Identifying patients ‘outside the clinic’ can provide significant benefits for researchers and population health managers. Better understanding of patient cohorts can shed light on patient journeys, help optimize decisions around treatment choice and timing and inform the development of new therapies and intervention programs. Even without ‘in-clinic’ insight - the ability to directly interact with the patient, to confirm their membership in a cohort - we have plenty of population-level tools we can use to try to identify patients.