Team 3Spring 2004

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Mountain View Community Hospital Database Project
Case
Brian Horn, Casey Reeder, Sheri Walls
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Who is MVCH?
Mountain View Community Hospital is a 150-bed,
not-for-profit, short-term, acute care general
hospital. The main concern of MVCH is to provide
high-quality health care for its surrounding
community while containing costs that have been
rising in accordance with national trends in
recent years. MVCH is in the process of
developing a high-level E-R diagram for the
hospital. Interviews with hospital staff and
administration have been conducted and our
development team of three persons has identified
the key entity types for the hospital and mapped
out the relationships on paper. Following are
questions that we asked, answers to those
questions, and findings from our meetings.
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Question 1
Why would MVCH want to use entity-relationship
modeling to understand its data requirements?
What other ways might the hospital want to model
its information requirements?
Mountain View Community Hospital would want to
use E-R modeling to understand its data
requirements because this approach will result in
capturing the business rules that are required to
maintain data integrity. The Hospital might also
want to model their requirements using the
object-oriented model shown in Chapter 5 of the
textbook.
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Exercise 2
Develop an E-R diagram for MVCH. State any
assumptions you had to make in developing the
diagram.
Please see E-R Diagram hand out.
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Exercise 4
Suppose the attribute bed number were a composite
attribute, composed of care center ID, room
number, and individual bed number. Redraw any
parts of your answer to Exercise 2 that would
have to change to handle this composite attribute.
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Question 4
No. MVCH is an instance of an entity type,
Hospital, of which there is only one instance.
Since this is the case, there is not a need to
model the Hospital entity type.
Is Mountain View Community Hospital itself an
entity type in a data model to represent its data
requirements?
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Exercise 3
The project description describes an entity type
called Item. Given your answer to project
exercise 2, will this entity type also be able
to represent in-room TVs as a billable item to
patients? Why or why not?
No. It would be difficult to bill for
television. MVCH would have to be setup on some
type of pay-per-view program. The Item entity
type has made provision for the billing with the
Unit-Cost attribute, but makes no provision for
neither a pay-per-view or unit-cost-per-day-to-vie
w system for the television.
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Exercise 5
Consider your new E-R diagram for Mountain View
Community Hospital after changing your answer to
Project Exercise 2 to handle the situation in
Project Exercise 4. Now, additionally assume
that a care center contains many rooms, and each
room may contain items that are billed to
patients assigned to that room. Redraw your E-R
diagram to accommodate this new assumption.
Please see second E-R Diagram handout.
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Question 2
Do there appear to be any weak entities in the
description of the Mountain View Community
Hospital data requirements? If so, what are they?
There are no obvious weak entities. TREATMENT is
the most likely candidate for the weak entity.
However, TREATMENT has its own identifier
(Treatment_ID, a composite attribute). Therefore,
we assume that this entity has an
independentexistence.
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Question 3
What is the significance in developing an E-R
diagram for MVCH to the third entry in the list
on page 125, which states that some patients are
assigned to a bed, but outpatients are not
assigned to a bed?
At this point in our learning of E-R diagramming,
we show the relationship (called Is_assigned)
between PATIENT and BED as an optional one
relationship.
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Exercise 1
Study the project description very closely. What
other questions would you like to ask in order to
better understand the data requirements at MVCH?

• Some other questions that could be helpful are
• Should we model pharmaceutical items separately
  from ITEM, since such items are prescribed by a
  physician for a patient?
• Is there a need to maintain a historical record
  of a patients relationship with the hospital? If
  so, how can this be modeled in the E-R diagram?
• Need we model the various subtypes of EMPLOYEE
  (nurses, staff, physicians)?
• Is there a need to model the relationship with
  other persons such as volunteers and donors?

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Exercise 6
Does your answer to Exercise 2 allow more than
one physician to perform a treatment on a patient
at the same time? If not, redraw your answer to
accommodate this situation. Make any additional
assumptions you consider necessary in order to
represent this situation.
Yes. Any combination of patient and treatment has
multiple physicians who perform that treatment.
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Exercise 7
Does your answer to Exercise 2 allow the same
treatment to be performed more than once on the
same patient by the same physician? If not,
redraw to accommodate this situation.
Yes. The model records the date, time, and
results for each treatment occurrence performed
by a physician on behalf of a patient.
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Brians Question

• In considering the rising cost of health care
  nationally, how could MVCH reduce the cost of
  health care to their patients?

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Brians Answer
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Caseys Question
How can MVCH maintain quality health care
services, in years that their incoming revenue
does not cover it's payroll budget, since it is
a  nonprofit organization?
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Caseys Answer
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Sheris Question

• This installment of the MVCH cases illustrates an
  instance where an entity may at the same time be
  another entity (Employee is also Charge Nurse).
• What other entities may also be concurrent and
  how would this be shown in an E-R diagram?

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Sheris Answer
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Conclusion
By diagramming and designing an E-R model, MVCH
has identified a number of ways to cut their
costs, to pass health-care savings to their
patients, streamline the flow of data, and
consolidate the management of their facility.