TABLE 11-5
a Physician and President of a Tampa Health

question 64

Multiple Choice

TABLE 11-5
A physician and president of a Tampa Health Maintenance Organization (HMO) are attempting to show the benefits of managed health care to an insurance company. The physician believes that certain types of doctors are more cost-effective than others. One theory is that Primary Specialty is an important factor in measuring the cost-effectiveness of physicians. To investigate this, the president obtained independent random samples of 20 HMO physicians from each of 4 primary specialties - General Practice (GP) , Internal Medicine (IM) , Pediatrics (PED) , and Family Physicians (FP) - and recorded the total charges per member per month for each. A second factor which the president believes influences total charges per member per month is whether the doctor is a foreign or USA medical school graduate. The president theorizes that foreign graduates will have higher mean charges than USA graduates. To investigate this, the president also collected data on 20 foreign medical school graduates in each of the 4 primary specialty types described above. So information on charges for 40 doctors (20 foreign and 20 USA medical school graduates) was obtained for each of the 4 specialties. The results for the ANOVA are summarized in the following table.
$$\begin{array} { l r r r r r } \text { Source } & \text { df } & { \text { SS } } & \text { MS } & { F } & P R > F \\\hline \text { Specialty } & 3 & 22,855 & 7,618 & 60.94 & 0.0001 \\\text { Med school } & 1 & 105 & 105 & 0.84 & 0.6744 \\\text { Interaction } & 3 & 890 & 297 & 2.38 & 0.1348 \\\text { Error } & 152 & 18,950 & & & \\\text { Total } & 159 & 42,800 & & & \\\hline\end{array}$$
-Referring to Table 11-5, what was the total number of doctors included in the study?

• A) 160
• B) 159
• C) 20
• D) 40

---

Definitions:

Poisson Distribution

A distribution for predicting the probability of a given number of events occurring over a fixed interval of time or space.

Normal Distribution

A probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean.

Binomial Distribution

A probability distribution that summarizes the likelihood that a value will take one of two independent values under a given set of parameters or assumptions.

Random Variable

A factor that acquires numerical values due to chance occurrences.