Participation Dynamics in Population-Based Longitudinal HIV Surveillance in Rural South Africa

Larmarange, Joseph; Mossong, Joël; Bärnighausen, Till; Newell, Marie‐Louise

doi:10.1371/journal.pone.0123345

Cited by 41 publications

(49 citation statements)

References 43 publications

(36 reference statements)

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“…Another limitation is that some people eligible for HIV testing in the surveillance cannot be contacted in a specific year or refuse to test for HIV. However, over 5 years, more than 80% of eligible individuals tested for HIV at least once in the study population, 34 ensuring that, during the observation period, most people with HIV were included in our sample. We would expect that people who do not test for HIV have even lower rates of linkage to care and other cascade progressions than those in our study, suggesting that our conclusions are likely to be conservative.…”

Section: Discussionmentioning

confidence: 99%

From HIV infection to therapeutic response: a population-based longitudinal HIV cascade-of-care study in KwaZulu-Natal, South Africa

et al. 2017

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Summary Background Standard approaches to estimation of losses in the HIV cascade of care are typically cross-sectional and do not include the population stages before linkage to clinical care. We used indiviual-level longitudinal cascade data, transition by transition, including population stages, both to identify the health-system losses in the cascade and to show the differences in inference between standard methods and the longitudinal approach. Methods We used non-parametric survival analysis to estimate a longitudinal HIV care cascade for a large population of people with HIV residing in rural KwaZulu-Natal, South Africa. We linked data from a longitudinal population health surveillance (which is maintained by the Africa Health Research Institute) with patient records from the local public-sector HIV treatment programme (contained in an electronic clinical HIV treatment and care database, ARTemis). We followed up all people who had been newly detected as having HIV between Jan 1, 2006, and Dec 31, 2011, across six cascade stages: three population stages (first positive HIV test, HIV status knowledge, and linkage to care) and three clinical stages (eligibility for antiretroviral therapy [ART], initiation of ART, and therapeutic response). We compared our estimates to cross-sectional cascades in the same population. We estimated the cumulative incidence of reaching a particular cascade stage at a specific time with Kaplan-Meier survival analysis. Findings Our population consisted of 5205 individuals with HIV who were followed up for 24 031 person-years. We recorded 598 deaths. 4539 individuals gained knowledge of their positive HIV status, 2818 were linked to care, 2151 became eligible for ART, 1839 began ART, and 1456 had successful responses to therapy. We used Kaplan-Meier survival analysis to adjust for censorship due to the end of data collection, and found that 8 years after testing positive in the population health surveillance, 16% had died. Among living patients, 82% knew their HIV status, 45% were linked to care, 39% were eligible for ART, 35% initiated ART, and 33% had reached therapeutic response. Median times to transition for these cascade stages were 52 months, 52 months, 20 months, 3 months, and 9 months, respectively. Compared with the population stages in the cascade, the transitions across the clinical stages were fast. Over calendar time, rates of linkage to care have decreased and patients presenting for the first time for care were, on average, healthier. Interpretation HIV programmes should focus on linkage to care as the most important bottleneck in the cascade. Cascade estimation should be longitudinal rather than cross-sectional and start with the population stages preceding clinical care. Funding Wellcome Trust, PEPFAR.

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Section: Discussionmentioning

confidence: 99%

From HIV infection to therapeutic response: a population-based longitudinal HIV cascade-of-care study in KwaZulu-Natal, South Africa

et al. 2017

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“…Additionally, only 26–46% of the eligible South African participants contacted provided a blood sample for HIV testing, which may have affected estimates of the associations between ART coverage and incidence. 19 The Mombasa female sex workers study in Kenya reported that each 10% increase in ART coverage among all HIV-infected persons in the region was associated with a 23% reduction of HIV acquisition risk in female sex workers , but such regional coverage may not accurately reflect exposure among the male partners of the sex workers. 20 Neither the South African nor the Mombasa study assessed the associations of MMC coverage with HIV incidence.…”

