DATABASE CASE STUDY:
The Puget Sound Health Clinic
CSE100/INFO
100
Fluency
with Information Technology
Winter 2005
This
exercise provides a review of database technology and relational database
design. While learning the concepts
behind database design is helpful, one can only plan on mastering those
concepts by working through an actual project.
This mini-project is intended to improve your understanding of databases
and to provide an opportunity to study how the information system of an
organization is created to serve its specific needs. You will not implement the full system.
The eventual goal is to build the database application for
an imaginary regional health clinic to be called the Puget Sound Health Clinic
(PSHC). The clinic provides a variety of services and referrals, but this
assignment will be limited to the clinic's lab testing activities. The clinic
performs drug testing as well as testing for a variety of diseases: HIV, AIDS,
Hepatitis B, etc. An important aspect of
the database system is to assure privacy for the clients. A receptionist and
several health professionals staff the clinic.
The database system is intended to support their daily testing
activities.
Understanding
what things (items, people, events, etc) are important to an organization and
need to be tracked is the first step in any database system design. An
important first step is to identify how all of those things relate to each
other. By exploring how an organization
works and how information flows through it, you can identify those items most
important to the system.
In a real world design process, the database developer or
team spends many hours interviewing the system users and tracking organization
flow in order to identify the many items, events, actions and people to be
tracked. In these interviews a model of
the system will be developed. This
section is intended to replace many of those interviews.
This database is intended to support the processing of
clients who come to the clinic to have a test performed. During their visit they will give personal
information, be seen by a health professional and provide one or more fluid
specimens for testing. The actual tests
are not performed at the PSHC, but rather are performed at one or more labs in
Seattle. This means that the specimens
must be sent out; when they are returned the client is notified. It is assumed that the PSHC is a public
health clinic, the testing is free and its employees are volunteers.
Look at the flow of information through the clinic as a
guide to the design.
Arrival:
When a client arrives, the receptionist interviews him or
her to gather a small amount of personal data that is entered into the client’s
record. If the client has visited the
PSHC before, the receptionist simply verifies the information in the existing
record. The receptionist is then responsible for scheduling the client with one
of the health professionals. All
appointments are for the current day (this is a walk-in clinic) and are set up
on a first come, first serve basis. Any
emergency cases would immediately be diverted to the local emergency room and
not dealt with in the clinic.
Meeting
With the Health Professional:
After the client has waited for the health professional to
be free, the health professional interviews the patient to find out a brief
medical history and the type of test(s) sought.
The health professional fills out a form that is a record of the clinic
visit and the discussion. The form has
space for “chart” information as well as check boxes for the tests to be given,
including an “exceptional” situation.
If tests are ordered by the health professional (i.e. one
or more boxes have been checked) then a specimen (urine, blood, etc.) will be
collected from the client to be sent to the lab. A label must be generated to
attach to the sample. The label must include the pertinent information about
the test and the person requesting it.
To assure privacy a tracking number is used whenever a client must be
identified outside the clinic. The
number is not randomly generated, but neither is it easily identifiable with a
particular client.
Lab
Manifest:
Each day the lab test samples will be gathered together. An
employee compares all the specimens against a computer generated "lab
manifest" listing all of the requested tests by tracking number. After
making sure that all specimens are accounted for, each set of test specimens is
then grouped (Aids, HepB, etc.). The same employee will print each individual
test manifest, check that all specimens exactly match, and ship them to the
appropriate lab with that paper manifest (e.g. Aids). An electronic version of the manifest may
also be sent to the lab.
Results
Returned:
The lab will return the manifest. The results of each test
will be filled in. The outcomes are: positive, negative, failed (must be
repeated), inconclusive, and exceptional.
When the results of all tests requested on a particular visit are available,
a letter to the patient is generated. In the case that the test failed, the
client is encouraged to return to provide another specimen, which will produce
a separate visit transaction. Once the
letter is generated, the visit is "closed". To assist the clinic’s administration and
public health officials, summary statistics are generated each quarter. These
include the number of clients visiting, and summaries of the outcomes, i.e.
number of positives, negatives, etc. in each category.
Analyzing all of the previous description will reveal those
entities (items, people, actions and events) most important to the clinic that
should be tracked.
1. What categories of people are mentioned?
2. What are the important actions and events that take place?
3. What physical items are involved?
4. Which people are involved in which actions and items?
5. What information does a database system need to maintain in
order for the people to accomplish their tasks effectively? Think about this only in the most general
terms. Specifics will be filled in
shortly.
The actions and processes described above give us an idea
of the items, people, events and their relationships to each other that need to
be tracked. Once identified, they become
components of the system. These and
additional components are necessary to support the clinic’s daily operation and
should be included in the basic database design.
