SDTM Example. Study Product Exposure and Other Recreational Drug Use

In this study, subjects were randomized to different doses of a nicotine inhaler. The recommended usage instructions for the nicotine inhaler were provided to the subject at each visit. At visits 1-3, subjects were to use 6-10 cartridges per day, and during visits 4-6 subjects were to use 3-6 cartridges per day. Subjects were encouraged not to use any other tobacco products, nicotine replacement therapies, or alcohol during the study. Data on usage of these products were collected using an e-diary, where subjects provided information on the products used each day. Only days where a product was used were represented. 

Alcohol usage and tobacco product usage were represented in the Substance Use (SU) domain. SUCAT allows the records to be grouped into tobacco-related data and alcohol-related data. In this example, the products were prespecified so SUTRT does not require a standardized SUDECOD equivalent. The applicant only includes SUSTDTC and SUENDTC as timing variables.   

Drugs used to treat nicotine dependency are considered drugs and were represented in the Concomitant Medication (CM) domain. This subject used a 14 mg nicotine replacement patch. The applicant included the CMCLASS, CMDECOD, and CMMODIFY. These were included to reflect standardized coding of the medication.  

The Product Accountability (DA) domain was used to represent the amount of study product transferred to or from the study subjects. At each visit, each subject was supplied with 90 cartridges per week for weeks 1-3, and 50 cartridges per week for weeks 4-6. The number of cartridges returned were counted. DACAT was used to indicate that the product of interest was the study product. DASPID and DAREFID can be used for code numbers that appeared on the study product label; in this case, no code numbers were included on the labels. The applicant included VISITNUM and DADTC as these variables are expected in this domain. DADTC was the date the supplies were dispensed or returned, these corresponded to the dates of the visits.   

The applicant used a patient diary (not shown here) to determine how many cartridges the subject used on each day, then created the EC data to represent the collected exposure data. Usage recommendations were represented in ECDOSRGM, which is the intended dose regimen. The ECMOOD permissible variable was used to reflect the prescribed and the actual usage of the inhaled nicotine. When this variable is used, it must be populated for all records. This variable cannot be used in EX.   

The EX dataset shows actual administrations. Scheduled records are not included, and only a few rows are shown for illustration purposes. The pharmaceutical strength was included to identify the dose of the nicotine inhaler used by the subject. Because EXENDTC is an expected variable, the applicant populated this timing variable with the start date.