TOBA-171 - Getting issue details... STATUS Self-reporting of nicotine exposure often may be biased and lead to inaccurate measures of exposure. Hence, biomarkers are often used to provide objective measures of nicotine exposure. Studies on tobacco products typically collect the quantities of the tobacco product used through self-reporting, while the actual nicotine exposure is measured by biomarkers.
Studies evaluate the protocol-specified study product exposure. These study products are typically supplied by the sponsor. However, sponsors often collect exposure to other nicotine sources.
The subject's normal nicotine product usage (e.g., usually brand of cigarettes, nicotine replacement patches) may be allowed, or discouraged in the study. These products are not supplied by the sponsor, and are not considered a study product. The use of these products would be represented in the SU ( for cigarettes and CM (for nicotine replacements patches) domains.
Studies may be performed under controlled circumstances in clinics, to ensure that the only nicotine exposure is the study product itself.
Exposure data on the study product of interest are reported in the Exposure as Collected (EC) and/or the Exposure (EX) domains as well as the Product Accountability Domain (DA).
- The Product Accountability (DA) domain is based on the Findings General Observation class. This domain represents the accountability of study products, such as information on the receipt, dispensing, return, and packaging.
- The Exposure as Collected (EC) domain is based on the Interventions General Observation class, This domain represents information about protocol-specified studyproduct administrations, as collected.
- The Exposure (EX) domain is based on the Interventions General Observation class. This domain represents a subject's exposure to protocol-specified study product. Study product is usually an intervention that is prospectively defined as a test material within a study, and is typically but not always supplied to the subject.
The Exposure as collected (EC) domain is typically used to reflect amounts at the product-level (e.g., number or cigarettes, number of cartridges, number of patches etc and not the actual exposure to the product. The actual exposure to the product would then be represented in EX. The EX data exposure is derived from EC, Product Accountability Domain (DA) and the protocol-specific details on the study product.
The domains needed to represent the exposure in a tobacco product study is decided by the sponsor. Some sponsors use the EC domain to reflect the collected exposure data, and then derive EX. The degree of summarization of records from EC to EX is sponsor-defined and is used to support the study purpose and analysis. EX derivations must be described in the Define-XML document. More detail summarization may also be performed in ADaM. For example, the estimated daily nicotine exposure may based on self-reported nicotine exposure may be provided. Since, these are estimates, they are typically not reported in EX.
Sponsors may find it easier to report both the collected data in EC and the derived EX data to provide tracking of the summarized exposure to what was collected.
In some situation, sponsors may elect to only use the EX and, if needed, the DA domain. EX would be used when little relevant information is represented in EC (i.e., when EC and EX would essentially be duplicates of each other). For example, the derivation for EX may just be the unmasking of the product, and a sponsor may decide not to show the EC because the derivations used for EX are obvious.
The EX domain is required for all studies that include protocol-specified study product exposure. Exposure records may be directly or indirectly determined; metadata should describe how the records were derived. Common methods for determining exposure (from most direct to least direct) include the following:
- Derived from actual observation of the administration of study product by the investigator
- Derived from an automated dispensing device that records administrations
- Derived from subject recall
- Derived from product accountability data
- Derived from the protocol. When a study is still masked and protocol-specified study product exposure cannot yet be reflected in the protocol-specified unit due to blinding requirements, then the EX domain is not expected to be populated.