A study was conducted in an area hospital to compare a new method of patient treatment during cardiac surgery with the current standard treatment. The new method of treatment, called FAST-tracking, was designed to speed patient recovery after surgery; one goal of the study was earlier discharge from the hospital. Fast-tracking made several modifications in patient care; among these was the use of steroids for fast-tracked patient

Investigators were interested in whether there is a real difference in the length of stay (LOS) for patients treated by the FAST-track method, compared to standard care.

The investigators also have a few other concerns about the data. While randomization of

patients to one of the two treatment groups can guard against investigator bias, it does not guarantee balance across all patient characteristics that may impact study outcomes, especially in a small study. Some of these characteristics can have real impact on the outcome of interest.

Older patients tend to have more complications with surgery, and consequently longer hospital stays. The investigators wish to know if there is a difference in age between the patients treated by fast-track and by standard care, since this could affect the hospital length of stay. Women who have cardiac surgery also tend to be sicker and have more complications than men having surgery. So there is concern that the treatment groups are balanced for age and for gender.

Another concern is whether there is a difference in weight gain between the two groups, since weight gain is a common side-effect of steroid treatment.

A small subset of the data recorded for the first 50 patients included in the study at one of the study sites are given below. Data available include:

• Subject ID (CASEID) – unique study patient identifier
• Treatment group FAST: 1=fast-track, 0=standard care
• SEX: 0=male, 1=female
• AGE in years
• length of stay (LOS) in days
• pre-operative weight (PREWT) in pounds
• post-operative weight (POSTWT) in pounds.

The data are available in the file fasttrk. MTW or fasttrk.jmp , in Minitab and JMP worksheet format. Note that missing data for a few subjects are indicated by an asterisk (*) in Minitab, or by a dot ( . ) in JMP. Data are also available in MS Excel format ( fasttrk.xls ) for easy import into other stat packages.

Define and conduct hypothesis tests to address the following research questions. Write a brief report that presents descriptive statistics on the variables of interest, addresses the research questions and presents your analysis and results. Your hypotheses, assumptions, results and conclusions should all be clearly stated in your report.

Research Questions:

1. Is there a difference in age between patients on the fast-track protocol, and those

receiving standard care?

2. Is the proportion of women included in the fast-track group the same as in the standard care group?

3. Is there a difference in weight gain between patients on the fast-track protocol and those receiving standard care?

4. Is the variability of length of stay similar among patients on the fast-track protocol, and

those receiving standard care?

5. Is there a difference in hospital length of stay among patients on the fast-track protocol, and those receiving standard care?

Price: $20.25

Solution: The downloadable solution consists of 10 pages, 1025 words and 14 charts.
Deliverable: Word Document