Study protocol for a factorial-randomized controlled trial evaluating the implementation, costs, effectiveness, and sustainment of digital therapeutics for substance use disorder in primary care (DIGITS Trial)

Table 1 Timing of the DIGITS Trial’s assessment schedules, following SPIRIT 2013 guidelines (Standard Protocol Items: Recommendations for Interventional Trials)

	Enrollment	Allocation	Post-allocation								Close-out
TIMEPOINT	-t₁	0	t₁	t₂	t₃	t₄	t₅	t₆	t₇	t₈	t_x
ENROLLMENT:
Clinic eligibility assessment	X
Allocation to study arm¹		X
PERIODS:
Active implementation			X	X	X	X
Sustainment							X	X	X	X
INTERVENTIONS:
reSET & reSET-O availability			X	X	X	X	X	X	X	X
Standard implementation			X	X	X	X
Practice facilitation			X	X	X	X
Health coaching			X	X	X	X
ASSESSMENTS:
Covariates²	X	X	X	X	X	X	X	X	X	X
Implementation costs	X	X	X	X	X	X
Reach³ & adoption			X	X	X	X
Fidelity, engagement			X	X	X	X	X
Substance use, abstinence from screening data			X	X	X	X	X	X	X	X	X
Substance use, abstinence from reSET & reSET-O data			X	X	X	X	X
Sustainment							X	X	X	X

t₁ through t₈ are discrete 3-month periods. Sites with shorter active implementation and sustainment periods have shorter assessment periods. For instance, the reach & adoption assessment period will be 7 months for a site with a 7-month active implementation period.
¹While sites are allocated to arms upon randomization, an open cohort design is used to identify patients for the analysis. Patients who visit a site after randomization, or in the 2 weeks before randomization, are eligible for the analysis. This 2-week period before randomization allows for the possibility that clinicians will identify patients with recent visits who could benefit from the intervention. ²Patient covariates are assessed in the year prior to a patient’s qualifying visit. ³For each patient, we will identify whether they were reached from the day of their first qualifying visit through the end of the active implementation period plus a 2 week “grace” period. The grace period allows patients who have their first qualifying visit at the end of active implementation at least 2 weeks to be reached.

ISSN: 1748-5908