Evaluation of the utilization patterns of leukotriene modifiers in a large managed care health plan

To assess the utilization of leukotriene modifiers (LM) relative to national guidelines and to investigate possible emergency room utilization differences for LMs as monotherapy versus inhaled corticosteroid (ICS) monotherapy or combination ICS and LM therapy.

The utilization of leukotriene modifiers (montelukast sodium, zafirlukast, and zileuton), concurrent inhaled steroids (beclomethasone, budesonide, flunisolide, fluticasone, and triamcinolone), beta-agonists (albuterol, bitolterol, formoterol, isoetharine, levalbuterol, metaproterenol, pirbuterol, salmeterol, and terbutaline) and low-sedating antihistamines ([LSAs] cetirizine, desloratadine, fexofenadine, and loratadine) were assessed from the drug claims database of a large health insurer for dates of service for the 12-month period from September 1, 2001, through August 31, 2002. New-start LM patients were identified as having no previous LM drug claim within a 180-day look-back period from the first date of fill for the LM. Claims were stratified into age cohorts of.under 16 years. and.16 years and older. Emergency room (ER) claims for patients utilizing LMs, ICSs, and patients on both LM and ICS were retrieved for analysis from the medical claims database for the same 12-month study period.

More than 89% of new LM starts had no history of an ICS in the claims database. Overall, 61% of all (new and existing) LM patients did not have a claim for an ICS in their drug claims profile during the study period. An estimated 25% of LM utilization was not for asthma. No differences in ER utilization were found between ICS users and LM users; however, the ER utilization rate (0.090 ER visits per patient per year) was lower with combination therapy compared with monotherapy with ICS (0.110 ER visits per patient per year, P = 0.001) or LM (0.119 emergency room visits per patient per year, P<0.001).

The majority of LM use in this health plan was initial monotherapy, contrary to national treatment guidelines for asthma. At the time of the study, the apparent off-label use of LM for allergic rhinitis was significant for this health plan.