Acute breathlessness as a cause of hospitalisation in Malawi: a prospective, patient-centred study to evaluate causes and outcomes

Abstract

Introduction: Breathlessness is a common cause of hospital admission globally and is associated with high mortality, particularly in low-income countries. In sub-Saharan Africa, there is a paucity of data on breathlessness, with existing data focused on individual diseases. There is a need for patient-centred approaches to understand interactions between multiple conditions to address population needs and inform health system responses. This multicentre prospective study in Malawi aimed to characterise the aetiologies, outcomes and biomarker accuracy for breathless patients.

Methods: Adults (aged ≥18 years) admitted to medical wards were consecutively recruited within 24 hours of hospital presentation and followed up for 1 year. Participants with breathlessness (defined as a composite of patient-reported shortness of breath; tachypnoea (respiratory rate ≥25/min); hypoxaemia (SpO₂ <94%) or treatment with oxygen) were systematically screened against internationally accepted diagnostic criteria. We estimated disease prevalence, survival, health-related quality of life and functional status. We also evaluated diagnostic accuracy of natriuretic peptides for heart failure, and procalcitonin (PCT) and C reactive peptide (CRP) for pneumonia.

Results: Of 751 participants, 44% (n=334) had breathlessness, and 316 underwent enhanced diagnostic screening. One-year mortality was higher in breathless patients (51% (157/307)) than those without (26% (100/385)); adjusted HR 1.8 (95% CI 1.4 to 2.3). We identified high prevalence and mortality of heart failure (35% (112/316) prevalence; 69% (75/109) 1-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 conditions. Diagnostic accuracy (area under the curve) for heart failure was 0.89 (brain natriuretic peptide) and 0.88 (N-terminal pro-B-type natriuretic peptide); for pneumonia, CRP was 0.77 and PCT was 0.69.

Discussion: Breathlessness-related hospital admissions in Malawi are common, multifactorial and associated with poor survival. This study demonstrates that co-existing conditions are common, highlighting the limitation of single-disease-focused health system responses. Integrated care pathways with context-sensitive diagnostic and treatment approaches are urgently needed to improve survival.

Keywords: clinical epidemiology; critical care; hypoxemia; pneumonia; respiratory infection; tuberculosis.