Practicability and effectiveness of the unassisted HIV self-testing compared to the directly assisted HIV self-testing in  the Democratic Republic of the Congo:  A Randomized Implementation Trial


 Background. HIV self-testing (HIVST) may be use free or assisted by health care workers. The aim of this trial was to assess the practicability and effectiveness of unassisted HIVST (UH) versus directly assisted HIVST (DAH) in field settings in the Democratic Republic of the Congo (DRC). Methods. A non-inferiority evaluation using a blood-based HIV self-test was conducted in Kisangani, DRC. Participants were randomized in a 1:1 ratio to UH or DAH. Practicability was defined as the successful performance and the correct interpretation of the result. The linkage to care and the willingness to buy self-test constituted the outcome for HIVST effectiveness. Results. The rate of successful performance of the test was same (93.2%) in UH and DAH. The rate of correct interpretation of the results was 86.9% in UH versus 93.2% in DAH yielding the difference of -6.3% (95% CI: -10.8 to 2.5). UH significantly decreased the rate of correct interpretation of results as compared to DAH (aRR: 0.60 [95% CI: 0.36 to 0.98]; P=0.019). None significant difference was found between two arms in evaluating the linkage to care. Willingness to buy HIV self-test was higher in UH as compared to DAH (92.3% versus 74.1%; aRR: 4.20 [95% CI: 2.42 to 7.32]; P<0.001). Conclusion. This study demonstrates that both UH and DAH show high level of practicability and effectiveness for HIVST. However, additional support tools will be need to improve the practicability of the test in UH. Taken together, UH as well as DAH should improve access to HIV testing in DRC. Trial registration: PACTR201904546865585. Registered 03 April 2019 - Retrospectively registered, https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=6032

trained providers, peer educators or community health workers giving an individual an in-person demonstration before or during HIVST on how to perform the test and interpret the test result. This approach can be used to support self-testers with disabilities, low literacy levels, and individuals who may require or request direct assistance in the form of in-person demonstrations and explanations before, during and/or after testing. On the other hand, the unassisted HIVST (UH) refers to when an individual self-tests for HIV and uses an HIVST kit with instructions for use provided by the manufacturer without the help of a trained provider or peer [6].
The individuals' ability to use HIV self-tests and to interpret the results correctly remains under debated [7][8][9][10][11][12][13][14]. Several studies in sub-Saharan Africa assessing the practicability of the DAH [4,15], the UH [8,10,16,17], and the both together [18] showed that the difficulties in interpreting the selftest results was the main barrier to achieving the performance of the self-test [9]. The errors in interpreting of the self-test can be controlled in DAH, in the other hand the gap will persist in UH due to lack of sufficient support tools [8,9]. Consequently, all misinterpreted self-test could have implications for the risk of spreading HIV especially when a positive test is read as negative [19]. To our knowledge, few field studies have sought to compare the practicability of the HIVST with the unassisted versus directly assisted approach. While it is equally important to orient, on the basis of scientific evidence, HIV programs in a programmatic implementation of the HIV self-testing.
In the Democratic Republic of Congo (DRC), where 46% of people living with HIV do not know their HIV status [20], the policy support HIVST is under development [21]. Although some field evidence on the practicability and performance of DAH has been reported in the general population [8] and key populations such as female sex workers [13] and young adolescents [22], to our knowledge, no study has yet compared UH to DAH in the DRC. This study aims to assess the practicability and effectiveness of UH versus DAH using a randomized, non-blinded, non-inferiority trial among high-risk population for HIV infection acquisition in health facilities in Kisangani, Democratic Republic of the Congo.

Methods
Study design and participants. This randomized implementation trial was conducted between August and November, 2018 in Kisangani, DRC. Trained research assistants (physicians or nurses) enrolled participants at four facilities (University hospital of Kisangani, General Hospital of Kabondo, and the health centers of Neema and Saint Joseph). Participants were eligible for the study if they were between 18 and 49 years, at high risk for acquiring HIV infection, unknowing their HIV status, lived or worked in Kisangani for at least 6 months prior to enrolment, and available and accessible by phone. High risk for HIV infection acquisition was defined as sexually active participants with: a history of unprotected intercourse with one or more partners of unknown HIV sero-status within the past 6 months, new sex partners in the past 6 months, symptoms of sexually transmitted infections (STIs) in the same period, commercial sex activity, or being in a known HIV discordant partnership [18].

