Question

A study is conducted to investigate the impact of depression on a patient’s ability to survive cardiac disease. They evaluated 477 participants for depression and followed for 4 years. There were 374 patients with no depression (ND) and 69 of them died. Out of 103 patients with minor or major depression (D), 28 died. Does it appear that the depressed (D) patients with cardiac disease are more likely to die than non-depressed (ND) patients with cardiac disease? Conduct a test of hypothesis at 5% level of significance. What is the p-value for the test? Alternate and null hypothesis? Test statistic?

Answer 1

We want to see whether the depressed (D) patients with cardiac disease are more likely to die than non-depressed (ND) patients with cardiac disease.

Therefore, the null and alternative hypotheses for this test are,

Using TI-83 plus calculator we get,

Test statistic is, z = 1.950

p-value = P(Z > 1.950) = 1 - P(Z < 1.950) = 1 - 0.9744 = 0.0256

=> p-value = 0.0256

Since, p-value = 0.0256 < 0.05, we should reject the null hypothesis.