Section: Discussionmentioning

confidence: 99%

Association of Medical Male Circumcision and Antiretroviral Therapy Scale-up With Community HIV Incidence in Rakai, Uganda

Kong

Kigozi

Ssekasanvu

et al. 2016

JAMA

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“…In the case of the Africa Centre, virtually all eligible households were contacted and agreed to participate in the HIV surveillance. Moreover, almost all eligible residents were successfully contacted to request their participation in testing (e.g., 94.3% in 2009 [5]). Therefore, practically all missing data at the Africa Centre arise through individuals directly refusing to test.…”

Section: Discussionmentioning

confidence: 99%

“…In 2009, only 5.7% of eligible respondents could not be contacted [5]. The high contact rate is likely a result of the HIV survey operations, which include household revisits at later dates, after working hours, and on weekends.…”

Section: Methodsmentioning

confidence: 99%

“…The main reason eligible residents did not participate in HIV testing at the Africa Centre is that they declined consent for an HIV test. In 2009, only 5.7% of eligible respondents could not be contacted [5]. The high contact rate is likely a result of the HIV survey operations, which include household revisits at later dates, after working hours, and on weekends.…”

Section: Setting and Datamentioning

confidence: 99%

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Adjusting HIV prevalence estimates for non‐participation: an application to demographic surveillance

McGovern

Marra

Radice

et al. 2015

Journal of the International AIDS Society

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IntroductionHIV testing is a cornerstone of efforts to combat the HIV epidemic, and testing conducted as part of surveillance provides invaluable data on the spread of infection and the effectiveness of campaigns to reduce the transmission of HIV. However, participation in HIV testing can be low, and if respondents systematically select not to be tested because they know or suspect they are HIV positive (and fear disclosure), standard approaches to deal with missing data will fail to remove selection bias. We implemented Heckman-type selection models, which can be used to adjust for missing data that are not missing at random, and established the extent of selection bias in a population-based HIV survey in an HIV hyperendemic community in rural South Africa.MethodsWe used data from a population-based HIV survey carried out in 2009 in rural KwaZulu-Natal, South Africa. In this survey, 5565 women (35%) and 2567 men (27%) provided blood for an HIV test. We accounted for missing data using interviewer identity as a selection variable which predicted consent to HIV testing but was unlikely to be independently associated with HIV status. Our approach involved using this selection variable to examine the HIV status of residents who would ordinarily refuse to test, except that they were allocated a persuasive interviewer. Our copula model allows for flexibility when modelling the dependence structure between HIV survey participation and HIV status.ResultsFor women, our selection model generated an HIV prevalence estimate of 33% (95% CI 27–40) for all people eligible to consent to HIV testing in the survey. This estimate is higher than the estimate of 24% generated when only information from respondents who participated in testing is used in the analysis, and the estimate of 27% when imputation analysis is used to predict missing data on HIV status. For men, we found an HIV prevalence of 25% (95% CI 15–35) using the selection model, compared to 16% among those who participated in testing, and 18% estimated with imputation. We provide new confidence intervals that correct for the fact that the relationship between testing and HIV status is unknown and requires estimation.ConclusionsWe confirm the feasibility and value of adopting selection models to account for missing data in population-based HIV surveys and surveillance systems. Elements of survey design, such as interviewer identity, present the opportunity to adopt this approach in routine applications. Where non-participation is high, true confidence intervals are much wider than those generated by standard approaches to dealing with missing data suggest.

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Participation Dynamics in Population-Based Longitudinal HIV Surveillance in Rural South Africa

Cited by 41 publications

References 43 publications

From HIV infection to therapeutic response: a population-based longitudinal HIV cascade-of-care study in KwaZulu-Natal, South Africa

From HIV infection to therapeutic response: a population-based longitudinal HIV cascade-of-care study in KwaZulu-Natal, South Africa

Association of Medical Male Circumcision and Antiretroviral Therapy Scale-up With Community HIV Incidence in Rakai, Uganda

Adjusting HIV prevalence estimates for non‐participation: an application to demographic surveillance

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