In interventional studies, an arm is a group of study subjects associated with a given treatment assignment. Arm information is required for Complete trials, and is optional for Abbreviated trials.
When adding arms to a trial, you assign to them the interventions currently abstracted for the trial. For instructions on abstracting interventions, refer to Abstracting Interventions.
The following rules apply to each trial:
There must be at least one arm/group that implies that the entire study subject population receives the same intervention.
The number of arms/groups added to the trial must coincide with the number indicated in the trial’s Design Details. See Abstracting Interventional Trial Design Details.
- Every arm must have at least one assigned intervention (except for the arm type "no intervention").
- Every intervention must be assigned to at least one arm.
- There must be only one arm with the same combination of description and associated intervention.
- Arm details for single-arm trials are not required.
Trials can have multiple arm records. Each record displays the following arm information:
Field | Definition |
---|---|
Label | Short name used to identify the arm or comparison group. |
Type | Function of the arm. Valid types are as follows:
|
Description | Brief description of the arm or comparison group to distinguish it from other arms/groups in the trial. |
Assigned Interventions | Intervention(s) assigned to a given arm. 1 |
____
- Interventions imported from ClinicalTrials.gov may not match CTRP terminology. ↩
Adding Arms
How to Add Arms Search for the trial of interest. For instructions, refer to Searching for Trials in PA. In the search results, click the NCI Trial Identifier link for that trial. The Trial Identification page appears. On the Trial Identification page, check out the trial. For instructions, refer to Checking In and Checking Out Trials. (This checkout step is optional for Super Abstractors.) On the Scientific Data menu, click Arms. The Arms page appears, with or without any arm records displayed. In the drop-down lists and text fields, select or enter the appropriate information. The following table describes the fields. An asterisk (*) indicates a required field. Trial Description Instruction Label* Type the descriptive name of the arm. Type* Select the appropriate arm function. Valid values are as follows: Arm Description Type a brief description of the arm. You must provide an arm description or existing intervention description when abstracting multi-arm trials. Assignment For arm types other than No Intervention, select the check box in the column for the intervention assigned to the current arm. You can expand text fields and table cells to reveal all of their content To increase the size of a text field or table cell, click and drag the lower right corner handle.
Editing Arms
How to Edit Arm Records Search for the trial of interest. For instructions, refer to Searching for Trials in PA. In the search results, click the NCI Trial Identifier link for that trial. The Trial Identification page appears. On the Trial Identification page, check out the trial. For instructions, refer to Checking In and Checking Out Trials. (This checkout step is optional for Super Abstractors.) On the Scientific Data menu, click Arms. The Arms page appears. You can expand text fields and table cells to reveal all of their content To increase the size of a text field or table cell, click and drag the lower right corner handle.
The Edit Arm page appears.
Deleting Arms
How to Delete Arms Search for the trial of interest. For instructions, refer to Searching for Trials in PA. In the search results, click the NCI Trial Identifier link for that trial. The Trial Identification page appears. On the Trial Identification page, check out the trial. For instructions, refer to Checking In and Checking Out Trials. (This checkout step is optional for Super Abstractors.) On the Scientific Data menu, click Arms. The Arms page appears. In the Delete column for the appropriate record, click the Delete icon. There is no way to recover a deleted record. If you delete a record accidentally, follow the instructions in Adding Arms to add it back.