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Trial Design Introduction. Elke Sennewald , 22 September 2011. Trial Design Domains. Information about study design No subject data Describe the overall trial design and plan via data representation. Why Do Trial Design. Rapidly understanding the design of the study
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Trial Design Introduction ElkeSennewald, 22 September 2011
Trial Design Domains • Information about study design • No subject data • Describe the overall trial design and plan via data representation
Why Do Trial Design • Rapidly understanding the design of the study • Standard and relatively simple data structures • Relatively small number of rows of data and easy to comprehend • Useful for both FDA reviewers and internal sponsor use • Information can be centrally accessible and searchable
Trial Design Datasets Trial Arms (TA) Trial Elements (TE) Trial Visits (TV) Trial Inclusion /Exclusion (TI) Trial Summary (TS) Start thinking about this before you start the other SDTM datasets!
Trial Summary (TS) Dataset • Summary of trial information • No link to subject-level data in SDTM • TSGRPID used to group multiple related parameters such as Dose, Units, Frequency etc • TSSEQ used as a key for multiple records with the same parameters • Common questions: • What need to be included? • Why are we generating this?
Trial Inclusion/Exclusion (TI) • Not subject-oriented • Link to IE domain • STUDYID, IECAT, IETESTCD, IETEST • Subject IETEST/IETESTDC must match Trial Inclusion/Exclusion IETEST/IETESTCD • Best to create TI first, before you tackle IE • Common questions: • How to truncate if >200 characters? • Truncation – potential for duplicate IETEST values • Protocol amendment: do we need to add to TI only the changed criteria or all criteria? • Local amendment
TA / TE / TV datasets A data representation on the different epochs, arms and visit structure in the study Where to start? Is there a systematic approach?
Example 1 – Trial Design Schema Drug A Follow-up Screen Drug B Follow-up
Epoch Drug A Follow-up Screen Drug B Follow-up EPOCH Screening Follow-up Treatment
Arm / Treatment Strategy Drug A Follow-up ARM(Treatment Strategy) Screen Drug B Follow-up Screening Follow-up Treatment 1 2
Arm / Treatment Strategy Drug A Follow-up Screen Study Cell Drug B Follow-up Screening Follow-up Treatment 1 Screen Drug A Follow-up 2 Screen Drug B Follow-up
Trial Design Matrix Screening Follow-up Treatment A Screen Drug A Follow-up B Screen Drug B Follow-up
TE (Trial Elements) Screen Drug A Drug B Follow-up • What are the elements? • Unique study cell values (=ELEMENT)
Screen Run-In Placebo Screen Run-In Drug A Screen Run-In Drug B Trial Arms and Elements Overview Screen Run-in Placebo Trial Elements describes the Elements and the rules for the start and end of each. Drug A Drug B Trial Arms describes the Elements in each Arm, their order and Epoch, and any branching or transition rules. Placebo Drug A Drug B Epochs are described only in Trial Arms, and have no separate table. Screening Run-In Treatment Trial Visits describes the planned Visits for each Arm, and any start and end rules. Visit 1 Visit 2 Visit 3 Visit 4 Visit 5
Trial Design Matrix Screening Run-in Treatment P Screen Run-in Placebo A Screen Run-in Drug A B Screen Drug B Run-in
Creating Trial Elements (1) • Usually the most challenging dataset • Not a duplication of EX (Exposure) • Assign an element code (ETCD) to each value, define the start of each element (TESTRL) and end of each element (TEENRL or TEDUR) • Start rules are the most important • Subject data must exist to support the creation of these • Start of next element defines end of previous
Example pseudocode: EXSTDTC where EXTRT = RUN-IN DRUG Example pseudocode: DSSTDTC where DSDECOD = INFORMED CONSENT Creating Trial Elements (2) Screen Run-in Placebo Trial Elements describes the Elements and the rules for the start and end of each. Drug A Drug B
TE -> SE (Subject Elements) • Shows the trial progress of each subject • Whether a subject passes through each element • Timing of each element
EXSTDTC where EXTRT = RUN-IN DRUG DSSTDTC where DSDECOD = INFORMED CONSENT Creating Subject Elements
Trial Arms (TA) Dataset High level treatment plan Composed of Elements from Trial Elements Go back to the Trial Design Matrix 1 study cell = 1 row of record in TA So in our example we expect 9 rows of record Planned ARM values in DM correspond to ARM values in Trial Arms Names of ARM should reflect the protocol
Screen Run-In Placebo Screen Run-In Drug A Screen Run-In Drug B Creating Trial Arms Placebo Drug A Drug B
Trial Visit (TV) Dataset • Describe the planned visits in a trial • VISITNUM and TRSTRL is required • ARMCD expected • VISIT and VISITDY permissible • 1 record per planned visit per arm • A “visit” may span over several days (eg screening visit) • What is really the start and end of a visit? • Create Subject Visits dataset from Visit based SDTM datasets
TV -> SV (Subject Visits) • Shows the actual visits of each subject • Compare against the scheduled/planned visits or assessments in TV • Include unscheduled visits • Designation of VISITNUM becomes crucial • Whole number for planned visits • Decimals for unscheduled visits in SV – and slot into right place
Creating Trial Visits • Planned schedule of Visits • Challenge is in defining start and end of a visit • ARM/ARMCD can be used if schedule varies by Arm
Summary • Construction of TA/TE/TV • Study Schema Epoch Arm Study Cells • Unique study cells = rows in TE • All study cells = rows in TA • If all arms have same visits, then 1 set of visits for all arms. Otherwise 1 set of visits for each arm. • Complex study designs • Systematic approach will make life easier • Think at protocol/CRF design stage – don’t wait till the end • Details vs ease of use