Table 3.

Standard Protocol Items: Recommendations for Interventional Trials schedule of enrollment, interventions, and assessments.

Data collected				Method
Screening
	Eligibility and demographic information		Brief standard demographic characteristics (eg, age and education) and inclusion and exclusion information collected through structured questions.
Primary outcome
	Knowledge assessment of breast cancer risk factors		Participants were asked to demonstrate their knowledge of breast cancer risk associated with 6 factors (eg, family history of breast cancer, physical inactivity, antiperspirant deodorant use, alcohol, processed meats, and excess weight) by selecting from a set of scaled-response options: (1) a clear breast cancer risk factor with strong, consistent evidence; (2) a possible risk factor with some evidence; (3) not a proven risk factor with too limited evidence to determine risk; or (4) do not know. Primary outcome was the proportion of participants identifying alcohol as a clear breast cancer risk factor at 4 weeks. Adapted from Cancer Australia’s 2018 definitions of breast cancer risk factors and previous research with breast screening service consumers [48,53].
Secondary outcomes
	Alcohola
		14-day TLFBb	Alcohol consumption over past 14 days assessed with TLFB [45]. TLFB also informed personalized feedback provided in the alcohol brief intervention.
		AIHWc alcohol frequency and quantity items	Past-month frequency of alcohol consumption and volume of alcohol consumption on a typical drinking day assessed with 2 items from the AIHW National Drug Strategy Household Survey [46,47].
		Assessment of alcohol health literacy	Adapted from previous research with breast screening service consumers, participants were asked about (1) attitudes to alcohol and breast cancer risk [48]; (2) alcohol health knowledge (eg, amount of alcohol in a standard drink, number of standard drinks in an average restaurant serve of alcohol, maximum number of standard drinks recommended by current health guidelines) [10]; and (3) access to alcohol and breast cancer health information [54]. Questions were presented in multiple-choice, open-ended, or statement (ie, 5-point Likert scale from strongly agree to strongly disagree) formats.
	Health and well-being
		European Health Interview Survey-QOLd single item	QOL rated as single item on 5-point Likert scale from very poor to very good [50].
		SF-12e	SF-12 used as a brief measure of general health [49].
		Physical activity duration [51,52] and consumption of vegetables and fruit [52]	Brief physical activity and vegetable and fruit intake questions included to ensure blinding of participants. Questions adapted from the Australian Bureau of Statistics and previous research [51,52].

^aAlcohol assessments were nested among general health and lifestyle questions to conceal the trial’s alcohol focus.

^bTLFB: timeline follow-back.

^cAIHW: Australian Institute of Health and Welfare.

^dQOL: quality of life.

^eSF-12: 12-item Short-Form Health Survey.