Abstract
IntroductionAs life expectancy increases, the global burden of multimorbidity (the co-existence of two or more long-term conditions) is increasing. People in sub-Saharan Africa suffer from a dual burden of highly prevalent communicable and non-communicable diseases. In these settings, limited access to primary healthcare results in under-diagnosis; under-treatment; and, frequently, acute hospital admission as the sentinel presentation of multimorbidity. However, epidemiological data on multimorbidity in African hospital settings are scarce. These data are required to understand how health systems should be designed to meet these emergent needs. Within this thesis, I aim to provide a detailed description of the burden, disease constituents and outcomes of multimorbidity amongst patients admitted to hospital in Malawi and Tanzania.
Breathlessness is a common reason for hospital admission worldwide, and is associated with poor survival, particularly in low-resource settings. However, there are limited data on aetiology or long-term outcomes of breathlessness in sub-Saharan Africa, which is crucial to improve diagnostic and management strategies for this complex syndrome. Within this thesis, I therefore also aimed to examine this syndrome in more detail to characterise aetiological phenotypes, health outcomes, and to assess the diagnostic accuracy of biomarkers for common conditions that result in breathlessness-related hospitalisations.
Methods
Through a systematic review and meta-analysis, I reviewed the existing literature on multimorbidity and chronic disease in sub-Saharan Hospitals, and estimated prevalence of pre-selected conditions within unselected medical inpatient settings and emergency departments. The findings of this review contributed to the design of a prospective multicentre cohort study to describe multimorbidity among adults (≥18 years) admitted to hospital with acute medical conditions in Malawi and Tanzania. This study captured the prevalence of human immunodeficiency virus infection; diabetes mellitus; hypertension; and chronic kidney disease (the most common individual constituent diseases for multimorbidity) using point-of-care tests; self-reported and clinical diagnoses for additional chronic conditions; health related quality of life and cost implications associated with multimorbidity; and 90-day outcomes. Finally, participants with breathlessness in Malawi were enrolled into a nested cohort study and underwent systematic diagnostic evaluation using internationally accepted diagnostic criteria. I estimated disease prevalence; survival, health-related quality of life and functional status for one-year post admission; and diagnostic accuracy of natriuretic peptides for heart failure, and procalcitonin and C-reactive peptide for pneumonia.
Results
In the systematic literature review, of 61 manuscripts that met inclusion criteria, no studies reported multimorbidity data in sub-Saharan hospital settings but instead focused on individual diseases. Among patients admitted to medical wards, the most prevalent chronic diseases were human immunodeficiency virus infection (36.4%; 95% CI: 31.3–41.8); hypertension (24.4%; 95% CI: 16.7–34.2); diabetes (11.9%; 95% CI: 9.9–14.3); heart failure (8.2%; 95% CI: 5.6–11.9); chronic kidney disease (7.7%; 95% CI: 3.9–14.7); and stroke (6.8%; 95% CI: 4.7–9.6).
In the cohort study, 1407 adults admitted with acute medical conditions were recruited. Systematic evaluation of chronic diseases detected multimorbidity in 47.0% (473 of 1007 participants directly admitted from community settings). Adjusted 90-day mortality was higher in participants with multimorbidity (41.7% [335/804]) compared to those with no long-term conditions (13.5% [31/230]; HR 1.5 [95% CI 1.1-2.1]). Survivors at follow-up with multimorbidity had lower health-related quality of life compared to those with no long-term conditions (p=0.006).
In the nested cohort study, 44% met the case definition for breathlessness (334 of 751 acute medical admissions), and 316 underwent enhanced diagnostic evaluation. One-year mortality was higher in breathless patients (51% [157/307]) than those without (26% [100/385]); adjusted hazard ratio 1.8 [95% CI 1.4-2.3]. This study identified high prevalence and mortality of heart failure (35% [112/316] prevalence; 69% [75/109] one-year mortality), anaemia (40% [126/316]; 57% [70/122]), pneumonia (41% [131/316]; 53% [68/129]), and tuberculosis (29% [91/316]; 47% [41/87]). Most participants (63% [199/316]) had multiple diagnoses. Diagnostic accuracy (AUC) for heart failure was 0.89 (BNP) and 0.88 (NT-proBNP); for pneumonia, CRP was 0.77 and PCT 0.69.
Discussion
In this thesis, I present the first studies of multimorbidity and breathlessness among adults admitted to medical ward settings in sub-Saharan Africa. Multimorbidity and breathlessness presentations are common, characterised by overlapping and highly prevalent communicable and non-communicable diseases, and associated with increased mortality and low health-related quality of life. Health systems designed for the treatment of single diseases frequently overlook the needs of these patients, which may lead to under-treatment and potentially preventable mortality. Interventional studies are urgently needed
to design and evaluate integrated, patient-centred models of healthcare delivery with effective linkage between primary and secondary care. Additionally, further research is required to investigate appropriate mechanisms for long-term, horizontally delivered, community follow up.
| Date of Award | 24 Oct 2025 |
|---|---|
| Original language | English |
| Awarding Institution |
|
| Supervisor | Jamie Rylance (Supervisor), Benjamin Morton (Supervisor), Stephen Gordon (Supervisor) & Paul Dark (Supervisor) |