Teresa Espanol,1 Johan Prevot,2 Jose Drabwell,2 Seema Sondhi,3 Laurence Olding4 1Immunology Unit, Vall d’Hebron University Hospital, Barcelona, Spain; 2International Patient Organisation for Primary Immunodeficiencies, Cornwall, UK; 3Baxter Healthcare SA, Zurich, Switzerland; 4Bryter, London, UK Background: Subcutaneous or intravenous immunoglobulin replacement is the mainstay of treatment for most patients with primary immunodeficiency disease (PID). The purpose of this study was to gain an understanding of how existing PID therapies affect patient lives and to identify desired improvements to immunoglobulin treatments. Methods: An online questionnaire was made available through the International Patient Organisation for Primary Immunodeficiencies to patients with PID and their caregivers regarding current treatment satisfaction, living with PID, and patient preferences using a conjoint approach. Health-related quality of life was canvassed via questionnaires using the Short Form 12 Health Survey and EuroQoL 5 Dimensions. Results: A total of 300 responded to the survey (72% patients with PID and 28% caregivers) from across 21 countries, mostly the UK, Sweden, Canada, France, Germany, and Spain. Fifty-three percent and 45% of patients received intravenous and subcutaneous therapy, respectively. Most respondents (76%) were satisfied with their current treatment, reflecting the benefits that immunoglobulin therapy provides for patient health and well-being. However, patients remained below the physical and mental well-being norms for health-related quality of life as determined by the questionnaire. All respondents expressed a desire for 4-weekly infusions, the ability to administer these at home, self-administration, shorter duration of administration, and fewer needle sticks. Conclusion: The results of this survey highlight the importance of providing access to different treatment options and modes of administration to ensure individual patient needs are best met. Keywords: primary immunodeficiency, immunoglobulins, quality of life, patient needs, patient satisfaction, conjoint analysis