A trial design domain that provides information on the protocol-specified disease assessment schedule, to be used for comparison with the actual occurrence of the efficacy assessments in order to determine whether there was good compliance with the schedule.
TD – Specification td.xpt,Trial Disease Assessments—Trial Design.One record per planned constant assessment period,Tabulation
SDTMIG v3.4 Metadata Check for Domain Specification Table 1.4.1
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Release Notes
A number given to ensure ordinal sequencing of the planned assessment schedules within a trial.
Req
TDANCVAR
Anchor Variable Name
Char
Timing
A reference to the date variable name that provides the start point from which the planned disease assessment schedule is measured. This must be a referenced from the ADaM ADSL dataset (e.g., "ANCH1DT"). Note: TDANCVAR will contain the name of a reference date variable.
Req
TDSTOFF
Offset from the Anchor
Char
ISO 8601 duration
Timing
A fixed offset from the date provided by the variable referenced in TDANCVAR. This is used when the timing of planned cycles does not start on the exact day referenced in the variable indicated in TDANCVAR. The value of this variable will be either zero or a positive value and will be represented in ISO 8601 character format.
Req
TDTGTPAI
Planned Assessment Interval
Char
ISO 8601 duration
Timing
The planned interval between disease assessments represented in ISO 8601 character format.
Req
TDMINPAI
Planned Assessment Interval Minimum
Char
ISO 8601 duration
Timing
The lower limit of the allowed range for the planned interval between disease assessments represented in ISO 8601 character format.
Req
TDMAXPAI
Planned Assessment Interval Maximum
Char
ISO 8601 duration
Timing
The upper limit of the allowed range for the planned interval between disease assessments represented in ISO 8601 character format.
Req
TDNUMRPT
Maximum Number of Actual Assessments
Num
Record Qualifier
This variable must represent the maximum number of actual assessments for the analysis that this disease assessment schedule describes. In a trial where the maximum number of assessments is not defined explicitly in the protocol (e.g., assessments occur until death), TDNUMRPT should represent the maximum number of disease assessments that support the efficacy analysis encountered by any subject across the trial at that point in time.
Req
1In this column, an asterisk (*) indicates that the variable may be subject to controlled terminology. CDISC/NCI codelist values are enclosed in parentheses.
The purpose of the Trial Disease Assessments (TD) domain is to provide information on planned scheduling of disease assessments when the scheduling of disease assessments is not necessarily tied to the scheduling of visits. In oncology studies, compliance with the disease-assessment schedule is essential to reduce the risk of "assessment time bias." The TD domain makes possible an evaluation of assessment time bias from the SDTM, in particular for studies with progression-free survival (PFS) endpoints. TD has limited utility within oncology and was developed specifically with RECIST in mind and where an assessment-time bias analysis is appropriate. It is understood that extending this approach to Cheson and other criteria may not be appropriate or may pose difficulties. It is also understood that this approach may not be necessary in non-oncology studies, although it is available for use if appropriate.
A planned schedule of assessments will have a defined start point; the TDANCVAR variable is used to identify the variable in the ADaM subject-level dataset (ADSL) that holds the “anchor” date. By default, the anchor variable for the first pattern is ANCH1DT. An anchor date must be provided for each pattern of assessments, and each anchor variable must exist in ADSL. TDANCVAR is therefore a Required variable. Anchor date variable names should adhere to ADaM variable naming conventions (e.g. ANCH1DT, ANCH2DT). One anchor date may be used to anchor more than 1 pattern of disease assessments. When that is the case, the appropriate offset for the start of a subsequent pattern, represented as an ISO 8601 duration value, should be provided in the TDSTOFF variable.
The TDSTOFF variable is used in conjunction with the anchor date value (from the anchor date variable identified in TDANCVAR). If the pattern of disease assessments does not start exactly on a date collected on the CRF, this variable will represent the offset between the anchor date value and the start date of the pattern of disease assessments. This may be a positive or zero interval value represent in an ISO 8601 format.
A pattern of assessments consists of a series of intervals of equal duration, each followed by an assessment. Thus, the first assessment in a pattern is planned to occur at the anchor date (given by the variable named in TDANCVAR) plus the offset (TDSTOFF) plus the target assessment interval (TDTGTPAI). A baseline evaluation is usually not preceded by an interval, and would therefore not be considered part of an assessment pattern.
This domain should not be created when the disease assessment schedule may vary for individual subjects (e.g., when completion of the first phase of a study is event-driven).
This example shows a study where the disease assessment schedule changes over the course of the study. In this example, there are 3 distinct disease-assessment schedule patterns. A single anchor date variable (TDANCVAR) provides the anchor date for each pattern. The offset variable (TDSTOFF), used in conjunction with the anchor date variable, provides the start point of each pattern of assessments..
