MATH 160 Cuyamaca College Clinical Depression Statistics Discussion

Clinical depression is a recurrent illness requiring treatment andoften hospitalization. Nearly 50% of people who have an episode of majordepression will have a recurrence within 2-3 years. Being able toprevent the recurrence of depression in people who are at risk for thedisease would go a long way to alleviate the pain and suffering ofpatients.

During the 1980’s the federal government, through theNational Institutes of Health (NIH), sponsored a large clinical trial toevaluate two drugs for depression. There were 3 treatment groups.Patients received either Imipramine (Imip), Lithium (Li), or a Placebo(Pl). Researchers randomly assigned patients to one of the 3 treatmentgroups and followed them for 2-4 years to track any recurrences ofdepression.
(Prien et al., Archives of General Psychiatry, 1984).

Variables

• Hospt: Which hospital the patient was from: Labeled 1, 2, 3, 5 or 6
• Treat: 0=Lithium; 1=Imipramine; 2=Placebo
• Outcome: 0=Success 1=Failure (recurrence of depression)
• Time: Number of weeks until a recurrence (if outcome=1) or until study ended (if outcome=0)
• AcuteT: How long the patient was depressed before the start of the current study, measured in days
• Age: Age in years
• Gender: 1=Female 2=Male

Data

If you have not done so already, download the depression datafile (as always, if a login box opens, just close it and then download the file). Then upload the file in StatCrunch.

Prompt

We will analyze the data to answer the 1st research question: Which of the drugs (if either) was more successful in preventing the recurrence of depression relative to the placebo?

In the previous lab-preparation activity, we determined that we willanalyze the data using a two-way table and conditional percentages.

1. Use StatCrunch to produce a two-way contingency table. (directions)
   Copy the table in your StatCrunch output window and paste it in your initial discussion post. (directions)
   After you paste the content of the your StatCrunch output window into your discussion post, keep the table titled Contingency table results: and delete the Chi-Square results: table.
2. Analyze the data in your two-way table by finding appropriateconditional percentages. Write each conditional percentage as a ratio(e.g. 25 out of 40) and as a percentage (e.g. 25/40 = 62.5%). Then writea sentence that explains the meaning of the percentage in the contextof the research question.
3. Draw a conclusion. Based on this study, which drug was the mosteffective in preventing the recurrence of depression? Support yourconclusion using conditional percentages.

List of StatCrunch Directions

Each link will open in a new window. To return to thisdiscussion, either close the new tab or select the tab for thisdiscussion.

• Create Your Stats-Class Folder in Canvas (You only need to do this once.)
• Purchase StatCrunch (You only need to do this once.)
• Open StatCrunch
• Download Excel Data File
• Upload Excel Data File to StatCrunch
• Download StatCrunch Output Window (no screenshots; please use these directions)
• Upload Files into Your Stat-Class Folder in Canvas
• Embed Pictures in a Discussion Post (no attachments; please use these directions)
• Create a Two-way Contingency Table with Data
• Copy & Paste a StatCrunch Table

Here is a PDF document with all StatCrunch directions (Links to an external site.).