Risk Factors and Determinants of Pulmonary Function Impairments in Chronic Respiratory Diseases in Ethiopia: A Hospital-based Cross-Sectional Study

Abstract

Introduction: Chronic respiratory diseases (CRDs) are diseases of the airways and lung parenchyma. Although they are leading causes of morbidity and mortality globally, chronic respiratory diseases have received relatively little public attention. This study aimed to characterize the common chronic respiratory diseases, along with their lung function and possible determinants in symptomatic patients attending clinics at Bishoftu General Hospital, Ethiopia.
 Methods: A cross-sectional study was conducted at the outpatient department of Bishoftu Hospital from June 2019 to March 2020. Consecutive adult patients aged 18 and above with chronic respiratory symptoms (lasting more than 8 weeks) and no evidence of active tuberculosis were recruited. Questionnaires were used to collect data on demographics, symptoms, diagnoses, and potential risk factors. Lung function was measured by spirometry. Allergic status was assessed through allergen skin prick testing with standard allergens. 
 Results: A total of 170 participants were recruited, with the majority being female (102, 60.0%). The mean age was 49 years (SD=16). The most common symptoms reported were wheezing in the last twelve months 156 (91.8%), cough 138 (81.2%) and severe exertional breathlessness 137 (80.6%). Thirty-nine (22.9%) participants were either active or passive smokers. Half of the patients (50.3%) were exposed daily to vapors, dust, gases, or fumes and 58 (34.3%) were exposed to biomass smoke. In total, 138 (81.2%) had a positive allergen skin prick test. Chronic bronchitis (49.1%) and asthma (36.1%) were the most common clinical diagnoses. Classification of lung function revealed 23 (15%) normal, 29 (19%) obstructive, 36(23.5%) restrictive and 61(39.9%) mixed obstructive/ restrictive patterns. Airflow obstruction (FEV1/FVC ratio) was independently associated with increasing age (p<0.05), exertional breathlessness (p<0.001), previous history of asthma (p<0.05), BMI (p<0.05), and doctordiagnosed chronic obstructive pulmonary disease (p<0.001) and asthma (p<0.05).
 Conclusion: This study demonstrated a high burden of abnormal lung function in patients attending clinics due to chronic respiratory symptoms. Increasing age, exertional breathlessness, prior diagnosis of asthma, BMI, and clinically diagnosed COPD and asthma were independently associated with obstructed lung function. These find ings highlight the critical need for spirometry services to identify lung abnormalities in patients with chronic respiratory symptoms. Epidemiology, and the findings should be factored into clinical decision making and program design for disease prevention, screening, and treatment. It also calls for further prospective research to learn more about the conditions in the context of additional relevant personal and clinical characteristics.