The first disease-assessment schedule pattern starts at the reference start date (identified in the ADSL ANCH1DT variable) and repeats every 8 weeks for a total of 6 repeated assessments (i.e., week 8, week 16, week 24, week 32, week 40, week 48). Note that there is an upper and lower limit around the planned disease assessment target where the first assessment (8 weeks) could occur as early as day 53 and as late as week 9. This upper and lower limit (-3 days, +1 week) would be applied to all assessments during that pattern.
The second disease assessment schedule starts from week 48 and repeats every 12 weeks for a total of 4 repeats (i.e., week 60, week 72, week 84, week 96), with respective upper and lower limits of -1 week and + 1 week.
The third disease assessment schedule starts from week 96 and repeats every 24 weeks (week 120, week 144, and so on), with respective upper and lower limits of -1 week and + 1 week, for an indefinite length of time. The preceding schematic shows that, for the third pattern, assessments will occur until disease progression; this therefore leaves the pattern open-ended. However, when data is included in an analysis, the total number of repeats can be identified and the highest number of repeat assessments for any subject in that pattern must be recorded in the TDNUMRPT variable on the final pattern record.
td.xpt
td.xpt
Row
STUDYID
DOMAIN
TDORDER
TDANCVAR
TDSTOFF
TDTGTPAI
TDMINPAI
TDMAXPAI
TDNUMRPT
1
ABC123
TD
1
ANCH1DT
P0D
P8W
P53D
P9W
6
2
ABC123
TD
2
ANCH1DT
P48W
P12W
P11W
P13W
4
3
ABC123
TD
3
ANCH1DT
P96W
P24W
P23W
P25W
12
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This example shows a crossover study, where subjects are given the period 1 treatment according to the first disease-assessment schedule until disease progression, then there is a rest period of 28 days prior to the start of period 2 treatment (i.e., re-baseline for period 2). The subjects are then given the period 2 treatment according to the second disease assessment schedule until disease progression. This example also shows how two different reference/anchor dates can be used.
The Rest element is not represented as a row in the TD dataset, since no disease assessments occur during the Rest. Note that although the Rest epoch in this example is not important for TD, it is important that it is represented in other trial design datasets.
Row 1:
Shows the disease assessment schedule for the first treatment period. The diagram above shows that this schedule repeats until disease progression. After the trial ended, the maximum number of repeats in this schedule was determined to be 6, so that is the value in TDNUMRPT for this schedule.
Row 2:
Shows the disease assessment schedule for the second period. The pattern starts on the date identified in the ADSL variable ANCH2DT and repeats every 8 weeks with respective upper and lower limits of -1 week and + 1 week,. The maximum number of repeats that occurred on this schedule was 4.
td.xpt
td.xpt
Row
STUDYID
DOMAIN
TDORDER
TDANCVAR
TDSTOFF
TDTGTPAI
TDMINPAI
TDMAXPAI
TDNUMRPT
1
ABC123
TD
1
ANCH1DT
P0D
P8W
P53D
P9W
6
2
ABC123
TD
2
ANCH2DT
P0D
P8W
P53D
P9W
4
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Dataset Wrapper Debug Message
Please add a row column to your dataset.
This example shows a study where subjects are randomized to standard treatment or an experimental treatment. The subjects who are randomized to standard treatment are given the option to receive experimental treatment after they end the standard treatment (e.g., due to disease progression on standard treatment). In the randomized treatment epoch, the disease assessment schedule changes over the course of the study. At the start of the extension treatment epoch, subjects are re-baselined, i.e., an extension baseline disease assessment is performed and the disease assessment schedule is restarted).
In this example, there are 3 distinct disease-assessment schedule patterns:
The first disease-assessment schedule pattern starts at the reference start date (identified in the ADSL ANCH1DT variable) and repeats every 8 weeks for a total of 6 repeats ( i.e., week 8, week 16, week 24, week 32, week 40, week 48), with respective upper and lower limits of - 3 days and + 1 week.
The second disease assessment schedule starts from week 48 and repeats every 12 weeks (week 60, week 72, etc.), with respective upper and lower limits of -1 week and + 1 week, for an indefinite length of time. The preceding schematic shows that, for the second pattern, assessments will occur until disease progression; this therefore leaves the pattern open-ended.
The third disease assessment schedule starts at the extension reference start date (identified in the ADSL ANCH2DT variable) from week 96 and repeats every 24 weeks (week 120, week 144, etc.), with respective upper and lower limits of -1 week and + 1 week, for an indefinite length of time. The schematic shows that, for the third pattern, assessments will occur until disease progression; this therefore leaves the pattern open-ended.
For open-ended patterns, the total number of repeats can be identified when the data analysis is performed; the highest number of repeat assessments for any subject in that pattern must be recorded in the TDNUMRPT variable on the final pattern record.