OBJECTIVES: To evaluate patient-reported treatment adherence in patients with asthma between two classes of asthma treatments, inhaled corticosteroids (IC) and leukotriene modifiers (LM). METHODS: Participants were identified via MediGuard, a novel digital patient platform where patients enroll online via the internet to be part of a digital patient community.  All information was obtained through participant self-report.  Between 2011 through 2013, MediGuard members with asthma were invited to complete the Medication Adherence Report Scale (MARS), a patient reported outcome (PRO) instrument that measures aspects of medication adherence.  MARS scores for high versus low adherence (i.e., scores ≥20 out of 25 indicate high adherence) were compared between the IC and LM groups using logistic regression analyses, adjusting for demographic variables, disease severity and number of concomitant medications. RESULTS: A total of 365 (IC) and 164 (LM) patients participated.  Age was similar between groups (mean [SD] = 58.7 [13.3] years vs. 57.7 [10.7] for IC and LM, respectively); and both groups were predominantly female (73.8% for IC; 79.0% for LM).  Disease severity and number of concomitant medications taken were similar between IC and LM groups.  Ninety-two percent (n=151) of the LM group had high levels of adherence according to the MARS versus 73% (n=265) of the IC group.  In multivariable analyses, patients taking LM had 4.6 (95% CIs: 2.5-8.5) times the odds of having high adherence to treatment versus patients taking IC. CONCLUSIONS: These results suggest higher adherence with oral versus inhaled agents in asthma after controlling for potential confounders.  Further exploration regarding why adherence differs between these classes is warranted.  In addition, investigations into how adherence may be enhanced and the impact of low adherence on treatment effectiveness should be performed.  Providing patients with information on adherence could help inform patients’ treatment decisions.