Published online: April 20, 2018
Asthma is a condition affecting approximately 334 million people worldwide. It gives rise to a significant disease burden in terms both of comorbidity and financial costs to which severe asthma is known to contribute disproportionately. Treatment of severe asthma may include high dose systemic-corticosteroid therapy which is also associated with substantial comorbidity. However, disentangling comorbidity, which is directly associated with asthma and that which is a result of corticosteroid exposure, has proven difficult. Examination of differences in this comorbidity burden across age, sex, and corticosteroid exposure in individuals with and without asthma can help shed light on this issue.
Barry and colleagues have recently published work in The Journal of Allergy and Clinical Immunology: In Practice examining the issue using two years of continuous administrative data on primary and secondary health care utilization and medication use by patients with severe asthma and high levels of systemic corticosteroid exposure (n = 808) from a UK primary care database (Optimum Patient Care Research Database (OPCRD)). The same healthcare data were extracted for age and sex matched patients with moderate/mild asthma and low systemic corticosteroid exposure (n = 3975) and patients without asthma and no exposure to systemic corticosteroids (n = 2412).
The prevalence of conditions associated with corticosteroid exposure (non-insulin dependent diabetes mellitus, obesity, osteoporosis, osteopenia, hypertension, chronic kidney disease, dyspeptic disorders, psychiatric disorders, sleep disorders, hypercholesterolemia, cataracts, cardiovascular disease, fractures, glaucoma) were compared between the three groups to see how levels of comorbidity varied by corticosteroid exposure and by age and sex, e.g. do younger male subjects (≤45 years) with high corticosteroid exposure have greater levels of these comorbid conditions compared to males ≤45 years with low levels of corticosteroid exposure? This healthcare utilization data was also monetized, and healthcare costs compared between the groups.
Younger individuals (≤45 years and 46-60 years) with high corticosteroid exposure were much more likely to experience many of these comorbid conditions when compared to younger individuals with low or no corticosteroid exposure whereas this difference was much less evident in older individuals (61-70 year and >70 years). There was also variation in specific comorbid conditions by sex. A similar pattern was also reflected in healthcare costs with individuals with high systemic corticosteroid exposure exhibiting higher healthcare costs although this difference tended to diminish in older age groups.
This pattern of difference in the prevalence of many comorbid conditions – wider at younger ages and converging at older ages – could be interpreted as corticosteroid exposure “bringing forward” the expression of conditions that in subjects with lower or no corticosteroid exposure tend to develop later in life. This analysis is cross-sectional, so we cannot confirm cause and effect between exposure and the early expression of comorbidity. More research is required to test this interpretation further. Clearly, however, clinicians and healthcare decision makers need to consider carefully the consequences of placing younger patients with severe asthma in particular on systemic corticosteroids. Newer corticosteroid-sparing therapies for achieving asthma control may be more expensive than these systemic corticosteroids however the lifetime cost of placing a younger individual on systemic corticosteroids may outweigh the cost of these new therapies.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.