Final answer:
Cohort studies' limitations include being time-consuming, requiring significant financial investment, and dealing with high participant attrition rates that can affect the sample's representation of the larger population.
Step-by-step explanation:
The question pertains to the limitations/disadvantages of cohort studies in the context of medical research. Cohort studies have several disadvantages that researchers must consider. Firstly, they can be time-consuming, often requiring many years to observe outcomes, which delays the availability of results. Secondly, cohort studies demand a significant financial investment, making them difficult to maintain over long periods. Finally, high attrition rates due to participants dropping out can skew the representativeness of the sample over time, and continual effort is required to ensure the sample remains representative of the larger population. Adjustments may be necessary to account for any changes in the population being studied.