In 2020, investigators were interested in evaluating the relationship between cholesterol levels and stroke. Using BRFSS data, they identified a random sample of 2,000 participants in South Carolina, 1,000 of these participants had experienced stroke, and the remaining 1,000 did not. The investigators identified 750 participants with stroke had "high" cholesterol. The investigators also determined that 650 participants without stroke had "low" cholesterol. What is the main limitation of this study design? The study only includes cases. There is no comparison group. The unit of observation is the group; so results cannot be assumed to apply to individuals. This type of study is expensive to carry out, and non-compliance of study participants must be dealt with in the anatysis. The exposure and outcome were measured on study participants at the same time; therefore, temporality cannot be established..

1. In 2020, investigators were interested in evaluating the relationship between cholesterol levels
and stroke. Using BRFSS data, they identified a random sample of 2,000 participants in South
Carolina, 1,000 of these participants had experienced stroke, and the remaining 1,000 did not.
The investigators identified 750 participants with stroke had "high" cholesterol. The investigators
also determined that 650 participants without stroke had "low" cholesterol. What is the main
limitation of this study design? The study only includes cases. There is no comparison group.
The unit of observation is the group; so results cannot be assumed to apply to individuals. This
type of study is expensive to carry out, and non-compliance of study participants must be dealt
with in the anatysis. The exposure and outcome were measured on study participants at the same
time; therefore, temporality cannot be established.