HAP 709: Healthcare Databases

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HAP 709 Healthcare Databases

• Introduction to Database Structures
• Janusz Wojtusiak, Ph.D.
• Fall 2010
• Based on slides by
• Farrokh Alemi, Ph.D.
• Francesco Loaiza, Ph.D. J.D.

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What is a database?

• Is an Excel table with students grades a
  database?
• Is your notebook a database?
• Is a phonebook a database?
• Is the GMU schedule of classes a database?
• Is a medical record of a patient a database?
• Is a list of nurses working in a hospital a
  database?

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What is database?

• Database is a collection of data with defined
  structure and purpose.
• Wikipedia A Database is a structured collection
  of data which is managed to meet the needs of a
  community of users.
• Wordnet Database is an organized body of related
  information.

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What is computer database?

• Computer database is a database stored in a
  computer.
• It is usually managed by special software called
  Database Management System (DBMS).
• There are many DBMS systems available
• Access, Oracle, MUMPS, dBASE, portgress, sql
  server, mysql, db2,

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Objectives of this lecture

• Learn about flat, hierarchical, relational, and
  object-oriented databases
• Learn about information-less databases

If checking an information item takes a fraction
of a second, why is it that we search through
billions of information items in a fraction of
a second?
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Types of Data Structures

• Flat data
• Hierarchical data
• Relational data
• Object-oriented data

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Flat Models
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Flat Data

• How do we keep two addresses for the same
  student?
• What if there are five addresses?

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Flat Data

• Advantages
• Most software include free access to flat data
  files.  For a small number of cases, flat
  databases do a reasonably fast job.
• Most analytical software use flat data.
• Disadvantages
• Flat databases waste computer storage by
  requiring it to keep information on items that
  logically cannot be available
• It is almost impossible to design flat models for
  things with varying numbers of properties
• Flat databases are not conducive to complicated
  search queries

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Hierarchical models

• Data models in which the relationship between
  higher and lower items are inherited.

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Example of Hierarchal Model
Person
Patient
Employee
Contractor
ICU
Admin
Clinical
Clinic
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Advantages of Hierarchical Models

• Advantages
• Operations on parents save time and affect all
  children.
• Disadvantages
• Many relationships are not hierarchical

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Relational Databases
In a relational data base, one stores a record
with related fields as data.

• In a relational database, tables do not need to
  be of the same size

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Example
Table for "Students grades" 
Table for "Students' contact information"

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Advantages of Relational Databases

• Data can be examined from many different
  perspectives. 
• No need to enter missing information for
  variables that are not logically possible.
• Easy to modify because adding new concepts
  involves adding new Tables, not altering old ones.

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Object-oriented data models

• Data are organized in the form of objects that
  represent real world entities. Each objects have
  its properties, that can be regular values or
  other objects.

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Advantages of Object-oriented models

• Advantages
• High efficiency
• Use of the actual real life entities as objects
• Integration with object-oriented programming
  languages (C, Java, C )
• Disadvantages
• Lack of one good standard

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Distributed data models

• Data are kept in different settings and on
  different computers. Distributed databases need
  not only addresses for where the data are but
  also need an audit trail
• HAP 720

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Advantages and Disadvantages of Distributed
Databases

• Security of these databases are difficult to
  maintain.
• Many agreements must be made ahead of time.
• Data loss is limited to nodes affected.
• Decentralized databases are more flexible and
  allow different units to update and maintain
  their own data. 
• Variation in quality of data

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Data-less Information Systems

• Distributed Databases without data until need
  arises, less problems with privacy of patients
• Sometimes called federated databases.

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 Components of a Data-less System

• Decoder  
• Communicator  
• Analysis

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Advantages of the Data-less Information Systems

• The system is substantially less expensive than
  centralized registries as it requires no new
  equipment and little personnel. 
• The system does not require duplication of data
  in different databases.

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Inductive Databases

• Researchers investigate databases that can answer
  questions about things which are not explicitly
  in that databases. They use artificial
  intelligence to give plausible answers.

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Take Home Lesson

• Structure makes it possible to process and
  analyze large amount of data