Epidemiology- Longitudinal Exam 2023 Solved 100%

What does a longitudinal study involve? - ANSWER-repeated observations of the same items over long periods of time (e.g., months, years, decades) What are some longitudinal study designs? - ANSWER-Observational: Cohort study- prospective or retrospective Experimental studies: a. RCT b. Quasi-experimenta c. Natural experiment Apriori hypothesis - ANSWER-A hypothesis we create before the study Cohort studies - ANSWER-1. OBSERVATIONAL- exposure is not assigned by researcher 2. ANALYTICAL- tests an a priori hypothesis comparing risk in exposed vs unexposed individuals -Exposure can be almost anything, including characteristics such as age, gender or race Types of Cohort Studies: Prospective Cohort Study - ANSWER--Cohort recruitment and baseline assessment for exposure occur in present (real-time, in person) --Exposure status determined in present -Participants followed forward into the future to determine disease risk Types of Cohort Studies: Retrospective Cohort Study - ANSWER--Cohort recruitment and baseline assessment for exposure gathered USING RECORDS FROM THE PAST. -Cohort is defined for a time period in the past -Exposure at that time in the past is determined using records -Participants followed FORWARD in time to determine disease outcome in the more recent past, present, or future T or F. Prospective and retrospective studies are both followed forward in time. - ANSWER-True. This is on the test! Retrospective Cohort Studies - ANSWER--Identify cohort and past exposure status from records collected IN THE PAST -Follow participants FORWARD in time for outcome up to: -Some point in the more recent past and determine outcome using records also collected in the past (retrospective). -Present (ambidirectional).