Changes in mortality patterns and associated socioeconomic differentials in a rural South African setting: findings from population surveillance in Agincourt, 1993-2013

A thesis submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy (by publications) 20th December 2017.Understanding a population’s mortality and disease patterns and their determinants is important for setting locally-relevant health and development priorities, identifying critical elements for strengthening of health systems, and determining the focus of health services and programmes. This thesis investigates changes in socioeconomic status (SES), cause composition of overall mortality and the socioeconomic patterning of mortality that occurred in a rural population in Agincourt, northeast South Africa over the period 1993-2013 using Health and Demographic Surveillance Systems (HDSS) data. It also assesses the feasibility of applying record linkage techniques to integrate data from HDSS and health facilities in order to enhance the utility of HDSS data for studying mortality and disease patterns and their determinants and implications in populations in resource-poor settings where vital registration systems are often weak. Results show a steady increase in the proportion of households that own assets associated with greater modern wealth and convergence towards the middle of the SES distribution over the period 2001-2013. However, improvements in SES were slower for poorer households and persistently varied by ethnicity with former Mozambican refugees being at a disadvantage. The population experienced steady and substantial increase in overall and communicable diseases related mortality from the mid-1990s to the mid-2000s, peaking around 2005-07 due to the HIV/AIDS epidemic. Overall mortality steadily declined afterwards following reduction in HIV/AIDS-related mortality due to the widespread introduction of free antiretroviral therapy (ART) available from public health facilities. By 2013, however, the cause of death distribution was yet to reach the levels it occupied in the early 1990s. Overall, the poorest individuals in the population experienced the highest mortality burden and HIV/AIDS and tuberculosis mortality persistently showed an inverse relation with SES throughout the period 2001-13. Although mortality from non-communicable diseases (NCDs) increased over time in both sexes and injuries were a prominent cause of death in males, neither of these causes of death showed consistent significant associations with household SES. A hybrid approach of deterministic followed by probabilistic record linkage, and the use of an extended set of conventional identifiers that included another household member’s first name yielded the best results for linking data from the Agincourt HDSS and health facilities with a sensitivity of 83.6% and a positive predictive value (PPV) of 95.1% for the best fully automated approach. In general, the findings highlight the need to identify the chronically poorest individuals and target them with interventions that can improve their SES and take them out of the vicious circle of poverty. The results also highlight the need for integrated health-care planning and programme delivery strategies to increase access to and uptake of HIV testing, linkage to care and ART, and prevention and treatment of NCDs especially among the poorest individuals to reduce the inequalities in cause-specific and overall mortality. The findings also contribute to the evidence base to inform further refinement and advancement of the health and epidemiological transition theory. Furthermore, the findings demonstrate the feasibility of linking HDSS data with data from health facilities which would facilitate population-based investigations on the e↵ect of socioeconomic disparities in the utilisation of healthcare services on mortality risk. Keywords Agincourt Cause of death composition Epidemiological Transition Health and Demographic Surveillance System (HDSS) Household assets HIV/AIDS Index of Inequality InterVA Mortality Non-communicable Diseases Population Surveillance Record linkage Rural Socioeconomic Status South Africa Verbal Autopsy Wealth IndexLG201

The impact of HIV/AIDS on under-five mortality in Malawi

Magister Scientiae - MScAlthough the under-five mortality rate in Malawi has been declining since 1960, it still remains one of the highest in the world. In order to appropriately target interventions to achieve substantial reductions in deaths among children under the age of five years in Malawi, there is an ongoing need for better knowledge of the proportion of cause-specific under-five mortality in the country. The aim of this study was to estimate the direct contribution of HIV/AIDS to the observed level of under-five mortality in Malawi during the period 2000 to 2004.South Afric

Clustering South African households based on their asset status using latent variable models

