Factors associated with uncontrolled asthma in adult asthmatics in Kinshasa, Democratic Republic of Congo

BACKGROUND: The ultimate goal of asthma treatment is long-term control. Uncontrolled asthma is a major public health problem worldwide, but there is a lack of data on asthma control and its causes in the Democratic Republic of Congo (DRC). OBJECTIVE: To determine the socio-demographic, environmental, clinical, and biological factors and comorbidities associated with uncontrolled adult asthma in Kinshasa, DRC. METHODS: We performed a cross-sectional study of 216 male and female asthmatics aged 18 and over consecutively recruited from tertiary clinics and the community in Kinshasa between June 2017 and February 2018. For each subject, socio-demographic, clinical, para clinical and environmental data were recorded. Forced Expiratory Volume in one second (FEV(1)) values were obtained by Spirometry, allergen testing performed using the skin prick test, serum vitamin D levels measured by radioimmunoassay, and asthma control assessed using the asthma control test (ACT) score. Multiple logistic regression identified factors associated with uncontrolled asthma. RESULTS: The average age of participants was 45.2 (SD 17.6) years, 74% were female, and 42% had a low educational level. Among all asthmatics, the prevalence of uncontrolled asthma was 56%, abnormal serum vitamin D level 95%, abnormal FEV(1) 65%, sensitization to two allergens (cat dander and dust mites) 18%, sleep disorders 37%, and heartburn 60%. Male (aOR 2.24; 95% CIs 1.04–4.79), low educational level (aOR 3.26; 95% CIs 1.54–6.67), sensitization to both cat dander and dust mites (aOR 2.67; 95% CIs 1.16–6.14), FEV(1) ≤80% (aOR 2.07; 95% CIs 1.08–3.96), abnormal serum vitamin D level (aOR 5.11; 95% CIs 1.17–22.33), sleep disorders (aOR 1.96; 95% CIs 1.04–3.71), and heartburn (aOR 2.02; 95% CIs 1.04–3.92) were significantly associated with uncontrolled asthma. CONCLUSION: Uncontrolled asthma is common in Kinshasa, and these factors associated with uncontrolled asthma may be considered as targets for future intervention strategies.