https://orcid.org/0000-0002-4185-4323
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Abstract
Purpose
The Global Initiative for Asthma (GINA) suggests a step-wise approach for pharmacological treatment of asthma. Valid study of real-world treatment patterns using dispensing databases includes proper measurement of medication adherence. We aim to explore such patterns by applying a time-varying proportion of days covered (tPDC)-based algorithm.
Patients and Methods
We designed a retrospective inception cohort study using the University of Groningen IADB.nl community pharmacy dispensing database. Included were 19,184 young adults who initiated asthma medication anywhere between 1994 and 2021, in the Netherlands. Main treatment steps were defined as: 1 - SABA/ICS-formoterol as needed, 2 - low dose ICS, 3 - low dose ICS + LABA or tiotropium, or intermediate dose ICS, 4 - intermediate to high dose ICS + LABA or tiotropium, triple therapy, or high dose ICS, 5 - treatment prescribed by a specialist. Changes in treatment steps were determined using a time-varying proportion of days covered (tPDC)-based algorithm. Individual drug treatment trajectories were visualized over time using a lasagna plot.
Results
At initiation, of the 19,184 included individuals, 52%, 7%, 15%, 16%, and 10% started treatment in steps 1 to 5, respectively. The median (IQR) follow-up time was 3 (1–7) years. Median (IQR) number of switches was 1 (0–3). Comparing starting step to last observed step, 37% never switched between treatment steps, 20% of individuals stepped down and 22% stepped up.
Conclusion
The low proportion of treatment switches between steps indicates that tailoring of treatment to patients’ needs might be suboptimal. The tPDC-based algorithm functions well in translating dispensing data into continuous drug-utilization data, enabling a more granular assessment of treatment patterns among asthma patients.
Abbreviations
ATC code, Anatomical Therapeutic Chemical code; COPD, chronic obstructive pulmonary disease; FDC, fixed-dose combination; GINA, Global Initiative for Asthma; ICS, inhaled corticosteroids; LABA, long-acting selective β2-adrenoreceptor agonist; LAMA, long-acting muscarinic antagonist; NHG, Dutch College of General Practitioners; SABA, short-acting selective β2-adrenoreceptor agonist; tPDC, time-varying proportion of days covered.
Data Sharing Statement
The data used for this study were provided by the University of Groningen IADB.nl community pharmacy dispensing database. Reasonable requests to access the data should be directed to the IADB (e-mail: [email protected]).
Ethics Approval and Informed Consent
The University of Groningen IADB.nl community pharmacy dispensing database contains data that is collected in accordance with the Dutch and European guidelines on privacy requirements (GDPR) for handling human data. Approval of the medical ethics committee was not needed nor required for this study.
Consent for Publication
No images or recordings were included in this manuscript that require consent for publication.
Acknowledgments
We would like to acknowledge the participating pharmacies for supplying their data for research purposes and the IADB.nl staff for data collection, maintenance, and providing us with the dataset.
Author Contributions
All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising, or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.
Disclosure
Dr Job FM van Boven reports grants and/or personal fees from AstraZeneca, Chiesi, GSK, Novartis, Teva, and Trudell Medical, outside the submitted work. The authors report no other conflicts of interest in this work.