In this retrospective cohort study, the HIV VL suppression proportion was 67% following IAC intervention for HIV infected adults at Kiswa Health Centre, who had been on ART for at least six months and had an unsuppressed VL in the period from January 2018 and June 2020. Linkage to IAC following the baseline unsuppressed VL was 100% in the study population. 48.6% of study participants were linked to the IAC intervention in less than a month from the time of the non-suppressed VL result. 95% of study participants received three or more IAC sessions. Majority of participants (46.7%) completed IAC between 13 and 24 weeks and only 34% completed the IAC intervention in the recommended 12 weeks.
A retrospective cohort study in rural Uganda in 2017 found that 19% of 411 PWHIV with an unsuppressed VL did not receive IAC [37] while another earlier retrospective review conducted at 15 Uganda public health centers from June 2015 to December 2016 found that 7% of 449 study participants with VL above 1000 copies/ml did not have any IAC session provided [16]. This improvement in IAC linkage reflects the increased efforts by Ministry of Health in Uganda which is geared towards increased routine HIV VL testing to quickly refer for the IAC intervention all PWHIV identified to have unsuppressed VL [13].
The study results on IAC linkage are comparable to findings from Ethiopia where all 235 PWHIV with unsuppressed VL involved in the retrospective cohort study received IAC [12], and findings from South Africa where all 400 eligible participants received IAC in a prospective cohort study [20]. IAC linkage in our study is 24.3% higher than the findings from a retrospective cohort study in Zimbabwe where out of 646 participants with unsuppressed VL, 75.7% were enrolled into IAC [14].
In this study cohort, 77.4% of study participants received the first IAC session within 60 days or less from the time of the baseline non-suppressed VL result. This is an improvement by approximately 20 weeks in the aptness of IAC intervention provision in a public health facility setting when compared to earlier findings where the first IAC session was received up to 200 days following the unsuppressed VL result availability by 75% of study participants [16]. However, the recommended time to first IAC session is 30 days as per Uganda national guidelines [13]. Enhanced adherence counseling (EAC) is more timely in Ethiopia as 8 weeks is the median time to the first counselling session [12].
Only 34% of participants completed the recommended three IAC sessions in 12 weeks in the study, a proportion 12.8% smaller than the proportion of study participants who completed IAC in the recommended three months in a retrospective cohort study in Ethiopia [12].
75% of study participants had completed the IAC intervention in 20 weeks, which was an improvement by 30 weeks in comparison to the findings of the same percentage (75%) of participants who finished the three IAC sessions after 50 weeks in an earlier retrospective cohort study conducted in Uganda [16].
66.78%, the VL suppression proportion for all participants who received the recommended three or more IAC sessions is 58% more than the VL suppression percentage after IAC documented by a prospective cohort study [29] and 44% higher than the VL suppression proportion documented by a retrospective research [16], which studies were both conducted in public HIV health care settings in Uganda. This VL suppression proportion of 66.78% is comparable to 70%, a percentage above which adherence support has been found to enhance VL suppression in PWHIV with a previously unsuppressed VL [17, 18]. In addition, 66.78% is comparable to: 66.4%, the VL suppression proportion after IAC for Ethiopia [12] and 67.5% [38] as well as 64% [20], the VL suppression proportions after IAC documented for South Africa. The VL suppression proportion of 66.78% found in our study is also comparable to 67%, the VL suppression proportion after IAC for Burkina Faso, Côte d’Ivoire, Senegal and Mali [39]. However, 66.78% is way higher than the VL suppression percentage stated in Zimbabwe following EAC [14] and the VL suppression of 10% found in a prospective cohort study in Tanzania following reinforced adherence counseling [40]. All study participants who achieved viral re-suppression after IAC did not require ART regimen switch which inherently helped in the preservation of the next line ART medications for when their need is warranted; a very core aim of the IAC intervention.
The study findings are contrary to those in a Swaziland study where EAC did not increase the likelihood of VL suppression [41].
