Reliability of reporting of HIV status and antiretroviral therapy usage during verbal autopsies: a large prospective study in rural Malawi

Assessing the validity of and factors that influence accurate self-reporting of HIV status after testing: a population-based study

OBJECTIVES

To assess the validity of self-reported HIV status, and investigate factors that influence accurate reporting of HIV-positive status, in a population tested and informed of their HIV test result.

DESIGN

Prospective cohort study.

METHODS

We compared self-reported HIV status with biomarker-confirmed HIV test status among participants of Karonga Health and Demographic Surveillance Site in rural northern Malawi. We linked information on HIV test results to subsequent self-reported HIV status, and calculated sensitivity, specificity, positive predictive value and negative predictive value for self-reported HIV status (considered as a diagnostic test). We used Poisson regression with robust variance estimators to examine predictors of accurate self-reporting of HIV-positive status.

RESULTS

Among 17 445 adults who tested for HIV, were recorded as having received their HIV test results, and had a subsequent self-reported HIV status between 2007 and 2018: positive predictive value of self-reported HIV status was 98.0% (95% confidence interval: 97.3-98.7); negative predictive value was 98.3 (98.1-98.5); sensitivity was 86.1% (84.5-87.7); and specificity was 99.8% (99.7-99.9). Among true HIV-positive people, those who were younger, interviewed in community settings, and had tested for HIV longer ago were more likely to misreport their HIV-positive status.

CONCLUSION

In this setting, self-report provides good estimates of test-detected HIV prevalence, suggesting that it can be used when HIV test results are not available. Despite frequent HIV testing, younger people and those interviewed in community settings were less likely to accurately report their HIV-positive status. More research on barriers to self-reporting of HIV status is needed in these subgroups.

Performance of verbal autopsy methods in estimating HIV-associated mortality among adults in South Africa

INTRODUCTION

Verbal autopsy (VA) can be integrated into civil registration and vital statistics systems, but its accuracy in determining HIV-associated causes of death (CoD) is uncertain. We assessed the sensitivity and specificity of VA questions in determining HIV status and antiretroviral therapy (ART) initiation and compared HIV-associated mortality fractions assigned by different VA interpretation methods.

METHODS

Using the WHO 2012 instrument with added ART questions, VA was conducted for deaths among adults with known HIV status (356 HIV positive and 103 HIV negative) in South Africa. CoD were assigned using physician-certified VA (PCVA) and computer-coded VA (CCVA) methods and compared with documented HIV status.

RESULTS

The sensitivity of VA questions in detecting HIV status and ART initiation was 84.3% (95% CI 80 to 88) and 91.0% (95% CI 86 to 95); 283/356 (79.5%) HIV-positive individuals were assigned HIV-associated CoD by PCVA, 166 (46.6%) by InterVA-4.03, 201 (56.5%) by InterVA-5, and 80 (22.5%) and 289 (81.2%) by SmartVA-Analyze V.1.1.1 and V.1.2.1. Agreement between PCVA and older CCVA methods was poor (chance-corrected concordance [CCC] <0; cause-specific mortality fraction [CSMF] accuracy ≤56%) but better between PCVA and updated methods (CCC 0.21-0.75; CSMF accuracy 65%-98%). All methods were specific (specificity 87% to 96%) in assigning HIV-associated CoD.

CONCLUSION

All CCVA interpretation methods underestimated the HIV-associated mortality fraction compared with PCVA; InterVA-5 and SmartVA-Analyze V.1.2.1 performed better than earlier versions. Changes to VA methods and classification systems are needed to track progress towards targets for reducing HIV-associated mortality.

Sustained 10-year gain in adult life expectancy following antiretroviral therapy roll-out in rural Malawi: July 2005 to June 2014

Background: Improved life expectancy in high HIV prevalence populations has been observed since antiretroviral therapy (ART) scale-up. However, it is unclear if the benefits are sustained, and the mortality among HIV-positive individuals not (yet) on ART is not well described. We assessed temporal change in mortality over 9 years in rural Malawi.

Methods: Within a demographic surveillance site in northern rural Malawi, we combined demographic, HIV and ART uptake data. We calculated life expectancy using Kaplan-Meier estimates, and compared mortality rates and rate ratios using Poisson regression, by period of ART availability (July 2005–June 2008, July 2008–June 2011 and July 2011–June 2014).

Results: Among 32 664 individuals there were 1424 deaths; 1930 individuals were known HIV-positive, of whom 1382 started ART. Overall, life expectancy at age 15 years increased by 10 years within 5 years of ART introduction, and plateaued. Age-standardized adult mortality rates declined from 11.3/1000 to 7.5/1000 person-years between the first and last time period. In July 2011-June 2014 compared with July 2005–June 2008, mortality declined in HIV-positive individuals on ART (rate ratio adjusted (aRR) for age, sex, location and education, 0.3; 95% confidence interval (CI) 0.2–0.5) and in those not (yet) on ART (aRR 0.3; 95%CI 0.1–0.5) but not in HIV-negative individuals (aRR 1.1; 95%CI 0.7–1.9).

Conclusions: Total population adult life expectancy increased toward that of HIV-negative individuals by 2011 and remained raised. The reduction in all-cause and HIV-related mortality in HIV-positive individuals not (yet) on ART suggests ART uptake is occurring at an earlier disease stage, particularly in women.

Determinants of time to antiretroviral treatment initiation and subsequent mortality on treatment in a cohort in rural northern Malawi

BACKGROUND

To optimise care HIV patients need to be promptly initiated on antiretroviral therapy (ART) and subsequently retained on treatment. In this study we report on the interval between enrolment and treatment initiation, and investigate subsequent attrition and mortality of patients on ART at a rural clinic in Malawi.

METHODS

HIV-positive individuals were recruited to a cohort study between January 2008 and August 2011 at Chilumba Rural Hospital (CRH). Outcomes were ascertained, up to 7 years after enrolment, through follow-up and by linkage to ART registers and the Karonga Health and Demographic Surveillance System (KHDSS). Kaplan-Meier methods and Cox regression were used to examine ART initiation after enrolment, mortality after ART initiation, and attrition after ART initiation.

RESULTS

Of the 617 individuals recruited, 523 initiated ART between January 2008 and January 2015. Median time from HIV testing to commencement of ART was 59 days (IQR: 10-330). By a year after enrolment 74.2 % (95 % CI 70.6-77.7 %) had initiated ART. Baseline clinical data at ART initiation and data on attrition was only available for the 438 individuals who initiated ART during active follow-up, between January 2008 and August 2011. Of these individuals, 6 were missing Ministry of Health numbers, leaving 432 included in analyses of attrition and mortality. At 4 years after ART initiation 71.3 % (95 % CI 65.7-76.2 %) of these patients were retained on treatment at the CRH and 17.2 % (95 % CI 13.8-21.4 %) had died. Participants who had a lower CD4 count at enrolment (≤350 cells/μl), enrolled in 2008, or tested for HIV at the CRH rather than through serosurveys, initiated treatment faster. Once on treatment, mortality rates were higher in patients who were HIV tested at the CRH, male, older (≥35 years), missing a CD4 count, or underweight (BMI < 18.5) at ART initiation.

CONCLUSIONS

Through linkage to the KHDSS and ART registers it was possible to continue follow-up beyond the end of the initial cohort study. Annual mortality after ART initiation remained considerable over a period of 4 years. Greater access to HIV and CD4 testing alongside initiation at higher CD4 counts, as planned in the test and treat strategy, could reduce this mortality.