Table 1 Study assignment approach for each preference and enrollment date scenario

 No preference between interventions

Randomly assigned to one of the four study arms: three interventions without waitlist and the waitlist arm, with a 1:1:1:1 ratio.

 Preferred two interventions equally and over the third intervention

Randomly assigned to one of the two interventions with a 1:1 ratio, and then, a fraction was randomly assigned to the waitlist arm, with a 3:1 non-waitlist vs waitlist ratio for MBSR and stress proofing and a 5:4 non-waitlist vs waitlist ratio for the Daily Examen (DE was preferred by more participants and this allowed the same number of participants to be randomized into each study arm).

 Preferred one intervention among the three

Assigned to their preferred intervention and combined with participants with two top preferences who had been randomized to that intervention, and then randomly assigned to non-waitlist vs waitlist arms, with a 3:1 non-waitlist vs waitlist ratio for MBSR and stress proofing and a 5:4 non-waitlist vs waitlist ratio for the Daily Examen.

 Any of the above scenarios and are part of a married or cohabitating couple who both meet study criteria and enrolled

To avoid spillover effects, each couple was treated as if they were one person, i.e., assigning both spouses to the same intervention and randomizing them into a non-waitlist vs waitlist arm. When a couple had different preferences, one preference was randomly chosen as the couple’s preference.

 Seven clergy with an established meeting group (a covenant group)

The seven clergy jointly chose a single preferred intervention and were randomized together to the non-waitlist vs waitlist arm.

 All enrollees after March 1, 2020, with no preference, two equal preferences, or one preference, and whether a clergy couple or not

Participants answered treatment preference survey items, but regardless of their answers, self-selected the intervention with intervention dates they most wanted from the full list of workshop options. None was randomized to the non-waitlist vs waitlist arms; they all were assigned to non-waitlist.