Randomization procedures.
Participants were randomized to a ratio of 1:1 through block randomization (block size 4,6,8). Eligible participants were randomly assigned to one of two selftesting groups ( Fig. 1): DAH or UH by using a sealed randomization envelope sequentially. Because of the nature of intervention, study participants and study staff could not be blinded. However, study staff and participant were unaware of the assignment until the envelope is opened.
Study procedures and data collection. The blood-based HIVST was done using the Exacto ® Test HIV (Biosynex, Strasbourg, France) self-test kit which included A3 format color printed pictorial simplified instructions for use in French, Lingala, and Swahili, as previously reported [8]. After obtaining written informed consent and before randomization, participants were administered a baseline questionnaire that measured their demographic characteristics, sexual behaviour, and HIV testing history using self-administrated questionnaire, then they received adequate pre-test HIV counselling.
In the DAH arm, a brief, 10-min face-to-face demonstration of how to use the self-test familiarized participants with the contents of the self-test kit. After this, participant were asked to perform the HIV self-test in a confidential room supervised by trained research assistants (supervisors). Once the test was completed and the participant had recorded the practicability report on a standardized sheet.
The supervisor-interpreted results and the appeals for oral assistance were recorded by supervisor on a standardized sheet. Not that, the supervisors had received rigorous training, including how to talk to participants asking for any support concerning the HIVST.
In the UH arm, participants were asked to perform the HIV self-test at home or in a convenient private location, and read the results guided by the instructions for use without 10-min demonstration and supervision. Participant received training to self-record within 10 minutes after performing the selftest the practicability report on a standardised sheet. Furthermore, participant was invited to return with test cassette and the standardised sheet (putted in a sealed envelope) to the facility within 12-72 h for rereading of test results and additional evaluation. Telephone assistance was offered to the participant if needed. The need for assistance from a trusted person was self-declared by the participant, and recorded by investigators.
In each study arm, confirmatory HIV test using national algorithm rapid tests [21,22] was performed after HIVST if the test was reactive. If seropositivity was confirmed, participants were referred to the care services. Post-test counselling were provided to participant if needed. The standardised sheet included the information on the confirmation of blood presence in the square well of the test, appearance of a control strip on the self-test, and the overall interpreted self-test result. The overall results were recorded as one of three outcomes: (i) may have HIV (preliminary positive); (ii) don't have HIV (preliminary negative); and (iii) test not working (invalid). There was a 24-hour helpline for participants in which the anonymity was assured by recommending participants to introduce themselves using their three-character randomization code. The investigator recorded all information about the telephone assistance on a follow-up sheet.
An exit questionnaire was self-administered after all testing process. It concerned the satisfaction questionnaire, the willing to by HIV self-test kit and the unit purchase price of the test in United State dollar (USD). Study Outcomes. The primary outcomes was the difference in practicability of the Exacto ® Test HIV (Biosynex) self-test kit, comparing the UH versus DAH. Practicability was defined as the successful performance of HIV self-test and the correct interpretation of the HIV self-test result. The successful performance of the HIV self-test was conditioned by the presence of the control strip. Secondary outcomes included the proportions of participants who requested for assistance, the retention rate, the linkage to care, and willing to buy HIV self-test kit if locally available. Retention rate was defined as the number of included participant who completed all evaluation process through the follow-up period. We determined the above secondary outcomes as our measures of implementation effectiveness of HIVST comparing UH to DAH in field conditions of the DRC.
Sample size. A one-sided design to test non-inferiority between groups was used, specifically to test the hypothesis that the practicability of UH is objectively non-inferior to that of DAH. The sample size was estimated using the following formula: with πN and πR the percent of practicability's success of UH and DAH, respectively; with α = 0.05 for a 95% confidence interval; and b = 0.2 for a power of 80%; with the non-inferiority limit (ΔL) corresponding to the greatest loss of effectiveness that is possible to consent [23]. The non-inferiority limit was conventionally set at −10 %, guided by previous studies [8,13,22]. We assumed that πN=98% and πR=88%. The sample size (n=456) was increased by 10% of lost to follow up, giving a final sample size of 530.
Statistical analysis. Primary analysis involved descriptive statistics using mean (standard deviation) or median (interquartile range) for normally distributed or skewed distribution, respectively, then a comparison of outcome measures in study arms was computed by using Pearson's chi-squared test for categorical data or Student t test for means. For the analysis of the primary study outcome, we compared the successful performance of HIV self-test and the correct interpretation of HIV self-test results within individuals between the two arms. For the analysis of the secondary study outcome, we compared the requested for assistance, retention rate, linkage to care, and willing to buy HIV self-test kit if locally available between the two arms. A one sided Wald asymptotic test was used to assess for non-inferiority. The confidence interval for the difference was based on the Wald asymptotic method, at an alpha level of 0.05 corresponding to 95 % confidence limits. Non-inferiority was defined as a lower limit > -10 of the 95% CI around the difference in outcomes. Percent agreement and Cohen's κ coefficient were used to estimate agreement between the participant-interpreted results and investigator-interpreted results.
The satisfactions were assessed using arbitrary quantitative Likert scale based on four different scale ranging from 1 (most difficult), 2 (difficult), 3 (easy) to 4 (very easy). The mean and standard deviation for Likert scale data were calculated and compared between the two arms, using Student t test.
In order to determine the effects of interventions (UH versus DAH) on primary and secondary outcomes, risk ratios from regression of Poisson were evaluated, using two-sided statistical tests with significance level set at P < 0.05. Note that, participants who were not successfully followed up were not included in the analyses as it was not possible to determine the primary and secondary outcomes for them. All analyses were done with SPSS 20.0 (SPSS Inc, Chicago, IL). (89.4%) in the UH arm. Note that, 28 persons were lost to follow up in the UH arm and 2 participants withdrew from study in DAH arm (Fig. 1).
Participants in the two study groups had largely similar characteristics at baseline (Table 1). In brief, participants were predominantly female, aged 25 to 49 years, currently single. Majority was student and had university education level. All participants had evidence of high risk behaviours. Indeed, more than four-fifth participants had unprotected intercourse with one or more partners in the past six months. Nearly half of the participants had tested for HIV in the past, but majority had no knowledge about HIVST before this survey.