The Agincourt Health and Demographic Surveillance System has since 2001 conducted a biannual household asset survey in order to quantify household socio-economic status (SES) in a rural population living in northeast South Africa. The survey contains binary, ordinal and nominal items. In the absence of income or expenditure data, the SES landscape in the study population is explored and described by clustering the households into homogeneous groups based on their asset status. A model-based approach to clustering the Agincourt households, based on latent variable models, is proposed. In the case of modeling binary or ordinal items, item response theory models are employed. For nominal survey items, a factor analysis model, similar in nature to a multinomial probit model, is used. Both model types have an underlying latent variable structure - this similarity is exploited and the models are combined to produce a hybrid model capable of handling mixed data types. Further, a mixture of the hybrid models is considered to provide clustering capabilities within the context of mixed binary, ordinal and nominal response data. The proposed model is termed a mixture of factor analyzers for mixed data (MFA-MD). The MFA-MD model is applied to the survey data to cluster the Agincourt households into homogeneous groups. The model is estimated within the Bayesian paradigm, using a Markov chain Monte Carlo algorithm. Intuitive groupings result, providing insight to the different socio-economic strata within the Agincourt region.Comment: Published in at http://dx.doi.org/10.1214/14-AOAS726 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

Care pathways during a child's final illness in rural South Africa: Findings from a social autopsy study.

BACKGROUND: Half of under-5 deaths in South Africa occur at home, however the reasons remain poorly described and data on the care pathways during fatal childhood illness is limited. This study aimed to better describe care-seeking behavior in fatal childhood illness and to assess barriers to healthcare and modifiable factors that contribute to under-5 deaths in rural South Africa. METHODS: We conducted a social autopsy study on all under-5 deaths in two rural South African health and demographic surveillance system sites. Descriptive analyses based on the Pathways to Survival Framework were used to characterise how caregivers move through the stages of seeking and providing care for children during their final illness and to identify modifiable factors that contributed to death. FINDINGS: Of 53 deaths, 40% occurred outside health facilities. Rates of antenatal and perinatal preventative care-seeking were high: over 70% of mothers had tested for HIV, 93% received professional assistance during delivery and 79% of children were reportedly immunised appropriately for age. Of the 48 deaths tracked through the stages of the Pathways to Survival Framework, 10% died suddenly without any care, 23% received home care of whom 80% had signs of severe or possibly severe illness, and 85% sought or attempted to seek formal care outside the home. Although half of all children left the first facility alive, only 27% were referred for further care. CONCLUSIONS: Modifiable factors for preventing deaths during a child's final illness occur both inside and outside the home. The most important modifiable factors occurring inside the home relate to caregivers' recognition of illness and appreciation of urgency in response to the severity of the child's symptoms and signs. Outside the home, modifiable factors relate to inadequate referral and follow-up by health professionals. Further research should focus on identifying and overcoming barriers to referral

Time to review policy on screening for, and managing, hypertension in South Africa : evidence from primary care

Background Current policy in South Africa requires measurement of blood pressure at every visit in primary care. The number of patients regularly visiting primary care clinics for routine care is increasing rapidly, causing long queues, and unmanageable workloads. Methods We used data collected during a randomised control trial in primary care clinics in South Africa to estimate how changes in policy might affect workloads and improve identification of undiagnosed hypertension. Results The prevalence of raised blood pressure increased with age; 65% of individuals aged over 60 years had a raised blood pressure, and 49% of them were not on any treatment. Over three months, eight health facilities saw 8,947 individual chronic disease patients, receiving 22,323 visits from them. Of these visits, 60% were related to hypertension, with or without HIV, and a further 35% were related to HIV alone. Long waits for blood pressure checks caused friction at all levels of the clinics. Blood pressure machines frequently broke down due to heavy use, and high blood pressures readings were often ignored. If chronic disease patients without a diagnosis of hypertension had their blood pressure checked only once a year, the number of checks would be reduced by more than 80%. Individuals with hypertension had a blood pressure check on average once every 7 weeks, but South African guidelines recommend that this should be done every 3 months at most. Conclusions The numbers of chronic disease patients in primary care clinics in South Africa is rising rapidly. New policies for measuring blood pressure in these patients attending clinics are urgently needed

Misreporting of Patient Outcomes in the South African National HIV Treatment Database: Consequences for Programme Planning, Monitoring, and Evaluation.

