PURPOSE: This study describes the prevalence of clinical phenotypes in a population of asthma patients referred to a regional specialist referral center in Northern Alberta.
METHODS: A retrospective chart review of 172 patients referred to the University of Alberta Hospital asthma clinic between 2003 to 2009 was performed. Subject demographics, co-morbidities, previous hospitalizations, and asthma management at the time of presentation were reviewed. Asthma severity was determined following an initial period of evaluation (assessment and optimization of patient management). Statistical analyses were performed using Chi-squared tests.
RESULTS: Of 172 referred patients, 128 met guidelines-based criteria for current asthma and were included for review. The average age in this patient population was 48 and 50 (39%) patients were male. 29 (23%) patients had severe asthma, and of these 17 (59%) were male. (p=0.01) Severe asthma was associated with greater prevalence of co-morbid diabetes (21% vs. 6%, p=0.02), gastroesophageal reflux disease (GERD) (55% vs. 24%, p<0.01), and current psychiatric illness (28% vs. 9%, p<0.01) as defined by DSM IV-TR criteria. There was a greater prevalence of rhinosinusitis (52% vs. 25%, p<0.01) among severe asthma patients. There were no gender differences noted in the overall prevalence of co-morbidities sub-categorized by severity (severe vs. moderate). Severe asthma patients also had greater incidences of prior hospitalizations (66% vs. 33%, p<0.01) at any point in their lifetime.
CONCLUSION: These findings were consistent with previous studies indicating that rhinosinusitis is associated with greater asthma severity. Psychiatric co-morbidities including depression and anxiety are more prevalent in severe asthma, supporting recent studies showing increased psychological stress and greater difficulty coping among patients with severe asthma.
CLINICAL IMPLICATIONS: Severe asthma patients, moreso than milder disease, should be carefully assessed for co-morbid disease as well as known clinical phenotypes. Escalation of asthma treatment should be carefully evaluated in the context of optimizing management of co-morbid illness. As well, it is important to consider that some of these patients' respiratory symptoms (dyspnea, cough) may be due to factors other than asthma alone.
DISCLOSURE: Charles Lim, No Financial Disclosure Information; No Product/Research Disclosure Information