Question: Suppose a meta-analysis on the risks of drinking coffee included 100,000 participants of all ages across 80 studies. One of the conclusions was that a confidence interval for the relative risk of heart attack for women over 70 who drank coffee, compared with those who didn't, was 0.90 to 1.30. The researchers concluded that coffee does not present a problem for women over 70. Explain why their conclusion is not justified.