Chapter 8, Problem 128P

A study looked at the influence of retirement on the level of physical activity among people ages 45−64 in the Atherosclerosis Risk in Communities (ARIC) Study [18]. For this purpose a sport score from 1 (low physical activity) to 5 (high physical activity) and a leisure score from 1 (low physical activity) to 5 (high physical activity) were constructed. The main outcome measure was the sum of the sport and leisure scores [range from 2 (low physical activity) to 10 (high physical activity)]. These scores were ascertained at baseline (year 0) and at follow-up (year 6). A comparison was made between people who were still working at year 6 vs. those who were retired at year 6. The data in Table 8.31 were presented for African American women.

Table 8.31 Change in combined sport and leisure score for African American women in the ARIC Study (year 6 score – year 0 score)

[Hint: Assume that for d > 200, a t_d distribution is the same as an N(0,1) distribution]

Implement the test in Problem 8.127, and report a two-tailed p-value.

8.127 What test can be used to assess whether the underlying mean change score differs for retired women vs. working women?