Question

The United States relies on reports published by the SEER surveillance team for many cancer related statistics. Suppose pancreatic cancer, the cancer with one of the worst survival rates, is reported to have a five year survival rate of only 6.0%. A cancer epidemiologist is working on a new observational study following patients with pancreatic cancer treated by a new chemotherapy treatment, and calculates that after 5 years of follow-up, 267 of the 321 patients have passed away due to the disease.

A) Conduct a formal test to determine if the 5 year survival rate seen by the cancer epidemiologist differs significantly from the SEER surveillance report. Use an alpha level of 0.05.

B) Construct a 95% confidence interval about your estimate, and interpret the interval.

Answer 1

(a) The hypothesis being tested is:

H0: p = 0.06

Ha: p ≠ 0.06

The p-value is 0.0000.

Since the p-value (0.0000) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that the 5-year survival rate seen by the cancer epidemiologist differs significantly from the SEER surveillance report.

(b) The 95% confidence interval about the estimate is between 0.791 and 0.873.

We are 95% confident that the true 5-year survival rate seen by the cancer epidemiologist is between 0.791 and 0.873.

Observed	Hypothesized
0.8318	0.06	p (as decimal)
267/321	19/321	p (as fraction)
267.	19.26	X
321	321	n
	0.0133	std. error
	58.22	z
	0.00E+00	p-value (two-tailed)
	0.791	confidence interval 95.% lower
	0.873	confidence interval 95.% upper
	0.041	margin of error