Introduction Much of the economic cost associated with severe asthma is related to the treatment of comorbidities, several of which arise from systemic steroid exposure related to asthma management. However these comorbidities may not progress equally across age-groups and genders following systemic steroid exposure.
Aim To examine the relationship between age-groups and gender in relation to prevalence of steroid induced comorbidity and the associated costs.
Methods Data for a cohort of 808 patients with severe asthma (SA) matched by age and sex with a cohort of 3,975 patients with a diagnosis of mild asthma and 2,412 non-asthma patients with a diagnosis of rhinitis were extracted from the Optimum Patient Care Research Database (OPCRD). Consultation data were used to identify comorbidities and conditional logistic regression analysis provided odds ratios (95% CI’s) for comorbidity risk between cohorts by age-group and gender. Prescription data for individual comorbidities was costed using Prescription Cost Analysis data from Northern Ireland and regressed upon cohort, age and gender.
Results Results presented below focus on a comparison between the non-asthma and severe asthma cohorts. Compared to older patients, younger patients in the SA cohort show significantly higher odds ratios relative to the non-asthma cohort for many comorbidities (Table 1). Apart from chronic kidney disease, hypercholesterolemia, osteoporosis and osteopenia, males with SA have higher odds ratios for all other comorbidities listed in Table 1 relative to non-asthma patients than females with SA. Upon examination of costs for individual comorbidities, males cost more than females for type II diabetes, hypertension, psychiatric disorders, while the opposite was observed for osteoporosis and osteopenia. Significant linear and non-linear increasing relationships were observed across age for costs related to type II diabetes, hypertension, hypercholesterolemia, dyspeptic disorders, cardiovascular disease, osteoporosis and osteopenia. Furthermore cost differentials for age and gender exhibited varying relationships across morbidities.
Conclusions The odds of having many steroid-induced comorbidities are higher among younger persons; differences between genders are also evident. While patients’ with SA cost significantly more than patients without steroid exposure or with mild steroid exposure, the distribution of the cost across age and gender varies across comorbidities.