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Prediction of loss to follow-up in postpartum others living with HIV

Introduction: In South Africa, postpartum women living with HIV are at an increased risk of loss to follow-up, which poses a critical barrier in vertical transmission prevention. Previous studies have focused on the aetiology of loss to follow-up, with little emphasis on predictive methods. The aim...

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Main Author: Fielding, Christopher
Other Authors: Phillips, Tamsin
Format: Thesis
Language:English
English
Published: Department of Public Health and Family Medicine 2025
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access_status_str Open Access
author Fielding, Christopher
author2 Phillips, Tamsin
author_browse Fielding, Christopher
Phillips, Tamsin
author_facet Phillips, Tamsin
Fielding, Christopher
author_sort Fielding, Christopher
collection Thesis
description Introduction: In South Africa, postpartum women living with HIV are at an increased risk of loss to follow-up, which poses a critical barrier in vertical transmission prevention. Previous studies have focused on the aetiology of loss to follow-up, with little emphasis on predictive methods. The aim of this study was to use machine learning methods, applied to routine care data, to predict loss to follow-up among postpartum women living with HIV. Methods: This study is a secondary data analysis of 333 peripartum women living with HIV enrolled in the Routine Electronic Mother-Infant Data study in Gugulethu, Cape Town. Data from routine medical records obtained in the parent study were analysed using descriptive statistics, and several machine learning models.. An extreme gradient boosting model was developed and validated to predict the risk of loss to follow-up within the first 9 months postpartum based on routinely available patient data at the point of discharge after delivery. Model calibration was performed on the trained extreme gradient boosting model (n=233), and calibration performance validated on the validation dataset (n=100). Sensitivity and specificity trade-offs were examined and the Youden Index used to identify the optimal classification threshold (i.e., threshold that maximised sensitivity and specificity). Results: Key factors associated with being lost to follow-up included younger maternal age, shorter duration from HIV diagnosis to antiretroviral therapy initiation, and not actively being on antiretroviral therapy at estimated conception. The extreme gradient boosting model demonstrated an area under the receiver operating characteristic curve of 0.721 when validated on the validation dataset, indicating good predictive performance. Model calibration did not significantly improve when calibration methods were applied. Youden Index calculations indicated that the optimal classification threshold was 0.252, providing a sensitivity of 0.827 and a specificity of 0.634. Conclusions: This study emphasises the importance of antiretroviral associated behavioural and healthcare factors in predicting loss to follow-up among postpartum women living with HIV. The developed predictive model showed good predictive power and could assist healthcare providers in identifying high-risk individuals, allowing targeted preventative measures that cost-effectively improve vertical transmission prevention. Future research should focus on validating this model in larger and more diverse populations and integrating it into existing healthcare practices.
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provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2025
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spelling oai:open.uct.ac.za:11427/42156 Prediction of loss to follow-up in postpartum others living with HIV Fielding, Christopher Phillips, Tamsin Arua, Eke HIV Postpartum women lost to follow-up antiretroviral therapy predictive modelling Introduction: In South Africa, postpartum women living with HIV are at an increased risk of loss to follow-up, which poses a critical barrier in vertical transmission prevention. Previous studies have focused on the aetiology of loss to follow-up, with little emphasis on predictive methods. The aim of this study was to use machine learning methods, applied to routine care data, to predict loss to follow-up among postpartum women living with HIV. Methods: This study is a secondary data analysis of 333 peripartum women living with HIV enrolled in the Routine Electronic Mother-Infant Data study in Gugulethu, Cape Town. Data from routine medical records obtained in the parent study were analysed using descriptive statistics, and several machine learning models.. An extreme gradient boosting model was developed and validated to predict the risk of loss to follow-up within the first 9 months postpartum based on routinely available patient data at the point of discharge after delivery. Model calibration was performed on the trained extreme gradient boosting model (n=233), and calibration performance validated on the validation dataset (n=100). Sensitivity and specificity trade-offs were examined and the Youden Index used to identify the optimal classification threshold (i.e., threshold that maximised sensitivity and specificity). Results: Key factors associated with being lost to follow-up included younger maternal age, shorter duration from HIV diagnosis to antiretroviral therapy initiation, and not actively being on antiretroviral therapy at estimated conception. The extreme gradient boosting model demonstrated an area under the receiver operating characteristic curve of 0.721 when validated on the validation dataset, indicating good predictive performance. Model calibration did not significantly improve when calibration methods were applied. Youden Index calculations indicated that the optimal classification threshold was 0.252, providing a sensitivity of 0.827 and a specificity of 0.634. Conclusions: This study emphasises the importance of antiretroviral associated behavioural and healthcare factors in predicting loss to follow-up among postpartum women living with HIV. The developed predictive model showed good predictive power and could assist healthcare providers in identifying high-risk individuals, allowing targeted preventative measures that cost-effectively improve vertical transmission prevention. Future research should focus on validating this model in larger and more diverse populations and integrating it into existing healthcare practices. 2025-11-07T13:24:03Z 2025-11-07T13:24:03Z 2025 2025-11-04T10:31:36Z Thesis / Dissertation Masters MPH http://hdl.handle.net/11427/42156 en eng application/pdf Department of Public Health and Family Medicine Faculty of Health Sciences University of Cape Town
spellingShingle HIV
Postpartum women
lost to follow-up
antiretroviral therapy
predictive modelling
Fielding, Christopher
Prediction of loss to follow-up in postpartum others living with HIV
thesis_degree_str Master's
title Prediction of loss to follow-up in postpartum others living with HIV
title_full Prediction of loss to follow-up in postpartum others living with HIV
title_fullStr Prediction of loss to follow-up in postpartum others living with HIV
title_full_unstemmed Prediction of loss to follow-up in postpartum others living with HIV
title_short Prediction of loss to follow-up in postpartum others living with HIV
title_sort prediction of loss to follow up in postpartum others living with hiv
topic HIV
Postpartum women
lost to follow-up
antiretroviral therapy
predictive modelling
url http://hdl.handle.net/11427/42156
work_keys_str_mv AT fieldingchristopher predictionoflosstofollowupinpostpartumotherslivingwithhiv