Discussion
Our study reports on a trial using blood-based and facility-based HIVST conducted in Kisangani, DRC to evaluate the practicability and effectiveness of UH versus DAH using a randomized, non-blinded, non-inferiority trial among high-risk population for HIV infection acquisition. This study demonstrates in the cultural context of Kisangani that both UH and DAH showed high the rate of successful performance of HIV self-test and correct interpretation of HIVST results. Taken together, this study indicate that UH significantly decreased the rate of correct interpretation of results as compared to DAH. Additionally, our findings show that UH as well as DAH were effective in scaling up HIV testing and linking seropositive person to care even if the will to buy an HIV test was significantly elevated in the UH arm.
In DRC, the progress toward achieving the first 90 target is slower. Thus, a major shift will be needed in the approach to testing to improve effectiveness and efficiency in finding those with an undiagnosed HIV infection [24]. This study is a great opportunity to shed light on both approaches for HIVST distribution in understanding their practicability and effectiveness. Although the rate of successful performance of HIV self-test were high in each arm in our series, the error rate was not also different in UH versus DAH contrary to what Asiimwe and colleagues had found in Uganda where high error rate was observed when participants performed the oral test in UH [18]. Furthermore, greater attention to training before testing may be needed to optimize the use of the HIV self-test in DAH approach [9,16,18].
Although previous studies found no difference in interpretation between self-testers and health-care workers, our findings showed that the concordance in interpretation was substantial between selftesters and health-care workers in DAH with Cohen's k coefficients of 0.69 whereas it was moderate in UH with Cohen's k coefficients of 0.44. Difficulties in interpreting the results have frequently been reported in the literature with difference according the used approach [8,9,13,22]. Given that the misinterpretation of the positive results could have negative consequences in the control of the HIV epidemic [19], and that HIVST is considered a test for triage [6,24], a recent systematic review showed that the positive results were frequently misinterpreted as invalid (2.7 to 6.7%) in studies using the DAH, whereas in those using the UH, the reactive results were often misinterpreted as nonreactive (0.01 to 4.8%) [9]. Nevertheless, our findings show the opposite with 25% of positive results which were misinterpreted as negative in DAH arm and 16.7% of positive results which were misinterpreted as invalid in UH arm. As previously demonstrated, the low educational level could be another explanatory variable beyond interventions (UH and DAH) [8,11,13] because in our series, the proportion of participants with no formal education or primary school was not negligible.
The impact of HIVST in the continuum of care is still poorly documented in sub-Saharan Africa. A field study in Zambia demonstrated a high rate (90%) of linkage to care after HIVST. In our series, noninferiority of UH concerning the retention rate was not shown. Asiimwe and colleagues observed in Uganda that 5 % of participants in the unsupervised self-test arm did not return to report the test result or complete the exit interview [18]. Because of the confidential manner in which self-tests were performed in UH arm, the study team were not able to tract lost individuals to follow-up. Further counselling may be needed to motivate individuals who self-test in UH approach to return to the facility for confirmatory tests, post-counselling and care. However, in our series, most participants who tested HIV seropositive were linked to care in UH arm without difference between UH and DAH, thereby indicating the potential value of UH as way to test and treat person with HIV. However, the monitoring and evaluation of UH remains a real challenge [25]. The cost of an HIV self-test kit has been identified as a potential barrier to adoption, willingness to use, purchase, and the uptake of HIVST, particularly among people in poor-resource settings as Congolese [26][27][28]. In our series, willingness to buy HIV self-test kit was higher in UH arm than in DAH arm (91.6% versus 74.1%). This is supported by a systematic review by Figueroa and colleagues reporting that participants were more willing to pay for unsupervised HIVST than for supervised HIVST, which authors hypothesize to be due to the perception that supervised HIVST is similar to clinic-based voluntary counselling and testing, which is often subsidized in public health care settings [9]. Mokgatle and Madiba showed that the willingness of student in South Africa to purchase a selftest kit was 74.7% without differentiating that this concerned UH or DAH [29]. Assuming that stated willingness to pay in a health research survey likely overestimates actual HIVST purchasing behaviours, market uptake of HIVST is almost certain to be far from optimal. Public funding for HIVST programs would likely improve uptake, and a relevant future research topic is to explore the optimal combination of service provision and subsidy to maximize HIVST uptake among key populations with low or suboptimal levels of recent HIV testing [25].

