Balshaw, R, S Khorasheh, M Barbeau, S Kelly, S Flynn, O Heisel, and CR McBurney. “LONGITUDINAL OUTCOMES OF GASTROINTESTINAL SYMPTOMS IN CANADA (LOGIC): KEY FACTORS FOR AN EFFECTIVE PATIENT RETENTION IN OBSERVATIONAL STUDIES”. Journal of Population Therapeutics and Clinical Pharmacology 16, no. 1 (December 8, 2018). Accessed October 11, 2025. https://jptcp.com/index.php/jptcp/article/view/271.