Investigators want to measure the incidence of root caries in older adults and see how it relates to xerostomia that is present at the start of the study. Which study design is most appropriate?

Explanations

• A cohort study follows people grouped by exposure over time, so it can measure incidence and establish that the exposure came before the outcome. A cross-sectional study measures prevalence at a single point in time and cannot give incidence.

  Source: Fletcher, Clinical Epidemiology: The Essentials — oneguy