The prevalence of asthma phenotypes in patients attending the chest clinic at Kenyatta National Hospital

Abstract

Background: Asthma is a heterogeneous disease characterized by distinct inflammatory and clinical phenotypes. Knowledge of these phenotypes enables individual patient targeted treatment resulting in better control leading to a reduction in treatment costs. Objective: To determine the prevalence of asthma phenotypes among adult asthmatics attending the chest out-patient clinic at Kenyatta National Hospital. Methodology: The study was a cross-sectional, descriptive study carried out on asthma patients attending chest clinic at KNH. The inclusion criteria was asthmatic patients, aged 13 years and above and had provided an informed consent/assent. The inflammatory phenotypes were determined using inflammatory cells in sputum. The clinical phenotypes were associated comorbidities which were determined from the case notes. Data Management: Data was analyzed using SPSS 21.0 software. Continuous data was analyzed into means and medians. Categorical data which included the asthma phenotypes and spirometry findings was presented as percentages. The prevalence of asthma phenotypes was analyzed as proportions using 95% CI. The results from spirometry were graded as mild, moderate, severe and very severe obstruction based on the spirometry findings of FEV1 and were presented as percentages. Results: Eighty one (81) asthma patients with an average age of 50.1 years and female predominance of 76.5% were studied. The prevalence of inflammatory phenotypes was paucigranulocytic (84%), mixed granulocytic (8.6%), neutrophilic (7.4%) and eosinophilic (0%). The prevalence of clinical phenotypes was allergic rhinitis (76.5%), atopy (67.9%) and GERD (54.3%). Conclusion: This study shows majorly paucigranulocytic phenotype which commonly has no target therapy, making routine use of inflammatory phenotyping in our patients not beneficial. Among the clinical phenotypes allergic rhinitis was the predominant clinical phenotype.