In a paper in the New England Journal of Medicine, Rodeheffer et al. (1983) asse

Question

In a paper in the New England Journal of Medicine, Rodeheffer et al. (1983) assessed the effect of a medication, nifedipine, on the number of painful attacks in patients with Raynaud's phenomenon. In this study, 15 patients were selected at random from a population of patients affected with this disease. They were randomly assigned to one of two treatment sequences: Placebo followed by Nifedipine, or Nifedipine followed by Placebo. The number of attacks during two week period on each "medication" was recorded A. Calculate a 95% confidence interval for the difference in the mean number of attacks in a two week period on placebo compared to treatment with nifedipine B. Calculate a 99% confidence interval for the difference in the mean number of attacks in a two week period on placebo compared to treatment with nifedipine

Explanation / Answer

for (n-1=14) degree of freedom and 95% CI, critical t =2.1448

hence margin of error =t*std error =2.1448*1.444 =3.097

hence confidence interval =mean +/- margin of error =0.770 ; 6.963

B)

for (n-1=14) degree of freedom and 99% CI, critical t =2.9768

hence margin of error =t*std error =2.9768*1.444 =4.298

hence confidence interval =mean +/- margin of error =-0.431 ; 8.165

S. No Placebo Nifedipine difference(d) 1 15 0 15 2 3 5 -2 3 14 6 8 4 6 0 6 5 12 2 10 6 6 1 5 7 3 2 1 8 22 30 -8 9 15 14 1 10 11 5 6 11 7 2 5 12 12 4 8 13 45 45 0 14 14 15 -1 15 35 31 4 mean 3.867 std deviaition 5.592 std error= std dev/(n)^(1/2) 1.444

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.