Clinical depression is the most common mental illness in the United States, affecting 19 million adults each year (Source:NIMH,1999). Nearly 50% of individuals who experience a major episode will have a recurrence within 2-3 years. Researchers are interested in comparing therapeutic solutions that could delay or reduce the incidence of recurrence.

In a study conducted by the National Institutes of Health, 109 clinically depressed patients were separated into three groups, and each group was given one of two active drugs (imipramine or lithium) or no drug at all. For each patient, the dataset contains the treatment used, the outcome of the treatment, and several other interesting characteristics.

Below is a summary of the variables in our dataset. Use this to answer the questions below.

Hospt: The patient's hospital, represented by a code for each of the 5 hospitals 1, 2, 3, 4, 5, or 6

Treat: The treatment received by the patient (Lithium, Imipramine, or Placebo)

Outcome: Whether or not a recurrence occurred during the patient's treatment (Recurrence or No Recurrence)

Time: Either the time in days till the first recurrence, or if a recurrence did not occur, the length in days of the patient's participation in the study.

AcuteT: The time in days that the patient was depressed prior to the study.

Age: The age of the patient in years, when the patient entered the study.

Gender: The patient's gender (1 = Female, 2 = Male)

Examine each of the variables in the dataset as well as their descriptions above.

Which of the following variables is quantitative?

a. Hospt
b. Time
c. Gender
d. Time.