Asthma and allergy medication use and costs among pediatric primary care patients on asthma controller therapy.

As observational studies in children initiating GINA-Step 3 therapies are scarce, we evaluated outcomes and costs in a primary care cohort. Two-yr retrospective cohort study included French children (age: 6-14) continuously followed in BKL-Thalès database who received > or =2 consecutive prescriptions for GINA-Step 3 therapy (=addition of montelukast or other controllers ('other'), such as increasing inhaled-corticosteroid dose (hICS), adding long-acting beta agonist (LABA), or ICS + LABA). After matching on gender and propensity score, medication use [rescue (short-acting beta agonists), acute (antibiotics (AB), oral corticosteroids (OCS)), allergy (antihistamines, nasal steroids) and other respiratory] was estimated via mean number of prescriptions and mean cost (per child/per month), and cost trends. During 12-month follow-up, children adding montelukast (n = 71) vs. 'other' (n = 213) had similar asthma rescue/acute and allergy medication use. Subgroup with asthma and allergic rhinitis (A + AR) adding montelukast used less OCS and AB (p = 0.014). Two-yr cost trends suggest stable asthma/allergy medication use in montelukast group (0.83 euro) compared with increase in 'other' (5.39 euro), which was driven by nasal steroid use [0.32 euro ('other') vs. -0.04 euro (montelukast), p = 0.0013]. In subgroup with A + AR decline in asthma/allergy medication use in montelukast group (-0.47 euro) vs. increase in 'other' (11.05 euro), p = 0.015, was driven by differences in AB and OCS (p = 0.04) and nasal steroid use (p = 0.001). Concomitant asthma/allergy medication use was similar in children adding montelukast or 'other' controllers (hICS, LABA, ICS + LABA), while children with allergic rhinitis on montelukast used less AB. Concomitant medication costs after addition of montelukast remained stable, while 'other' group experienced increase, especially in children with concomitant allergic rhinitis.