The document discusses using lag variables in Oracle Clinical procedures. It provides an example of using lags to check that episodes of nausea are recorded between assessments of nausea. The example models the assessment and episode forms, writes a validation procedure using lags, and explains how to structure the procedure and compare dates/times in Oracle Clinical. The presenter has over 15 years of experience implementing Oracle Clinical.

1. OHSUG Annual Conference
October 16-19, 2011
Toronto, Ontario Canada
Using Lag Variables in
Oracle Clinical
Procedures
Steven Rifkin
Copyright © 2011 BioPharm Systems, Inc

2. Topics
• Setting up Lags in a procedure
• Lag Example
– Description of the forms and required edit check
– Modeling the Forms
– Writing the validation procedure
– Structure of the procedure
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Lags in Oracle Clinical
Lags in Procedures

3. Lags …
• Lags retrieve previous instances of the
response to a question
• Lag Aggregates summarize the previous
instances
• Can specify how many previous responses
are remembered (depth) and whether to
count null responses
• Defined on the Procedure Questions Screen
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Lags in Procedures

4. Lags …
Specify Lag Depth to
Define if the aggregate of
create Lags
the Lags are available
Checks means to include
nulls in the lag count
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Lags in Procedures

5. Lags
• Lags Variables are referenced
<alias>$<question name>$Ln for value
<alias>$<question name>$In for response_id
<alias>$<question name>$Tn for entry_ts
• Aggregate Lag Values are referenced
<alias>$<question name>$fc
where fc is AV, MN, MX, SM, or CT
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Lags in Procedures

6. Lag Example …
V_NAUSEA_CHECK
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Lags in Procedures

7. Lag Example …
Make as Assessment of Nausea at scheduled times
and respond ‘Yes’ if there was an Episode of Nausea
since the previous Assessment
If ‘YES’ record the episode(s) on
the Episodes of Nausea Form
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Lags in Procedures

8. Lag Example
Record Date and Time of each Episode of Nausea and
the intensity of the episode
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Lags in Procedures

9. Lag Edit Check Description …
Check that if the Assessment of Nausea
form has been marked YES for an
assessment period
Then there is at least one episode of
Nausea indicated on the Episode of Nausea
form in the period since the last
assessment was performed.
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Lags in Procedures

10. Lag Edit Check Description …
Assessment
Form
02-01-02 07:05
02-01-02 08:04 Nausea
Episode Form
OK! 02-01-02 07:35
02-01-02 07:55
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Lags in Procedures

11. Lag Edit Check Description
Assessment
Form
02-01-02 07:05
02-01-02 08:04 Nausea
Episode Form
Not OK!
No Nausea Episode
reported between
07:05 and 08:04
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Lags in Procedures

12. DCM Modeling
• Both forms modeled with Repeating
Question Groups
– Nausea Assessment Form uses Repeating
Defaults for Scheduled Times
– Episodes of Nausea Form uses the (internal)
Repeat_sn field of the DCM Cursor for the
episode number
• Forms collected only at the “1 to 24 Hour
Post Op” Event
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Lags in Procedures

13. Validation Procedure …
• Two Procedure Question Groups
– Assessment Group
• SCHEDULED_TIME, ACTUAL_DATE, ACTUAL_TIME and EPISODE_YN
questions available
• Lag Depth of 1 specified for each question
– Episode Group
• ACTUAL_DATE and ACTUAL_TIME questions available
• Question Groups not correlated
– Forms collected at a single event
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Lags in Procedures

14. Validation Procedure
• Qualifying Expressions
– Assessment Group:
• EPISODE_YN in (‘YES’,’NO’) to ignore any scheduled
assessment which is Not Done
– Episode Group:
• Episode ACTUAL DATE TIME is between the lag Assessment
DATE TIME and Current Assessment DATE TIME
• Check ‘Single Repeat Only’ on Episode Group
• Check ‘Create Placeholder’ on Episode Group
• Detail checks EPI$HAS_DATA = ‘N’
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Lags in Procedures

15. Comparing Dates and Times
• Oracle Clinical stores Dates and Times as
separate variables formatted as character
strings: yyyymmdd and hhmmss
• Oracle Clinical Package function
rxc_date.convert, combines and converts
from OC’s format to native Oracle date
datatype
– allows simple date time comparisons
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Lags in Procedures

16. rxc_date.convert Function
rxc_date.convert (OC_DATE, OC_TIME)
RETURN date;
• OC_DATE in YYYYMMDD format
– Partial Date returns null
• OC_TIME in HHMMSS format
– Optional argument – 000000 assumed if absent
– Time can be HH, HHMM or HHMMSS – 00 used to
complete the 6 character time
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Lags in Procedures

17. Episode Group Qualifying
Expression …
EPI.actual_DateTime between
asmt.actual_DateTime$L1
and
asmt.actual_DateTime
is coded
rxc_date.convert(epi.actual_date,epi.actual_time)
between
rxc_date.convert(asmt.actual_date$L1,asmt.actual_time$L1)
and
rxc_date.convert(asmt.actual_date,asmt.actual_time)
But this is not enough!
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Lags in Procedures

18. Episode Group Qualifying
Expression
Need to account for the first assessment!
EPI.actual_DateTime between
nvl(asmt.actual_DateTime$L1, ’01-JAN-1900’)
and
asmt.actual_DateTime
If LAG variable doesn’t yet exist, the value is null!
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Lags in Procedures

19. Detail Expression
Create a discrepancy if
Asmt.EPISODE_YN=‘YES’ and EPI$HAS_DATA=‘N’
Only concerned with And if record found
assessments which by the checking
reported Nausea “create placeholder”
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Lags in Procedures

20. Validation Program Structure
Fetch Patient Data
Initialize Assessment Lags to null
Fetch Current Assessment Repeat where
EPISODE_YN is YES or NO
Fetch 1ST Episode Repeat where DateTime
between last assessment and current
assessment or create a null record if none
Test for null record and that Current
Assessment EPISODE_YN=‘YES’
Set Lag Variables
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Lags in Procedures

21. Limits on Lags
• Lags are initialized to null when the Patient
Information Cursor is fetched
• Lags are set after post-detail code executes
• Always contain data from the previous
occurrence of the Procedure question group
– Independent of the Clinical Planned Event or
Repeat SN
• Could overcome limits with manual
initialization in pre-detail code
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Lags in Procedures

22. Contact Information
Steve Rifkin
BioPharm Systems
908 822 0552
srifkin@biopharm.com
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Lags in Procedures

23. Presenter Bio
Steve Rifkin has over 15 years of Oracle Clinical
experience. As an Oracle Consultant, and then a
Practice Manager at Oracle Clinical consulting, Steve
has assisted about 75 companies with implementation of
Oracle Clinical and RDC, leading the implementation
process, providing training and performing custom
coding. Since joining Biopharm in 2000, Steve has been
responsible for developing Oracle Clinical training
courses, and providing training and implementation
services for Biopharm clients.
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Lags in Procedures

24. ?
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Lags in Procedures