention in a real-life setting. Additional remuneration for the staff involved was also recommended. Healthcare staff providing the motivational interviewing needs to exude confidence in their capacity to conduct it. Thus, the capacity building of healthcare staff on motivational interviewing would enhance the impact of the intervention. The skillset required for successful implementation of motivational interviewing includes but not limited to gaining an understanding of the philosophy behind it, acquisition of basic client-centred counselling skills, as well as recognizing and reinforcing change [21].
Another genuine concern expressed by the health care workers is the financial sustainability of the Incentive Scheme. We believe that the Incentive Scheme can be sustained financially by incorporating it as one of the social welfare schemes that are operational in Nigeria such as the school feeding programme [22] and Tradermoni [23]. The Incentive Scheme could be targeted to assist adolescents who cannot afford transportation fares for hospital appointments or applied to hospitals in rural and poor settings as a way of reducing the cost of implementation. Incentive scheme as social welfare programme will have the dual purpose of improving the health and economic status of the beneficiaries. The healthcare providers indicated that the orphaned adolescents were cared for by guardians who may have limited earning capacity. This places immense financial stress on them as much of their income is spent on household expenses. Also, the interviewees stated that the majority of the HIV adolescents came from poor backgrounds and hence have difficulties affording transportation fares to the hospitals. A lot of HIV adolescents need financial support for self-sustenance especially as some of them have lost at least one parent to HIV/AIDS.
The study had some limitations. One major limitation of the study was the lack of sample size adequacy. Some of the hospitals had a low client load and could not recruit up to the expected sample size (23 adolescents living with HIV). Thus, the trial did not reach the desired sample size. Given that retention in care was one of the trial outcomes, we could not influence retention in the study beyond what is done routinely in the hospitals used for the trial. Another limitation was that the baseline viral suppression in the intervention group was significantly lower than in the control group and more participants in the intervention arm changed to a more efficacious therapy during the 1 year period. Thus, in addition to the Incentive Scheme intervention, these factors could have contributed to a larger change in viral load suppression observed in the intervention arm. Also, since the effectiveness outcome was not measured as QALY, the cost-effectiveness threshold was used approximately to gauge the cost-effectiveness of the intervention. The interview was not all-inclusive as it focused on the healthcare personnel without also exploring the perspectives of the HIV clients who are the direct beneficiaries of the intervention. Therefore, we may have missed some vital information that may enhance or hinder the feasibility of the incentive scheme from the ALHIV. However, the interviewees bared their minds based on their several contacts with the adolescents. Also, the assessment of the effectiveness outcome was on a short-term basis. It was not clear whether the intervention effect could be sustained after intervention withdrawal, in which case the ICER would be lower, translating to a more efficient intervention.
Given the dwindling funding for HIV program, there is a need for careful consideration of any intervention to be included as part of the HIV program. In this study, we have illustrated how cost-effectiveness analysis can be applied to an HIV service delivery intervention to establish its efficiency. Such analysis will better enable public health decision-makers to determine health interventions that will produce the greatest benefits given resource constraint.