A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma

A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma

3. A clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma.  Two hundred participants are enrolled in the study and randomized to receive either the experimental medication or placebo.  The primary outcome is self-reported reduction of symptoms.  The data are recorded as follows.

Change in Symptoms

Treatment Much Worse Worse No change Better Much Better

Experimental 10 17 35 28 10

Placebo 12 25 42 12 9

Is there a difference in change in symptoms by treatment group?  Run the appropriate test at a 5% level of significance.

4. The following data was collected in a clinical trial evaluating a new medication designed to improve wound healing in trauma patients.  The new compound is compared against a placebo.  After treatment for 10 days with the new compound or placebo the extent of wound healing is measured and the data are shown below.

Percent Wound Healing

Treatment 0-25% 26-50% 51-75% 76-100%

New psoriasis medication (n=125) 15 37 32 41

Placebo (n=125) 36 45 34 10

Is there a difference in the extent of wound healing by treatment?  (Hint:  Are treatment and the percent wound healing independent?)  Run the appropriate test at a 5% level of significance.