Chronic Respiratory Disease Prevalence, Burden, and Treatment in Cape Town: A Cross-Sectional Study

Background and Aims: There is a high burden of respiratory symptoms in South Africa, but accurate classification of diagnoses is challenging. Due to the adverse risk profile, inhaled corticosteroid (ICS) treatment should only be used in specific conditions, such as asthma or chronic obstructive pulmonary disease (COPD) with eosinophilia. Those with tuberculosis or who are HIV-positive may be at particular risk. Hence, establishing underlying diagnoses and indications for ICS treatment is crucial. The primary aim was to establish the underlying diagnosis after investigations, the secondary aim was to identify any indication for ICS treatment (asthma or eosinophilia). 

Methods: We conducted a cross-sectional study of adults attending two hospitals in Cape Town, South Africa, with exacerbations of chronic respiratory diseases. Participants performed investigations at least 8 weeks after recruitment. Questionnaires and extensive investigations (full lung function with bronchodilator reversibility, allergy tests, computed tomography) were completed. 

Results: Between 2021 and 2023, a total of 224 participants were recruited, of whom 101 attended investigations, yet 40 died before they could attend. Most were current (49) or ex-smokers (40). A total of 46 previously had pulmonary tuberculosis. Post-tuberculosis lung disease (PTLD) with COPD (28) or COPD alone (27) were the most common diagnoses. Ten participants had asthma. Serum eosinophilia was present in 19 participants. There was no clear indication for ICS treatment for 5/7 participants who used ICS, and 22/30 who used ICS-long-acting beta-agonists combination. 

Conclusion: COPD and PTLD were more common, asthma and eosinophilia were less prevalent than expected. There was a high symptom burden. Modifiable risks (tuberculosis, smoking) were also common. ICS treatment appeared to be independent of underlying diagnosis and could lead to harm. Approximately 1 in 5 died shortly after admission. Strategies to better serve this patient group are urgently needed.