Background: Monitoring progress toward global treatment targets using HIV programme data in sub-Saharan Africa has proved challenging. Constraints in routine data collection and reporting can lead to biased estimates of treatment outcomes. In 2010, South Africa introduced an electronic patient monitoring system for HIV patient visits, TIER.Net. We compare treatment status and outcomes recorded in TIER.Net to outcomes ascertained through detailed record review and tracing in order to assess discrepancies and biases in retention and mortality rates. Methods: The Agincourt Health and Demographic Surveillance System (HDSS) in north-eastern South Africa is served by eight public primary healthcare facilities. Since 2014, HIV patient visits are logged electronically at these clinics, with patient records individually linked to their HDSS record. These data were used to generate a list of patients >90 days late for their last scheduled clinic visit and deemed lost to follow-up (LTFU). Patient outcomes were ascertained through a review of the TIER.Net database, physical patient files, registers kept by two non-government organizations that assist with patient tracing, cross-referencing with the HDSS records and supplementary physical tracing. Descriptive statistics were used to compare patient outcomes reported in TIER.Net to their outcome ascertained in the study. Results: Of 1,074 patients that were eligible for this analysis, TIER.Net classified 533 (49.6%) as LTFU, 80 (7.4%) as deceased, and 186 (17.3%) as transferred out. TIER.Net misclassified 36% of patient outcomes, overestimating LTFU and underestimating mortality and transfers out. TIER.Net missed 40% of deaths and 43% of transfers out. Patients categorized as LTFU in TIER.Net were more likely to be misclassified than patients classified as deceased or transferred out. Discussion: Misclassification of patient outcomes in TIER.Net has consequences for programme forecasting, monitoring and evaluation. Undocumented transfers accounted for the majority of misclassification, suggesting that the transfer process between clinics should be improved for more accurate reporting of patient outcomes. Processes that lead to correct classification of patient status including patient tracing should be strengthened. Clinics could cross-check all available data sources before classifying patients as LTFU. Programme evaluators and modelers could consider using correction factors to improve estimates of outcomes from TIER.Net

Challenges with tracing patients on antiretroviral therapy who are late for clinic appointments in rural South Africa and recommendations for future practice.

Background: It is common practice for HIV programmes to routinely trace patients who are late for a scheduled clinic visit to ensure continued care engagement. In South Africa, patients who are late for a scheduled visit are identified from clinic registers, and called by telephone up to three times by designated clinic staff, with home visits conducted for those who are unreachable by phone. It is important to understand outcomes among late patients in order to have accurate mortality data, identify defaulters to attempt to re-engage them into care, and have accurate estimates of patients still in care for planning purposes.Objective: We conducted a study to assess whether tracing of HIV patients in clinics in rural north-eastern South Africa was implemented in line with national policies.Methods: Thirty-three person-day of observations took place during multiple visits to eight facilities between October 2017 and January 2018 during which clinic tracing processes were captured. The facility level implementation processes were compared to the intended tracing process and gaps and challenges were identified.Results: Challenges to implementing effective tracing procedures fell into three broad categories: i) facility-level barriers, ii) issues relating to data, documentation and record-keeping, and iii) challenges relating to the roles and responsibilities of the different actors in the tracing cascade.We recommend improving linkages between clinics, improving record-keeping systems, and regular training of community health workers involved in tracing activities. Improved links between clinics would reduce the chance of patients being lost between clinics. Record-keeping systems could be improved through motivating health workers to take ownership of their data and training them on the importance of complete data. Finally, training of community health workers may improve sustained motivation, and improve their ability to respond appropriately to their clients' needs.Conclusions: Substantial investment in data infrastructure and healthcare staff training is needed to improve routine tracing

The impact of HIV status on the distance traveled to health facilities and adherence to care. A record-linkage study from rural South Africa.

