Risk factors for bronchial asthma exacerbations in patients presenting to Mulago Hospital

Abstract

Introduction: Asthma is a worldwide problem with an estimated 300 million people currently affected and a global prevalence ranging from 1% to 18%. Although asthma symptoms tend to be more prevalent in more affluent countries, they appear to be more severe in less affluent (developing) countries. Asthma exacerbations may be caused by a variety of risk factors and reducing exposure to some of these categories of risk factors improves the control of asthma and reduces medication needs. Knowledge of the particular risk factors precipitating bronchial asthma exacerbations in our patients is essential in formulating controlling and treatment protocols. Objective: This study aimed to determine the risk factors for asthma exacerbations in patients presenting to the emergency unit of Mulago Hospital Study methods: This study was an unmatched case-control study involving 43 cases and 43 controls. Asthma patients with exacerbations presenting to Mulago Hospital’s emergency unit were chosen as cases. The controls were asthma patients recruited from the outpatient department who had not had an exacerbation in the past 7 days. A structured questionnaire was used to interview patients concerning their possible exposure to certain risk factors. Variables: The study variables were age, sex, level of education, adherence to treatment, exercise, upper respiratory tract infections, household pets, smoking, strong emotions, exposure to in house wood or charcoal burning, weather, use of corticosteroids, beta-blockers and non steroidal anti-inflammatory drugs (NSAIDS). Analysis: Data analysis was done using SPSS Version 16. Univariate statistical analysis was done to assess the characteristics and risk factors of the participants. Multivariate methods were used to identify factors independently associated with exacerbations. Continuous data was summarized into means, while categorical variables were summarized into percentages or proportions. Results: Forty three cases and 43 controls were enrolled. Thirty two of the patients with asthma exacerbation (74.4%) had not used corticosteroids (oral or inhaled) in the past 7 days compared to 5 of the controls (11.6%) (OR =22.109; 95% Confidence interval (CI) 6.952 to 70.315; p<0.001). Patients with asthma exacerbations were younger (Mean age 32.86years SD 14.334) than the controls (Mean age 39.0 years SD 18.480) (p= 0.044) at bivariate analysis. Upper respiratory tract infections were significantly associated with exacerbations (OR 4.516; CI 1.258-16.213; p=0.018). All the other risk factors investigated were not significantly associated with exacerbations. Conclusions: Lack of corticosteroid use and upper respiratory tract infections were predictors of exacerbations in asthma patients presenting to the Accident and Emergency (A and E) unit of Mulago Hospital. Recommendation: The need to use inhaled corticosteroids as controller therapy for patients with asthma in Mulago Hospital should be emphasized among patients and health care providers.