They avoided immortal time bias by dividing a 12-year nationwide longitudinal cohort merged with the health checkup data into an “exposure ascertainment period” and an “outcome ascertainment period”. They used a daily defined dose system to determine the drug exposure. Read more . . .
Because aspirin can attenuate the incidence of various cancer types, researchers examined the link between aspirin use and incident pancreatic cancer in a large Asian cohort.