A recent European study has highlighted the significant impact of oral glucocorticoid treatment on the cost of treating patients with asthma in Sweden.^[1]  The observational study was based on healthcare records (primary and secondary care) and Swedish national health service registries for a cohort of over 15,000 asthma patients.

Asthma is one of the most common non-infectious respiratory diseases worldwide and affects some 8% of the Swedish population (0.8 million of a total population of 10.6 million). In Sweden, some 5% of all asthma patients have severe asthma (approximately 42,000 patients). This is compared to an average of 5-10% of asthma sufferers in other countries. International guidelines recommend limiting the use of oral corticosteroids (OCS) to short courses to control acute exacerbations and for severe patients who are clinically uncontrolled or at risk of loss of control despite the use of high-dose inhaled steroids and another controller. Despite this, the evidence shows that up to 60% of severe asthmatics receive chronic systemic steroid treatment, increasing their risk of experiencing adverse events associated with the use of oral glucocorticoids.^[1,2]

The databases used in the study were selected to ensure the cohort was representative of the Swedish population, and included a mix of rural and urban populations as well as public and private medical providers of different practice sizes. All patient data included in the study were from adults (≥18 years of age) with a diagnosis of asthma receiving their first claims record for respiratory medications between 2007-2009. Data from the first 12 months of treatment provided baseline characteristics such as lung function, medication and comorbidities for each patient, and records were analyzed for up to six years. Patients were categorized into three groups based on their baseline oral steroid use as follows:

• Regular-users = oral glucocorticoid therapy claims equivalent to ≥5mg/day for 365 days
• Periodic-user = oral glucocorticoid therapy claims equivalent to ≤5mg/day
• Non-users = no oral glucocorticoid therapy claims

The study aimed to investigate healthcare resource utilization (HCRU) and costs associated with real-world treatment of asthma. Medication used during the study included: oral corticosteroids, inhaled steroids (ICS), short-acting β2 antagonists (SABA) and long-acting muscarinic antagonists (LAMA), sometimes in combination with inhaled steroids. Lung function results were taken from medical records and expressed as FEV1% (forced expiratory volume as a percentage of the predicted value); where patients had more than one reading each year, the highest reading was taken. While the study didn’t split the patients out in terms of asthma severity, it did note that the definition of asthma severity could be aligned with the severity of the treatment required to control symptoms and as such, the regular-user group could be considered to have severe asthma.

Regular oral steroid use doubles healthcare costs for asthma patients

Of the 15,437 asthma patients included in the study, only 223 (1.4%) were regular-users at baseline, 19.7% periodic-users and the majority (78.7%) were non-users. The mean age of the cohort was 47.8 years, the majority (62.6%) were female, and the median follow up was 5.7 years. When the regular oral steroid users were compared to the periodic- and non-users, they had/were:

• Older (62.3 compared to 49.4% and 47.2% respectively)
• Lower lung function scores and higher eosinophil counts, suggesting more severe disease
• Greater use of inhaled steroids (90% compared to 88% and 82% respectively)
• Greater use of combination therapies (e.g., long-acting β-antagonists with inhaled steroids)
• Greater incidence of comorbidities such as pneumonia, diabetes and depression

Almost half (46%) of the regular steroid-users remained regular-users throughout the duration of the study and 38% transitioned from needing regular steroid use to periodic oral steroid use.

The increased costs associated with regular steroid use compared to those for patients with lower steroid use were quite dramatic. As shown in Table 1 the mean, age-adjusted, direct healthcare costs for the regular-user group were twice that of the costs for treating periodic- or non-users. Primary care consultations were the major driver of costs in the non-user and periodic-user groups, while inpatient costs were the major driver for the regular-users group.

*Data weighted according to age group. Adapted from Janson et al. ^[1] with Euros converted to USD based on conversion rate on September 27,  2024 of 1.12 USD to the Euro.

Asthma-related costs were 10-12% of total healthcare costs across all the groups. Annual in-patient asthma-related costs were four times higher in the regular-user group compared to the other two groups. Costs directly associated with glucocorticoid comorbidities were three times higher in the regular-user group than in the non-user group and two times higher than in the periodic-user group. The regular-user cohort also accounted for nearly 80% of total yearly pneumonia costs and over 80% of the total outpatient costs.

The high costs associated with glucocorticoid comorbidities in the regular-use (or severe asthma) group are consistent with findings of an Italian pharmacogenomic study of the shadow costs of oral steroid-related side effects in severe asthma patients. That study found the cost of OCS-related adverse events in severe asthma patients to be 1.5 times higher than in patients with mild-moderate asthma and almost twice the cost for the non-asthma control group.^[2]

Taken together, these studies highlight the cost impact of chronic oral steroid use in asthma. In addition, the fact that many of the regular-use steroid patients were also receiving treatments designed to be steroid-sparing (such as long-acting β-antagonists), highlights that the use of steroid-sparing treatments alone is not enough to reduce steroid exposure in asthma.  

As highlighted in a recent insights paper, a combination of steroid-sparing therapies with personalized steroid-reduction strategies can successfully reduce steroid exposure, even in patients with severe eosinophilic asthma. While more research is required in broader asthma cohorts to optimize this strategy, the results offer the possibility of successful steroid tapering.

References

1. Janson C, Lisspers K, Stallberg B et. al. Health care resource utilization and cost for asthma patients regularly treated with oral corticosteroids – a Swedish observational cohort study (PACEHR).  Resp. Research 19:168-175 (2018). doi.org/10.1186/s12931-018-0855-3
2. Canonica GW, Colombo GL, Bruno GM et. al. Shadow cost of oral corticosteroids-related adverse events:  A pharmacoeconomic evaluation applied to real-life data from the Severe Asthma Network in Italy (SANI) registry.  World Allergy Organization Journal, 12: 29-35 (2019). doi: 10.1016/j.waojou.2018.12.001.