BACKGROUND: For people living with HIV (PLWH), the burden of travelling to a clinic outside of one's home community in order to reduce the level of stigma experienced, may impact adherence to treatment and accelerate disease progression. METHODS: This study is set in the Agincourt Health and Demographic Surveillance System (HDSS) in South Africa. Probabilistic and interactive methods were used to individually link HDSS data with medical records. A regression analysis was used to assess whether travel distance was correlated with the condition for which individuals were seeking care (primarily HIV, diabetes or hypertension). For PLWH, a Cox proportional hazard regression model was used to test for an association between the distance travelled to the clinic and late attendance at follow-up visits. RESULTS: The adjusted relative risk (RR) of travelling to a clinic more than 5 km from that nearest to their home for HIV patients compared to those being treated for other conditions was 2.78 (95% confidence interval (CI) = 2.23-3.48). The adjusted Cox regression model showed no evidence for an association between the distance travelled to a clinic and the rate of late visits. (RR = 1.00, 95% CI = 0.99-1.00). CONCLUSIONS: The findings were consistent with the hypothesis that people living with HIV/AIDS would be willing to accept the burden of increased clinic travel distances in order to maintain anonymity and so limit their exposure to stigma from fellow community members. For those seeking HIV care the lack of an association between increased travel distances and late visit attendance suggests this may not impact treatment outcomes

Patterns of engagement in HIV care during pregnancy and breastfeeding: findings from a cohort study in North-Eastern South Africa.

BACKGROUND: Eliminating mother-to-child transmission of HIV (MTCT) in sub-Saharan Africa is hindered by limited understanding of HIV-testing and HIV-care engagement among pregnant and breastfeeding women. METHODS: We investigated HIV-testing and HIV-care engagement during pregnancy and breastfeeding from 2014 to 2018 in the Agincourt Health and Demographic Surveillance System (HDSS). We linked HIV patient clinic records to HDSS pregnancy data. We modelled time to a first recorded HIV-diagnosis following conception, and time to antiretroviral therapy (ART) initiation following diagnosis using Kaplan-Meier methods. We performed sequence and cluster analyses for all pregnancies linked to HIV-related clinic data to categorise MTCT risk period engagement patterns and identified factors associated with different engagement patterns using logistic regression. We determined factors associated with ART resumption for women who were lost to follow-up (LTFU) using Cox regression. RESULTS: Since 2014, 15% of 10,735 pregnancies were recorded as occurring to previously (51%) or newly (49%) HIV-diagnosed women. New diagnoses increased until 2016 and then declined. We identified four MTCT risk period engagement patterns (i) early ART/stable care (51.9%), (ii) early ART/unstable care (34.1%), (iii) late ART initiators (7.6%), and (iv) postnatal seroconversion/early, stable ART (6.4%). Year of delivery, mother's age, marital status, and baseline CD4 were associated with these patterns. A new pregnancy increased the likelihood of treatment resumption following LTFU. CONCLUSION: Almost half of all pregnant women did not have optimal ART coverage during the MTCT risk period. Programmes need to focus on improving retention, and leveraging new pregnancies to re-engage HIV-positive women on ART

Factors influencing HIV care outcomes among adolescents living with HIV in rural South Africa

In the Agincourt Health and Socio-Demographic Surveillance System (HDSS) site in rural Mpumalanga Province, South Africa the Project SOAR team hypothesized that HIV status disclosure, individuals’ prior healthcare seeking experiences, history of depression and overall emotional well-being, experiences with domestic and intimate partner violence, and substance use could contribute to poor levels of treatment adherence among adolescents living with HIV. The overall objective of this study was to better understand HIV care outcomes among HIV-positive adolescents in the Agincourt HDSS in the era of universal test and treat so we can better inform HIV care programs targeting this vulnerable population