In a study to determine the incidence of a chronic disease, 150 people were examined at the end of a three-year period. twelve cases were found, giving a cumulative risk of 8%. fifty other members of the initial cohort could not be examined; 20 of these 50 could not be examined because they died. which source of bias may have affected the study?

The correct answer in the selection bias of this study is survival bias.

Explanation:

Selection bias is any bias found in the research regarding the choice of people or groups that will participate in the study. This is common when there is a distortion in the statistical analysis of the study due to failures in the sample of the chosen population.

Survivor bias or survival: when this bias is presented in the investigations, it is because some people who overcome the difficulties presented in the study are favored or because they lasted the corresponding time in the study, ignoring or diminishing the importance to people who did not overcome obstacles or who did not finish the study.

Therefore, survival bias occurs when conclusions of some participants are being made and ignoring the information that was provided for the study of the person who is no longer in the investigation.

When the selection bias is presented, it is often concluded that the conclusions of the study are not valid because of the fault that exists because of the bias. For example, in this case, where there is survival bias, and the investigation is of little validity due to the conclusions that were not taken into account of the deceased.

I hope this information can help you.

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.

answer; self_ disclosure;