Transcript Diapositiva 1

HOW TO BUILD A CLINICAL DATABASE
Alberto Briganti
Urological Research Institute
Vita Salute San Raffaele University
Dept. of Urology, Milan, Italy
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DATABASE DEFINITION
“A systematized collection of data that can be
accessed immediately and manipulated by a
data-processing system for aspecific purpose”
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DATABASE DESIGN CONSIDERATIONS
The main design goal for all databases is
to store the data accurately
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DATABASE DESIGN CONSIDERATIONS
A good database design balances various needs
and limitations:
• Clarity, ease, and speed of data entry
• Efficient creation of analysis data sets
• Formats of data transfer files
• Database application software requirements
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ENTERING DATA
• Selecting a method to transcribe the data
• Determining how closely the data must match
with the case report forms
• Making edits and
“jeopardizing” quality
changing
data
without
• Quality control of the entire process
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DATABASE STRUCTURE
FIELD
RECORD
VALUE
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CLINICAL DATABASE
Included data:
• Numeric values (i.e.: age, PSA, time of surgery, …)
• Text (i.e.: drugs, co-morbidities, …)
• Date (i.e.: date of birth, date of surgery, …)
• Complex objects (i.e.: images, …)
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INCLUDED DATA
NUMBER
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INCLUDED DATA
TEXT
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INCLUDED DATA
DATE
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TYPES OF VARIABLES
• Continuous (quantitative) variables: measured as a
number for which arithmetic operations make sense
(height, age, PSA, …)
• Categorical (qualitative) variables: has two or more
categories. Categorical values have not numerical
meaning.
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CATEGORICAL VARIABLES
• Nominal variables: have two or more categories but do not have
an intrinsic order
• 1: Adenocarcinoma
• 2: BPH
• Dichotumous variables: have only two categories or levels
• 1: Male
• 2: female
• Ordinal variables: have two or more categories just like nominal
variables and the categories can also be ordered or ranked
• 1: PSA<4 ng/ml
• 2: PSA between 4 and 10 ng/ml
• 3: PSA >10 10 ng/ml
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TYPES OF VARIABLES
CONTINUOUS
VARIABLE
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TYPES OF VARIABLES
CATEGORICAL
VARIABLES
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QUERY
• To search, to question, to find
• Question to the database
department(s) is Joe in?)
(i.e.:
“Which
• Usually constructed using SQL (structured query
language)
• The answer to any query will be a relation
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QUERY TYPES
• Select query: simple data retrival
• Action query: additional operations on the
data (insertion, updating or deletion)
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CLINICAL DATA ACQUISITION
• Prospective data acquisition: data of a cohort of
subjects are prospectively collected from a certain
moment to test a defined hypothesis
• Retrospective
data
acquisition:
data
are
retrospectively collected
to investigate the
association between risk/protection factors and
clinical outcome
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CLINICAL DATA ACQUISITION
• Pre-operatory questionnaires
• Clinical records
• Follow-up visits
• Phone interviews
• Post-operatory questionnaires
• Register office anagraphic data
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WRITTEN CONSENT
• Is necessary for any kind of clinical data
management
• For acquisition and analysis of their data, patients
are asked to fill a specific written consent
• One day before surgery, medical providers
explain the importance of data acquisition
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QUESTIONNAIRES
• List of questions for the purpose of gathering
informations from the respondents
• Two main goals:
• Obtain any information
purposes of the survey
relevant
to
the
• Collect the information with maximal realibility
and validity
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VALIDATED QUESTIONNAIRES
A validated questionnaire means that it has
undergone a validation procedure to show that it
accurately measures what it aims to do, regardless
of who responds, when they respond, and to whom
they respond
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VALIDATED QUESTIONNAIRES
Advantages of validated questionnaires:
• Reduce bias by detecting ambiguities and
misinterpretations
• Aim at high degree of “specific objectivity”
• Collect better quality data
• Offer the opportunity to compare results
between different studies
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VALIDATED QUESTIONNAIRES
INTERNATIONAL PROSTATIC SYMPTOM SCORE
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VALIDATED QUESTIONNAIRES
INTERNATIONAL INDEX OF ERECTILE FUNCTION
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CLINICAL RECORD
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CLINICAL RECORD
• Patient hystory
• Type of surgery
• Surgical complications
• Hystological findings
• Duration of hospital stay
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FOLLOW-UP VISITS
• Every 3 months during the first year after surgery
and every 6 months thereafter
• Questionnaire administration (i.e.: IIEF, ICIQ, IPSS)
• Imaging and laboratory data acquisition
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REGISTER OFFICE ANAGRAPHIC DATA
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hSR PROSTATE CANCER DATABASE
• November 2001: hSR
created using excel files
Prostate
Cancer database
• Clinical and pathological data prospectively collected
from 2002
• Data of 1200 patients treated with radical prostatectomy
before 2002 retrospectively collected
• 2004: due to the large amount of data included in PCa
database, a FileMaker Pro database was created
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hSR PROSTATE CANCER DATABASE
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hSR PROSTATE CANCER DATABASE
• 6000 patients treated with open RRP
• 850 patients
prostatectomy
treated
with
robotic-assisted
laparoscopic
• Clinical and pathological data prospectively collected from 2001
• The number of RP has increased over time and today we
perform 600 RP every year
• In 2011 50% of RP were performed with a robotic-assisted
laparoscopic approach
• Complete preoperative data from 2050 patients
HOW TO BUILD A CLINICAL DATA-BASE
PERSONAL SUGGESTIONS…
1. As beginners, please makes it as easy a possible
2. Try to be prospective
3. If retrospective careful should be taken to avoid selection biases
4. Excel file is easy, but be careful…
5. Avoid text as much as possible (numeric conversion)
6. However, try to limit the number of categories within each variable
7. Try to sub-divide the data-base into different , connected sub-structured
8. Do not include too many variables…
9. Use standardized assessments (i.e. TNM) and questionnaires
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HOW TO BUILD A CLINICAL DATA-BASE
PERSONAL SUGGESTIONS…
1. Do not use “subjective variables” (unless to be tested in trials)
2. Every time dependent variables should have the time to event available
3. Restrict your queries
4. Copy patient charts
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