Introduction
Timely HIV diagnosis and linkage to care are essential for improved HIV outcomes [
1] but are generally not achieved across sub-Saharan Africa (SSA) [
2,
3]. Haber et al. showed that in Kwazulu-Natal, the transition from receiving an HIV-positive diagnosis to care is the weakest in the HIV care continuum [
4]. A systematic review reported that, among HIV diagnosed individuals, only one-third of ART-eligible patients were receiving treatment [
5]. Cost-effective HIV counselling and testing (HCT) strategies are needed to link more people living with HIV (PLHIV) to care. Few cost-effectiveness analyses (CEAs) on HCT strategies examining linkage to care as an outcome have been conducted, although existing reports have indicated that facility-based strategies are likely more cost-effective than community-based strategies [
6,
7].
In Mozambique, where the adult HIV prevalence is among the highest in the world, only 61% PLHIV know their HIV status, and 54% are receiving ART [
8]. At the time of this study, Mozambique did not have universal HIV testing [
9]. In the country, community-based strategies such as home-based testing (HBT) are infrequently offered [
10]. Voluntary counselling and testing (VCT), initiated by the patient at the health facility, has been a mainstay for HCT while provider-initiated counselling and testing (PICT) is the standard approach for healthcare services [
9]. In Mozambique as well as in other settings with high burden HIV, PICT lacks optimization strategies in order to reach its full potential [
11]. A recent cohort study conducted in Manhiça District found that VCT was associated with the greatest proportion of PLHIV linked to care, followed by PICT and HBT [
12]. Importantly, the study procedures did not influence the linkage-to-care beyond the HCT and facility-based referral.
Economic evidence in relation to costs and cost-effectiveness of these HCT strategies in linking PLHIV to care is lacking. By drawing on prospective data from the Manhiça cohort study [
12], we estimate the costs of providing HCT strategies in Mozambique and examine the cost-effectiveness of PICT and HBT compared to VCT for initiating linkage to care. In doing so, we compared the level of engagement each HCT strategy entails against the outcome.
In the literature, unit costs of HCT strategies from the provider’s perspective are derived from program costs and usually reported as average cost per person tested and/or average cost per HIV-positive individual identified. The former is more relevant for our study and shall be examined in detail for VCT, PICT, and HBT. Estimates of unit costs per person tested vary. For example, VCT costs in Kenya, Swaziland, Tanzania, and Uganda were reported to be US$8.27–US$28.93 [
13‐
17], and PICT costs were lower (US$5.71–US$11.68) [
13‐
15]. In Kenya, South Africa, and Uganda, several studies reported HBT costs ranging from US$5.00 to US$29.00 per client tested, similar to the range reported for VCT [
14,
15,
18‐
20]. Importantly, costs are not directly comparable across studies because the underlying assumptions and contexts may differ. Findings from our study can help inform policymakers on effective yet affordable national-level HCT that could help identify more PLHIV and link them to care in Mozambique.
Discussion
To our knowledge, this is the first study in Mozambique to estimate costs and cost-effectiveness of VCT, PICT, and HBT. We found the median cost per VCT attendance to be as low as US$1.00, largely comprising implicit costs. This is commensurate with VCT prices and patients’ willingness-to-pay reported elsewhere [
34,
35], suggesting that the costs to patients were reasonable. However, differences in health systems, wage structure, and socioeconomic conditions between countries may lead to different valuations of explicit and implicit costs.
We found the average cost to the provider per individual tested and derived costs per HIV-positive patient linked to care to be greatest for HBT, followed by VCT and PICT. Both the magnitude and trend of costs elicited were mostly consistent with the available literature for neighboring SSA countries (in 2009 prices), with the exception of the study by Menzies et al. (in 2007 prices) [
13‐
15]. Notwithstanding considerations for effectiveness, PICT is the cheapest for potential HCT scale-up in areas with inadequate coverage. However, in resource-limited Mozambique, HCT scale-up requires more than mere consideration of HCT costs as improvement of existing healthcare infrastructure and expansion of the healthcare workforce are also needed.
We found HBT to be substantially more expensive than VCT and PICT. This was not consistent with the available literature. Five studies across Uganda, Kenya, and South Africa reported HBT costs ranging from US$5.00–US$29.00 per client tested that were in several cases lower than reported VCT and PICT costs [
14,
15,
18‐
20]. A difference in cost analysis approach likely accounts for this discrepancy, since reported cost estimates from a program perspective are more likely to capture economies of scale accurately, particularly for HBT. Another reason could be the numerous far-lying residential areas in Manhiça [
21], which probably required substantial resources for HBT.
