Epidemiology and pharmacoepidemiology frequently employ Real-World Data (RWD) from healthcare teams to inform research. These data sources usually include signs, symptoms, tests, and treatments, but may lack important information such as the patient's diet or adherence or quality of life. By harnessing digital tools a new fount of evidence, Patient (or Citizen/Person) Generated Health Data (PGHD), is becoming more readily available. This review focusses on the advantages and considerations in using PGHD for pharmacoepidemiological research. New and corroborative types of data can be collected directly from patients using digital devices, both passively and actively. Practical issues such as patient engagement, data linking, validation, and analysis are among important considerations in the use of PGHD. In our ever increasingly patient-centric world, PGHD incorporated into more traditional Real-Word data sources offers innovative opportunities to expand our understanding of the complex factors involved in health and the safety and effectiveness of disease treatments. Pharmacoepidemiologists have a unique role in realizing the potential of PGHD by ensuring that robust methodology, governance, and analytical techniques underpin its use to generate meaningful research results. K E Y W O R D S big data, data privacy, digital epidemiology, mobile apps, mobile health, patient generated health data, patient reported outcomes, pharmacoepidemiology, real world data, real world evidence, social media This article reflects the personal views of the authors and should not be construed to represent FDA's views or policies.

is an employee of Bayer Consumer Healthcare o Christelle Anquez-Traxler is an employee of AESGP, the Association of the European Self-Care Industry, which represents the manufacturers of nonprescription medicinal products, self-care medical devices and food supplements in Europe. The association is funded by member companies and national member associations' fees. o Matthew J Francis is an employee of The Procter & Gamble Company o Larry Ma is an employee of Johnson & Johnson o Denise Teotico Pohlhaus is an employee of GSK Consumer Healthcare o Sabine Landes is an employee of Sanofi-Aventis Germany Medical writing support was provided by Dr James Walmsley (Snakestick Ltd).