Table 1.

Required data elements for determining real-world time to treatment discontinuation (rwTTD) for a systemic anticancer therapy (SACT) drug in a specific line of therapy (LOT).

Operational steps to ascertain rwTTD and type of data category		Commonly used data elements
Identify records of the drug of interest
	SACT drug	Drug_name, NDCa, HCPCSb code, RxNorm code
	SACT administration	Drug administration datec
	SACT order	Drug order dated
Identify discontinuation date from subsequent LOT start date
	LOT	LOT namee
	LOT	LOT number
	LOT	LOT start date
	LOT	LOT end date
If no subsequent LOT, identify discontinuation date from patient death record during treatment
	Mortality status	Vital status or date of death
If no date of death, identify discontinuation date by last follow-up date subheading
	Last follow-up	Date of last follow-upf

^aNDC: National Drug Code.

^bHCPCS: Healthcare Common Procedure Coding System.

^cThe drug administration date is defined as the date of receiving medication at a health care facility as a medical service, often applicable to an intravenous drug.

^dThe drug order date is defined as the order date for drugs used at home, often applicable to an oral drug.

^eThe LOT name is determined by the combination of SACT drugs administered or ordered from the LOT start to end dates.

^fThe date of last follow-up is defined as the last documented clinic visit or procedure in the electronic health record.