Variable, Real-world Treatment Trajectories for Newly Diagnosed Asthma Patients

Real-world treatment regimens for asthma patients vary dramatically, according to a recently published paper by Markus et al.^[1]  The multinational study set out to address the lack of knowledge surrounding the management of patients with asthma and COPD in the real world. The authors aimed to generate data that could support the development of new hypotheses and enable future studies to address gaps in clinical practice.

This retrospective study used data from over 1.3 million asthma and COPD patients from six countries across three continents. The data were collected from four drug dispensing databases and four electronic health record databases. The study included all patients diagnosed between January 2010 and December 2019, with a minimum of one year of data pre-diagnosis and three years of follow-up post-diagnosis. The asthma cohort was restricted to patients aged 18 years and over. Treatment trajectories (the sequence of respiratory drug classes received over time) were studied at the drug class level rather than by individual drug.

The median follow-up was 5.6 years from first diagnosis. Baseline socioeconomic, demographic and clinical characteristics varied substantially across the 915,376 adults identified with asthma (Table 1). The Medicare cohort had both the oldest patients and the highest level of co-morbidities, with a Charlson comorbidity index of 2.4 compared to ≤1.4 for other databases. The results are consistent with Medicare’s provision of health insurance to people aged ≥65 and younger people with disabilities.  

Table 1: Demographics of patients included in the 8 databases used for the study. Adapted from Markus et. al. 2024

*Claims databases provided by IBM MarketScan
**Electronic health record database (general practice prescribing)
***Electronic health record database (hospital prescribing)

There were substantial differences in the proportion of patients receiving any treatment across the eight databases (range 66.8% to 92.7%). Spain, UK and Estonia were the top performers in this respect, with treatment rates over 92%. The Medicaid cohort had the lowest treatment levels at 66.8% and the second highest comorbidity score at 1.4.

Systemic and inhaled steroids remain in common use for asthma

The paper used “sunburst plots” to illustrate the first three lines of therapy for patients – with the inner circle representing first-line therapy and outer circles representing follow-on therapy lines. Color coding was used to represent the proportion of patients receiving different first-line therapies and therapy combinations. Treatment trajectories were plotted up to third-line for all databases.

A common thread across all cohorts was the use of oral corticosteroids (OCS) and inhaled corticosteroids, either as monotherapy (3.1%–27.9% across databases) or in combination with other agents, across all three treatment lines. The sunburst plots illustrated that steroid use was more widespread in the European countries (Estonia, Spain and the UK) than in South Korea and the United States.  

The study tells us the following about first-line therapies across the different cohorts:

• Short-acting β2 antagonists (SABA) were the most common first-line treatment across all cohorts (20.8%–47.4% of first-line treatments) with the exception of:
  • South Korea (AUSOM) where leukotriene receptor antagonists (LTRA) were most common
  • The frequent use of long-acting β2 antagonists in combination with inhaled corticosteroids (LABA-ICS) in Europe and systemic steroid bursts in the US
  • Estonia (EHIF), where LABA-ICS and inhaled glucocorticoids (ICS) monotherapy were frequently used in first-line

The authors attributed the differences seen between the databases to three main reasons:

• Different data captured
  • e.g., claims databases are based on dispensed drugs and may better reflect medication taken than prescription figures that can’t record if the prescription was fulfilled
• Different patient populations enrolled (age, socioeconomic group, etc.)
  • e.g., the lower treatment levels in the relatively poor socioeconomic Medicaid group could reflect that cohort’s difficulty consulting physicians to receive preventative medications.
• Differences between countries
  • e.g., variations in treatments recommended by different national guidelines, national health services versus private healthcare systems, etc.

They also noted that choice of first-line or follow-on treatment wasn’t always in line with national or international recommendations, and evidence of both step-up/step-down treatment, suggesting a degree of customization to treatment choices.

Future guidelines informed by real-world practices

This is the first global, large-scale characterization study to explore real-world treatment trajectories in adults with Asthma and COPD. Its strength lies in the size and diversity of the populations included and it provides a benchmark for future studies. As such, the study provides important insights into treatment practices around the world and how they differ from (inter)national guidelines. It also provides a foundation for further studies to improve clinical practice. 

Improvements in clinical practice require a better understanding of the reasons for the differences observed between clinical guidelines and treatment practices. Further research should also explore how treatment trajectories change over time and their impact on clinical outcomes, to better inform future guideline development.

The study also raises questions about the continued use of oral corticosteroids, in an era of increasing access to newer therapies, often heralded as “steroid sparing”, especially when clinicians now have the ability to measure and monitor steroid-toxicity using the STOX®  Suite.  

References

1. Markus AF, Rijnbeek PR, Kors JA et al.  Real-world treatment trajectories of adults with newly diagnosed asthma or COPD.  BMJ Open Respiratory Research:  11: e002127 (2024). doi:10.1136/bmjresp-2023-002127