Strengths and limitations.
The strengths of this survey lie in the randomization, which reduced potential confounding factors between study arms. To our knowledge, this is the first trial in a French speaking country of Africa assessing the practicability and effectiveness of UH versus DAH. Among the limitations of this study, re-reading by the research team of self-test device brought back by participants in sealed envelopes could lead to an error in test interpretation because other studies using the oral fluid-based self-test have shown that delayed re-reading of used oral self-tests is not currently a valid methodological approach to quality assurance and monitoring and may overestimate

Conclusion
In conclusion, our study showed that UH is practicable and effective as DAH among individuals at high risk for HIV infection in Kisangani, DRC. Even if errors in reading the self-test's results and gaps in monitoring are observed in UH group, additional support tools such as the instructional videos, the 24-hour helpline contact, the internet based applications, and the standard counselling prior to UH will need to be explored to improve the practicability and linkage to care. Taken together, UH as well as DAH should improve access to HIV testing in DRC.

Consent for publication. Not applicable
Availability of data and materials. All data generated or analysed during this study are included in this published article and its supplementary information files.
Competing interests. The authors declare that they have no competing interests.  a Difference assessed with Wald asymptotic test; b Non-inferiority was defined as a lower limit > -10 of the 95% CI around the difference in outcomes; * The scale of response of satisfaction questionnaire was assessed by a Likert scale ranging from 1 (most diffic 4 (very easy); the results are mean ± 1 standard deviation (SD); £ Statistical comparisons were assessed by Student t test for the comparisons of means. Figure 1 Flow charts showing enrolment, randomization and follow-up of study participants.

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