OBJECTIVES: REMS surveys seek to assess survey participants’ awareness and understanding of key risk messages of REMS programs and are thus critical to maintaining effective REMS programs. This study sought to examine REMS survey response rates by method of patient recruitment (i.e., mode of invitation delivery and source of patient contact information). METHODS:  This retrospective analysis of patient survey data, collected from all five REMS surveys conducted by a major CRO from 2014-2016, examined recruitment and survey completion metrics. Response rates were compared across two modes of invitation delivery and sources of patient contact information. Mode 1: sponsor-provided list of patients willing to be contacted regarding the product, but not necessarily product users; patient survey invitations were delivered via email with the survey link embedded. Mode 2): pharmacy claims data from a nationwide retail pharmacy chain; patient survey invitations were delivered via hardcopy mail to a targeted group of patients who filled prescriptions for the product in the last year. Surveys were available both online and via telephone. RESULTS: Using Mode 1, 19,650 surveys were distributed and 10,800 were distributed using Mode 2. Only 4.3% (n=1314) responded to the surveys. Regardless of recruitment method, the majority of patients (85%) completed the surveys online rather than via telephone. Response rates were higher for surveys using Mode 2 (7.4%) compared to surveys using Mode 1 (2.6%). CONCLUSIONS:  This study was limited in its ability to separate source of participant contact information from mode of invitation delivery. However, results suggest that specifically targeting product users (Mode 2) may play a larger role in survey response than consent or ease of participation - embedded link in emailed invitations (Mode 1). Further research is needed to compare response rates for pre-consented patients with and without product exposure.