Bivariable analysis showed an association between VL suppression after IAC and number of IAC sessions received, baseline non-suppressed VL result and ART regimen. Multivariable modified Poisson regression analysis findings demonstrated significant associations between VL suppression after IAC and number of IAC sessions received, baseline non-suppressed VL result and ART regimen type. The participants who received three IAC sessions were 33% more likely to have VL suppression than those who received more than 3 IAC sessions (4, 5 or 6 sessions), (ARR: 1.33, 95% CI: 1.16–1.53, p < 0.001). On the contrary, number of intensified adherence counseling sessions received was found not to be independently associated with VL suppression in a retrospective cohort study in Zimbabwe [14]. However in this Zimbabwean study, the participants who received three IAC sessions were more likely to virally suppress after IAC (68%) when they were compared to those that did not receive any enhanced adherence counseling session [14].
Study findings support the current Uganda national guidelines that the recommended three IAC sessions are potent and by a larger proportion, in reversing HIV viral non-suppression among PWHIV who have been on ART for at least six months [13], as it is mostly challenges with good adherence to ART that lead to VL non-suppression [10–14].
The study participants whose VL was in the range 1,000–4,999 copies/ml were 47% more likely to suppress after IAC compared to their counterparts with VL ≥ 10,000 copies/ml (ARR: 1.47, 95% CI: 1.26–1.73, p < 0.001). Additionally, the probability of VL suppression was 19% higher for study participants whose VL was between 50,000–10,000 copies/ml in comparison to those whose VL ≥ 10,000 copies/ml (ARR = 1.19, 95% CI: 0.86–1.66). The study results are comparable to findings of a retrospective cohort study in Ethiopia where the baseline VL result was an important predictor of VL suppression after IAC [12]. In Ethiopia, the VL suppression probability was 56% lower for study participants with a VL greater than 10,000 copies/ml; and 7% lower for participants whose VL was between 5001–10,000 copies/ml when both categories were compared to those who had a baseline VL of 1,000–5,000 copies/ml [12]. Baseline VL ≥ 10,000 copies/ml was also associated with increased odds of VL non-suppression after EAC in Ethiopia from a case-control study [42]. Nevertheless, younger age, extended duration on ART, CD4 cell count of 201to 500/mm3 and residing in an urban area are factors found to be positively associated with suppression of VL after EAC in Ethiopia [43]. Similarly, in a retrospective cohort study in Zimbabwe, the participants with a baseline VL greater than 5000 copies/ml had a lower probability of VL suppression after IAC in comparison to those with baseline VL between 1000–5000 copies/ml, with the likelihood of VL suppression reducing with increasing VL test result [14]. The reduced likelihood of viral suppression after the IAC intervention in persons with very high baseline VL results can be linked to possible unidentified accumulated pre-existing resistance to ART and in such individuals, only switching to the next effective ART regimen most accurately determined by resistance testing can reverse the viral non-suppression. Unfortunately, due to cost implications, HIV resistance testing is reserved for limited categories of PWHIV in Uganda including those failing on their second and third line ART regimens [13].
Study strengths and limitations
Study strengths include the cohort design which inherently provided a temporal causal relationship between IAC and VL suppression [44], a large sample size and utilization of routine patient information collected in a public HIV clinic in an urban setting, thus making the sample representative of the HIV clinic and generalizable to other urban HIV clinics in Kampala and Wakiso districts in Uganda. The major study limitation was utilization of routine clinic data which had missing information and therefore data analysis and interpretation was limited to routinely collected and documented variables in the client records. Important patient variables which could have affected the baseline and repeat VL testing, linkage to IAC and viral suppression post IAC like socio-economic status, education level and distance of patients’ residence to the HIV clinic were unavailable. Lastly, since it was an entirely quantitative study, health workers and participants experiences and perceptions regarding the IAC intervention and its delivery were not studied, which could have been examined by qualitative methods.