Browsing by Subject "T2DM"

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    Open Access
    Application of dynamic prediction models for longitudinal biomarkers and clinical outcomes in low and middle-income settings
    (2025) Honwana, Frissiano Ernest; Myer, Benjamin; Lesosky, Elisa; Maia; Gumedze, Freedom
    Routine monitoring of individuals with chronic diseases offers valuable data for understanding disease progression and treatment effectiveness, often using biomarkers. With the modernisation of clinical care, prediction models have received greater attention in analysing such data. Prognosis prediction modelling approaches have been widely adopted, especially with digitising health records into electronic health records (EHRs). Dynamic prediction modelling has emerged as a critical approach, allowing real-time updates of prognosis predictions based on available data. However, there is a notable scarcity of dynamic prediction models applied to routine data from EHRs, particularly in contexts such as HIV and type 2 diabetes (T2DM) in resource-limited settings. Existing dynamic prediction models are typically developed and validated in data with comprehensive follow-ups and covariate collection, leading to the assumption of their universally improved predictive performance over traditional approaches such as the Cox proportional hazards-based prediction model. In addition to applying an extension of existing models to correctly model semicontinuous biomarker data (two-part joint model), this thesis challenges this assumption by applying dynamic prediction models using large routine data from EHRs generated in resource-limited settings, specifically focusing on using longitudinal biomarkers to predict probabilities of clinical outcomes in individuals with HIV or T2DM in South Africa. The predictive performance of this model is compared with that of the Cox proportional hazards-based prediction model and the two-part joint model. The prediction models had comparable predictive performances. The Cox proportional hazards-based prediction model had area under the curve (AUC) values ranging from 0.63 to 0.89 and Brier scores between 0.042 and 0.088 across routine T2DM and HIV data. The joint model had AUCs ranging between 0.66 and 0.73 and Brier scores between 0.033 and 0.089. The two-part joint model had AUCs and Brier scores closer to 0.6 and 0.1, respectively. These findings highlight the importance of adopting a conceptual approach to inform predictive performance, emphasising the need to account for context, type of disease, characteristics of a biomarker, and data characteristics. Such an approach will enhance individualised predictions using dynamic prediction models, potentially enabling recommendations for differentiated care and improving routine monitoring for individuals with chronic diseases, especially in resource-limited settings.
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    Open Access
    The Epidemiology of Auditory Dysfunction in Type 2 Diabetic Adults in Africa: 4 A Systematic Review and Meta-analysis
    (2022) Fihla, Achuma; Engel, Mark; Petersen, Lucretia; Hohlfeld, Ameer
    Background: There is a growing rate of diabetes related hearing loss (HL) worldwide. However, in under-developed countries, HL is still under-recognised as a complication of type 2 diabetes mellitus (T2DM). Although Africa presents a significant rise in T2DM every year, it is met with limited resources to assist its growing and ageing population. Objectives: This systematic review and meta-analysis brings awareness to diabetes-related HL in the form of reliable medical evidence measuring the prevalence of T2DM-related HL in an African population. Methods: Studies were screened using Rayyan QCRI. STATA software and the random-effects metaanalysis model was used to aggregate prevalence estimates with a 95% confidence interval. The Freeman Tukey Transformation was used to account for between study variability. The study protocol is published in PROSPERO international Register of Systematic Reviews (registration number CRD42021227801). Results: We identified a total of 99 studies, 14 duplicates were removed and 67 were excluded. After full review only five studies were included for quantitative synthesis. All the studied were crosssectional and used purposive sampling as their recruitment method. Conclusions: Findings show most participants with T2DM experienced mild HL and slight delays in objective hearing assessments. Audiometric resources and qualified Audiologists are scarce in Africa. Therefore, the available evidence does not justify the added costs needed for routine audiometric assessments for patients with T2DM. However, it does serve to recommend prioritising further research regarding risk factors associated with developing auditory disorders in people with T2DM.