RESUMO
As antiretroviral treatment (ART) coverage for people living with HIV (PLHIV) increases, HIV programmes require up-to-date information about evolving HIV risk behaviour and transmission risk, including those with low-level viremia (LLV; >50 to ≤1000 copies/mL), to guide prevention priorities. We aimed to assess differences in sexual risk behaviours, distribution of viral load (VL) and proportion of transmission across PLHIV subgroups. We analysed data from Population-based HIV Impact Assessment surveys in 14 sub-Saharan African countries during 2015-2019. We estimated adjusted prevalence ratios (aPR) of self-reported HIV high-risk behaviour (multiple partners and condomless sex) across cascade stages via generalised estimation equations. We modelled the proportions of transmission from each subgroup using relative self-reported sexual risk, a Hill function for transmission rate by VL, and proportions within cascade stages from surveys and UNAIDS country estimates for 2010-2020. Compared to PLHIV with undetectable VL (≤50 copies/mL), undiagnosed PLHIV (aPR women: 1.28 [95% CI: 1.08-1.52]; men: 1.61 [1.33-1.95]) and men diagnosed but untreated (2.06 [1.52-2.78]) were more likely to self-report high-risk sex. High-risk behaviour was not significantly associated with LLV. Mean VL was similar among undiagnosed, diagnosed but untreated, and on ART but non-suppressed sub-groups. Across surveys, undiagnosed and diagnosed but untreated contributed most to transmission (40-91% and 1-41%, respectively), with less than 1% from those with LLV. Between 2010 and 2020, the proportion of transmission from individuals on ART but non-suppressed increased. In settings with high ART coverage, effective HIV testing, ART linkage, and retention remain priorities to reduce HIV transmission. Persons with LLV are an increasing share of PLHIV but their contribution to HIV transmission was small. Improving suppression among PLHIV on ART with VL ≥1000 copies/mL will become increasingly important.
RESUMO
BACKGROUND: High response rates in surveys are critical to ensuring that findings are unbiased and representative of the target population. Questionnaire length affects response rates, with long interviews associated with partially complete surveys, higher item nonresponse ("don't know" and "refuse" responses), and willingness to participate in future surveys. Our aim is to determine the impact of questionnaire length on blood test participation in population-based HIV surveys. METHODS: Data are from population-based HIV impact assessments conducted in Zambia, Eswatini, and Lesotho in 2016-2017. The population-based HIV impact assessments consist of an interview followed by a blood draw. Consent for blood draw was obtained before the interview in Eswatini and after the interview in Zambia and Lesotho. Interview length was measured by the survey tablet as the time to complete the survey (interview duration) and the number of questions answered by the participant (questionnaire length). We assessed the effects of questionnaire length and interview duration on blood test participation using logistic regression. RESULTS: Across all 3 surveys, the median interview duration was 16 minutes and the median number of questions was 77. In adjusted analyses, there was a negative impact of interview duration on blood draw consent for individuals with unknown status in Lesotho and a positive relationship between questionnaire length and blood draw consent in Zambia for those with HIV-negative and unknown status. CONCLUSION: Although interview length is an important consideration to reduce respondent burden, a longer questionnaire does not necessarily result in lower consent rates for blood testing.