Table 1.

Overview of phase-wide data collection methods and measures-Harris County, Texas (2021-2025).

Construct			Measure		Study week		Source
Eligibility
	SUDa	Substance use and co-occurring mental health diagnoses (Mini International Neuropsychiatric Interview)		0		SUD intake records
PrEP knowledge and attitudes (based on barriers identified in aim 1)
	PrEPb knowledge	PrEP knowledge questionnaire [62]		0, 4, 10, 16		REDCapc survey
	PrEP attitudes	PrEP Attitudes Measure [63]		0, 4, 10, 16		REDCap survey
	PrEP stigma	PrEP Anticipated Stigma Scale (PASS) [64]		0, 4, 10, 16		REDCap survey
	PrEP adherence self-efficacy	Adherence Starts with Knowledge (ASK-20) [65]		0, 4, 10, 16		REDCap survey
	HIV risk behaviors	Risk Assessment Battery [66]		0, 4, 10, 16		REDCap survey
	HIV risk perceptions	Perceived Risk of HIV Scale [67]		0, 4, 10, 16		REDCap survey
Initial efficacy (aim 3)
	PrEP eligibility	HIV screening, viral hepatitis screening, pregnancy screening, screening for sexually transmitted diseases, and behavioral risk factors		4, 16, 4		Laboratory results Nurse interview
	PrEP uptake (primary outcome)	PrEP prescription filled and self-reported initial dose of PrEP taken		10, 16		Self-report
	PrEP adherence (behavioral)	Video-confirmed dose (intervention, daily oral PrEP) Video-confirmed dose (intervention, long-acting injectable [LAI] PrEP, and initial oral cabotegravir) Follow-up injection (intervention LAI) Self-reported dose daily oral PrEP (intervention and standard treatment)		5-16 n/a and 5-16		Scene health reports, study records, study records, and weekly online survey
	PrEP adherence (laboratory-confirmed)	Tenofovir concentrations (>1000 ng/mL)		16		Laboratory results
Feasibility measures (aim 3)
	Enrollment rate	Proportion screened who are eligible Proportion eligible who consent		—d		Study records
	Session attendance	Proportion of motivational enhancement sessions attended		—		Study records
	Use of Scene Health app	Proportion of medication adherence videos uploaded		—		Scene Health reports
	Study retention	Proportion of participants who remain in the study at 12-week follow-up		—		Study records
Acceptability measures (aim 3)
	Client satisfaction	Client satisfaction questionnaire		4, 16		REDCap survey
Other covariates
	Substance use severity	NIDA-Modified Alcohol, Smoking, and Substance Involvement Screening Test [68]		0, 4, 10, 16		REDCap survey
	Alcohol	Alcohol Use Disorders Identification Test [69]		0, 4, 10, 16		REDCap survey
	Health literacy	Calgary Charter on Health Literacy Scale [70]		0		REDCap survey
	Medical mistrust	Group Based Medical Mistrust Scale [71]		0, 4, 10, 16		REDCap survey
	Trauma	Life Events Checklist/PTSDe Checklist for DSM-5f [72,73]		0, 4, 10, 16		REDCap survey
	Depression	Patient Health Questionnaire-9 [74]		0, 4, 10, 16		REDCap survey
	SUD treatment attendance	Number of substance use disorder therapy sessions attended		16		Study records

^aSUD: Substance use disorder.

^bPrEP: pre-exposure prophylaxis.

^cREDCap: Research Electronic Data Capture.

^dNot applicable.

^ePTSD: posttraumatic stress disorder.

^fDSM-5: Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).