OTHER NAMES:

INCIDENCE STUDY (AS INCIDENCE CAN BE MEASURED DIRECTLY)

FOLLOW UP STUDY (AS CONTINUOUS FOLLOW UP IS ESSENTIAL)

PROSPECTIVE STUDY (AS THE DIRECTION OF THE STUDY IS FORWARD-LOOKING)

Cohort studies are of this design. These studies, though yield incidence directly, are time consuming and expensive when compared to cross- sectional onetime studies.

It should be remembered that the follow up given during the disease management e.g. follow up of patients with tuberculosis during treatment, is not to be confused with these longitudinal studies.