Sample Testing of a New Drug for Pain Management


A new drug designed to control neuropathic pain needs to be tested using pain score measurements (on a scale of 0 – 10; 0 = no pain). Clinicians think that a standard deviation of 2 for the pain score would be a suitable value.  For the drug to be carried forward a minimum decrease in the pain score of 1 is needed.

(a) Suppose that the trial is designed to have 90% power to find a minimum treatment effect of 1 at a 5% significance level. What would be a suitable sample size?

(b) Suppose that the power is changed to 80%, what is a suitable sample size now?

(c) Suppose that the trial only recruited 300 patients, what would be the minimal treatment difference that could be detected with 80% power?

(d) What if the minimal treatment difference is changed to 2 (but the power remains at 80%), and that we want the patients allocated to the two arms in the ratio 2:1. What would be an appropriate sample size?


The question belongs to Statistics and it is about a proposed study for a new drug controlling neuropathic pain. A scale of measurement for pain management has been taken and to know if the drug works, the scale must come down by at least 1 point. The solution discusses the various questions about this study.

Total Word Count 187

Download Full Solution


  • HWA

    this is a very good website

  • HWA

    I have 50 questions for the same test your page is showing only 28

  • HWA

    hi can you please help or guide me to answer my assignments. thanks

  • HWA

    hi can anyone help or guide me to my assignments. thanks

  • HWA

  • HWA

    This solution is perfect ...thanks

  • HWA

    Hello Allison,I love the 2nd image that you did! I also, had never heard of SumoPaint, is something that I will have to exolpre a bit! I understand completely the 52 (or so) youtube videos that you probably watched. Sometimes they have what you want, sometimes they don't! However, it is always satisfying when you are able to produce something that you have taught yourself. Great job!Debra 0 likes

  • HWA

    Perfect bank of solution. 

  • HWA

    great !

  • HWA
    Paul Brandon-Fritzius

    thanks for the quick response. the solution looks good. :)

  • HWA
    tina Johnson

    thnx for the answer. it was perfect. just the way i wanted it. 

  • HWA

    works fine.