Tobacco products come in a variety of forms that are used in different ways. It is available as skin patches, chewing gum, nasal and oral sprays, inhalers, lozenges and tablets.
Vapes, vaporizers, vape pens, hookah pens, electronic cigarettes (e-cigarettes or e-cigs), e-cigars, and e-pipes are some of the many tobacco product terms used to describe electronic nicotine delivery systems (ENDS). These products use an “e-liquid” that usually contains nicotine derived from tobacco, as well as flavorings, propylene glycol, vegetable glycerin, and other ingredients. The liquid is heated to create an aerosol that the user inhales.
Self-report of nicotine exposure often may be biased and lead to inaccurate measures of exposure. Hence, biomarkers are often used to provide objective measure of nicotine exposure. Studies on tobacco product typically collect the quantities of the tobacco product used through self-reporting, while the actual nicotine exposure is measured by biomarkers.
Studies may be performed under controlled circumstances in clinics. In these studies, subject may use the study tobacco product of interest ad-librium, or as specified in the protocol.
Data on the study product of interest are reported in the Exposure as Collected (EC), the Exposure (EX) domains as well as the Product Accountability Domain (DA). The DA domain represents details on amount of study product dispensed and returned.
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 used.
The domains needed to represent the exposure in a tobacco product study is decided by the sponsor. Some sponsor 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 study purpose and analysis. More detail summarization may also be performed in ADaM. In some situation, sponsor may elected to only use the EX, and if needed the DA domain. EX would be used-when little relevant information is represented in EC, in a sense EC and EX are essentially duplicates of each other.
The EX domain is required for all studies that include protocol-specified study treatment. 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 drug by the investigator
- Derived from 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 treatment doses cannot yet be reflected in the protocol-specified unit due to blinding requirements, then the EX domain is not expected to be populated.