Table 1. Intervention Component Details of the CO-IMPACT and Standard Care Arms^a.

Timeline	Component	Participants	Deliverer, mode	Content and topics addressed
Enrollmentb	Self-monitoring equipment and general diabetes information	P, S	RA, in person	Patients in both arms were offered glucometers, blood pressure monitors, and a handbook with general diabetes information
Within 1 mo of enrollment	Initial 1-1.5 h coaching session	P, S	Dyad coach, synchronous in person	Patient’s current diabetes complications risk status and diabetes management regimen, including medications Positive communication techniques, emphasizing regular weekly talks about diabetes; open and nonjudgmental communication; and autonomy-supportive communication Dyadic approaches to action planning and engaging in medical visits; “who’s who” on the primary care team
	CO-IMPACT handbook and website	P, S	NA	Information on each topic discussed during the initial session Information on each topic covered in the IVR calls
From the date of the initial coaching session to a date 12 mo after the patient baseline survey (approximately 11 mo)	IVR calls every 2 wk	P	Automated phone call	Automated voice-response inquiries asked patient to (1) indicate whether any of several events occurred during the past 2 wk (high or low blood glucose or blood pressure, problems with home monitors, medication access or adherence concerns, sick days, new foot problems, and readiness to quit smoking) and (2) rate how important they felt identified issues were to address Tips on how to address important issues, including a prompt to make an action plan Prompts to engage in self-monitoring Selected issues flagged as urgent resulted in an automated fax to the patient’s primary care team
	IVR summary with follow-up tips	S	Automated email	Summary of patient’s responses to IVR calls as well as identified health issues and their importance to the patient Advice on how supporters could help patients address identified issues, with links to relevant content in the study handbook and website Reminders to use positive, autonomy-supportive communication with the patient
	Visit reminder 2-5 d before each scheduled clinic visit	S	Dyad coach, email	Reminder from the coach that the patient has an upcoming clinic appointment and to use the visit preparation worksheet to discuss the appointment with the patient Invitation to supporter to participate in the CO-IMPACT clinic-visit preparation call with the coach
	Visit preparation calls 2-5 d before each scheduled clinic visit	P and/or S	Dyad coach, synchronous telephone discussion	Prompts from the coach to list issues the patient wanted to discuss and information they wanted to bring to the clinic visit (such as home glucose logs) Suggestion from the coach that the patient indicate how they wanted their supporter to help them prepare for the visit or participate in the visit with them Request for supporter to suggest any additional issues they felt the patient should include in the visit
	Visit summaries	P, S	Dyad coach, mailed or posted to website automatically after a completed visit	Customized summary describing diabetes-related details of the patient’s recent clinic visit

Abbreviations: IVR, interactive voice response; NA, not applicable; P, patient participant; RA, research assistant; S, supporter participant.

^a Termed enhanced usual care in initial protocols.

^b Received by participants in both arms (CO-IMPACT and standard care).