Understanding treatment patterns and patient-reported outcomes associated with the use of authorized generics and corresponding independent generics across multiple therapeutic areas

Abstract

Objectives To assess patient characteristics, treatment patterns, and patient-reported outcomes (PROs) associated with authorized generics (AGs) and independent generics (IGs) use. Methods Prescription claims and National Health and Wellness Survey (NHWS) data were linked. Adults with billable national drug code (AG or IG), NHWS completion from June 2015 to July 2019, AG or IG on-hand at NHWS completion, and continuous insurance eligibility in 12 months pre- and post-NHWS completion were included. To be included, all unique medication formulations had to have at least one AG and one IG observation. PRO index date was NHWS completion; claims index date was defined as the first prescription claim identified during the 180-day period prior to NHWS completion for the same active ingredient and formulation type that was on-hand at NHWS completion. Results Patients (N = 20,229; 17.2% AG users) in six therapeutic areas (attention deficit-hyperactivity disorder [ADHD], antidepressants, beta blockers [BBs], calcium channel blockers [CCBs], statins, and thyroid) were included. Generally, AG (vs. IG) users were younger and differed in regional access and insurance type (all, p < .05). In multivariable analysis, significant differences were observed for presenteeism and overall work impairment (BBs), healthcare provider visits (BBs), and indirect costs (thyroid) (all, p < .05). AG and IG users differed in persistence (ADHD and statins; both, p < .05) and switch (BBs and CCBs; both, p < .01) rates. Conclusions PRO differences were often small in magnitude and varied by therapeutic area. The impact of switching should consider observed PRO differences, patient preferences, and market availability of AG and IG alternatives.