CEA results suggested PICT was not cost-effective to link PLHIV to care, relative to VCT; more precisely, PICT was less expensive but also less effective than VCT. However, this result was only marginal. Moreover, the lack of robustness in the base-case results of the CEA comparing PICT and VCT, coupled with the fact that PICT was consistently reported to be cheaper than VCT [
13,
15] yet with almost comparable linkage-to-care proportions [
6,
36], suggests a high possibility that PICT could be considered cost-effective as well, especially in areas with limited resources. PICT could be considered for expansion and scale-up, depending on the context and available resources, in line with regional trends [
37‐
40]. For example, in remote areas where health facilities may be understaffed, PICT could be expanded to include the general population to lower costs of HCT but still yield reasonable linkage-to-care proportions. Conversely, in areas with more resources and likely higher WTA, PICT could be limited.
As expected, HBT was more expensive and had a lower expected linkage-to-care proportion than VCT. This was consistent with several studies [
19,
41‐
46]. However, other reports showed high linkage-to-care proportions for HBT (47.5%–70.0%) [
47‐
51]. Although definitions of linkage to care were inconsistent in the literature, Kiene et al. highlighted an obvious but important trend: HBT programs that facilitate linkage perform better than those that do not [
52]. Sharma et al.’s systematic review of 126 studies confirmed this trend, showing high linkages to care for strategies that facilitated linkages [
6]. Similarly, Gilbert et al. found community-based TB and HIV integrated screening and linkcage to care strategies to be cost-effective in South Africa [
53]. Moreover, the Manhiça cohort study investigators also hypothesized that strategies to facilitate linkage to care were important for cost-effectiveness [
12]. HBT could be cost-effective if integrated with facilitated linkage strategies.
Our study had limitations. Because data were only available for PLHIV, we modelled total program costs. The inability to determine real program costs may limit the usefulness of our findings for policymakers [
54]. Moreover, the lack of methodological consistency between our study and published studies may result in overestimates and bias cost comparisons. In Mozambique, some HIV-testing costs are borne by the government and others by international donors; our study did not distinguish between the two. In addition, analysis of costs to the provider did not include other costs, such as training, supply chain, and program management. HBT, as analyzed in this study, referred to door-to-door universal testing, and results cannot be extrapolated to other forms of community testing, such as index case testing, which is prominent in SSA testing programs.
Results from this study are hardly generalizable to other countries. Manhiça is a small, semi-rural district in Mozambique where HCT services are offered free-of-charge at district hospitals. It is unclear how the imposition of charges, like in Kenya and Tanzania [
34,
35], would influence HCT uptake and linkage-to-care. The representativeness and precision of this study’s findings may also be limited since only data from a single cohort study were used, and findings are subject to limitations in that study. For example, López-Varela et al. acknowledged that attrition in linkage to care in the cohort study could have been overestimated due to poor record keeping. However, such overestimation is likely lower than in other studies because the authors used data from the Health and Disease Surveillance System [
12].
Because our dataset lacked detailed cost information, we were unable to evaluate the combination of VCT with either PICT or HBT against standalone VCT. Future studies, however, could investigate such combinations and provide information to policymakers on how best to improve existing HIV-testing policies in Mozambique.
A CEA may be unsuitable for assessing the utility of HBT to meet targets for HIV eradication. CEAs are often designed to maximize efficiency at the expense of achieving distributive equality and equity [
55]. Therefore, active HCT approaches, such as HBT, are seldom favored over more passive strategies due to their high unit costs per outcome achieved. Nevertheless, such strategies play a crucial role in achieving HIV eradication. HBT might not be cost-effective but may be equitable because HBT can reach populations distinct from those reached by facility-based strategies [
12]. CEAs can address health equity concerns either through an equity impact analysis or an equity trade-off analysis as introduced by Cookson et al. [
56] Round et al.’s analytical framework, which uses equity weights in decision analyses, may be useful [
57]. Addressing equity is relevant for HCT strategies because factors like age, sex, and socioeconomic status may result in differential rates of uptake and linkage to care [
12,
58,
59].
Despite these limitations, this study generates, for the first time, information for HIV healthcare policy decision making in Southern Mozambique, a setting characterized by one of the highest community based HIV prevalences in the world (i.e., 40%). From the research perspective, this project calls for the need to test the cost-effectiveness of comprehensive home-based strategies including not only screening but also linkage to care and promotion of ART adherence. A similar combination prevention approach involving universal HIV testing and treatment has recently been assessed to be a cost-effective strategy at thresholds greater than US$800 per DALY averted in Zambia and South Africa [
60]. This may be seen as a reasonable threshold also for Mozambique, considering the traditional threshold of three times the gross domestic product (GDP) per capita and that the GDP per capita of Mozambique is just below US$500. However, site specific studies should be carried out to obtain valuable information.
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