From the Arrival description, it is evident that tracking
Client information is very important. It
seem that the database will need to contain
In order to help the receptionist to enter information
into this table, a form many be appropriate. The form should be attractive, be
embellished with the lab’s name and look suitably professional. Once new client information has been added to
the table through use of the form, the receptionist will schedule the client
with a health professional. The
scheduling of a visit between a doctor and patient will require opening an
additional form that can start a visit record with the appropriate
information. The database system should
have a mechanism for doing so.
From the Meeting description, it seems that certain
important information about each volunteer doctor, nurse, etc. should be
maintained:
·
Clinic Volunteer ID (specific to the Health Clinic)
·
First and Last Name
·
Degree (RN, MD, etc)
·
Contact information
·
State health license number
·
Social Security Number
·
Notes (days available to volunteer, etc)
There should be a form for entering data for this table
that is attractive and consistent in design with the other forms.
Also from the Meeting description is the fact that each
event of a client seeing a health professional should be recorded. Relevant data would include:
·
The ID for the Visit
·
The client’s ID from the Client table
·
The Health Professional’s ID from the Health
Professional table
·
Tests requested (need a field for each test)
·
Test outcome data (need a field for each test
outcome)
·
A tracking number
·
Recent Medical History (since last visit)
·
Current Symptoms
·
Remarks/Notes
The tracking number is not necessarily the unique record
ID for a table. Instead it is a
multi-digit number used to identify the specimens. This number preserves the
anonymity of the client while the specimens and tests are being processed
outside the clinic. One tracking number is associated with each visit of a
client, and so if more than one test is ordered on a single visit, the same
tracking number will be used on each. There should be a field to record the
outcome of each test, once it is returned.
The people involved in the application interact with one
another and with the database.
Frequently, the database interactions require a form or a report.
The scheduling of a visit between a doctor and patient by
the receptionist will require use of a form that can start a visit record with
the appropriate client and doctor information. The receptionist needs to view different
pieces of data than the health professional.
The Reception desk is only concerned that:
·
The Visit be uniquely identified from any other
that day
·
The proper client identification number is noted
·
The proper health professional identification number
is noted
For the interactions between the client and the health
professional, another form is needed for entering the additional data:
·
The Visit identification number
·
The date of the visit (to verify the record is not
from another time)
·
The client’s name: first and last
·
The health professional’s name: first and last
·
Health professional certification (RN, MD, etc)
·
A way to show if a test should be ordered
·
The tracking number
·
Notes fields (symptoms, history, remarks, etc.)
For each test requested, a label must be printed to be
affixed to the specimen. This label includes the clinic’s name, address and
phone number, the date and the tracking number.
From the Lab Manifest description, it is necessary to
create a complete manifest of all tests to be sent to the labs with the
specimens that:
·
Lists the tracking numbers for all requested tests
·
Shows the checked boxes for each test as
confirmation that it was ordered.
From the complete manifest each individual test manifest
will be created to send to the various labs. Though a paper copy is sent with
the specimens, an electronic copy should also be sent to the labs showing the
tracking numbers requesting that test.
This way the clinic and the lab can each run a check of specimens
against the test manifest.
The Results Returned description explains that the lab
will return the manifest for each test set submitted to it. The test manifests
will come to the receptionist who will enter the results fields each test. There will only be one of 4 possible results
listed (positive, negative, etc). This requires a form for easy data entry by
the receptionist. The information that
the receptionist sees, however, should be limited to the tracking number and
the outcome field for entering the results.
From the Notification description, there must be a letter
generated to the client once all of the tests from a visit have been received.
The letter reports the results of each test. If any test’s outcome is
"fail" or "inconclusive", a paragraph is inserted
recommending that the client return to the lab for a retest. Notice that since
a single letter is generated for (possibly) multiple tests, sorting the merged
Lab Manifest table on the tracking number field will result in grouping
together the tests of one visit. Once the letter and a mailing label have been
generated, the record can be closed and moved from the Visit table to the Visit
Archive table. Similarly, all returned Lab Manifest table records that have
been reported should also be moved to the Lab Manifest Archive table. A summary statistics report is generated from
the Lab Manifest Archive table. The statistics are (a) the number of visits,
(b) the number of tests, (c) the numbers of tests of each type and the
outcomes. In addition, there should be a summary of the number of visits by
month for each month in the quarter.
Finally, because of privacy practices in the medical field
and possibly state laws, the database must be password protected. Further, it
should contain an "auto close" facility that exits the database when
no activity has occurred for a while. This will protect unintended access when
the health professional leaves the computer.
Based on your understanding of the problem,
and the analysis above, record your answers to the questions below. You should use your own paper, and expect
some of the answers to be rather long.
Your answers in this section will count more than the answers in the
first part.
1. Who are the users of the database?
2. What are the entities of the database?
3. What tables should be defined? Give their names and a one-sentence
description of each.
4. For each table, give its schema
5. What forms are needed?
Give each one a name and a one-sentence description.
6. For each form, state who its users are, and which
tables the data comes from.