An investigator uses the number of incident cases of tuberculosis over 5 years divided by the total person-time contributed by all study participants. This measure is BEST described as:

• A Cumulative incidence
• B Point prevalence
• C Period prevalence
• D Incidence density (hazard rate) ✓

Explanation

Incidence density (incidence rate or hazard rate) uses person-time in the denominator, accounting for variable follow-up durations. Cumulative incidence uses the initial at-risk population as the denominator and assumes a fixed period. Point prevalence is all cases at a single time point divided by total population. Using person-time denominator correctly handles competing risks and variable follow-up, making incidence density the most precise measure in cohort studies.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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