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Chapter 4: Problem 60

Suppose a doctor telephones those patients who are in the highest \(10 \%\) with regard to their recently recorded blood pressure and asks them to return for a clinical review. When she retakes their blood pressures, will those new blood pressures, as a group (that is, on average), tend to be higher than, lower than, or the same as the earlier blood pressures, and why?

Short Answer

Expert verified
On average, the new blood pressures recorded for these patients would tend to be lower than the initial readings due to the phenomenon of 'regression to the mean.'

Step by step solution

01

Understanding 'Regression to the Mean'

First, it is important to understand the concept of regression to the mean. This phenomenon is observed when individuals with extreme initial values on a certain variable are measured again. The second measurement will tend to be closer to the average than the initial extreme value.
02

Applying the Concept to the Exercise

The doctor has selected the patients who were in the highest 10\% with regard to their blood pressure levels, which points to extreme values. Therefore, when these patients are measured again, it is expected, according to regression to the mean, that their blood pressure levels will be closer to the average.
03

Conclusion

Based on the concept of regression to the mean, one can conclude that, as a group, the new blood pressure levels of the selected patients would tend to be lower than the earlier blood pressures when measured again.

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Most popular questions from this chapter

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