Objective: To quantify persistence with inhaled corticosteroids (ICS) among new users in daily practice and identify determinants of persistence.
Methods: A retrospective cohort study was performed with data from the Dutch PHARMO system. This system consists of medication and hospital admission records of 325,000 inhabitants of 12 Dutch cities. In patients who were already using other drugs with a labeled indication of obstructive lung diseases (ATC: R03), individuals with a first dispensing of ICS between January 1, 1994 and December 31, 2000 were identified. Persistence with ICS was defined as the number of days on ICS treatment in the first year of use. Determinants of persistence were identified one year before start of the first dispensing of ICS.
Results: Approximately 50% of the patients used inhaled corticosteroids (ICS) for less than 200 days, while 18% continued treatment for one year. One-year persistence rates increased to 40% in patients with a history of multiple respiratory disease related drugs. Persistence rates also increased with lower initial doses, if the initial prescription was instituted by a medical specialist, if a patient was previously hospitalized for obstructive lung diseases, and with increasing age.
Conclusion: The persistence rate of ICS is poor. Preventing early treatment discontinuation may be important to ensure maximal benefit from ICS treatment.