Table 1.

Case Examples of the Design Characteristics PA Intervention Studies with Older Adults that Used Peers

	Case Example 1: A Peer Support Approach	Case Example 2: A Hybrid Peer-delivered with Peer Support Approach
The Study	Matz-Costa et al. (under review ). - A pilot randomized trial of an intervention to enhance the health-promoting effects of older adults’ activity portfolios - 15 adults aged 65 years or older were randomized to receive technology-assisted self-monitoring only and 15 to receive technology-assisted self-monitoring, b) psychoeducation + goal setting via a 3-hr workshop, and c) one-on-one peer support (via phone 2×/week for 3 weeks) to support goal implementation. - Primary outcome was physical activity as measured by steps per day (FITBIT® pedometers)	Castaneda-Sceppa et al. (under review ). - A pilot randomized trial to examined whether improved physical function from engaging in a community-based, group exercise program would favorably influence emotional regulation and free-living PA among community-dwelling frail older adults. - 20 community-dwelling frail older adults were randomized to group exercise once a week or an attention-control group on a ratio of 2:1.
Function/Role of Peer	Peer-assisted strategy: Peer support - During a 2-hr, in-person session, peers were trained to offer: (a) moral support, by being supportive and caring as their peer works toward their stated goals, (b) informational support, by providing personal life examples of success and overcoming barriers, and (c) problem-solving support, by working to facilitate a conversation or reflection to assist their peer in overcoming barriers to achieving their stated goals. Peer supporters were trained as facilitators and supporters, not teachers/motivators, and to avoid any direct teaching/advising to the program participant such as telling the program participant that what they are doing is “wrong”, or formulating goals for the program participants (i.e., program participants were to create and implement their own, personalized goals). In addition to laying out these roles and responsibilities of the peer supporter, training included an overview of the program their peers would be participating in, followed by content, discussion and role play activities on general communication and interpersonal skills, active listening, critical thinking, and strategies for engaging participants, and ethics and resources.	Hybrid peer-delivered and peer-assisted strategy - Participants in the exercise group met as a group once a week to perform upper and lower body strength, balance and core exercises led by a staff member in partnership with a group participant willing to serve at the “peer” for the group or liaison between the participants and the staff. This peer communicated with participants once per week during a different day from the trainer-led group exercise time when participants, peer and community-based staff gathered in the community-based organization to exercise and socialize together. Because the peer was also a program participant, they would fall into the role of peer support in our typology, in that they were helping other participants to work toward the accomplishment of their goals and providing moral support.
Basis for the peer relationship	Similar-age and a lack of professional training or status. Here, the aim was for the relationship to be perceived as one of equality, and for there to be a low power/status differential. Most, but not all of the peers for this study lived in the same city as the participants and peers were generally active older adults.	Similar-age and a lack of professional training or status. - In this instance, there was a very low power/status differential, as peers were also program participants.
Setting	A community-based setting that serves older adults: A Council on Aging/senior center	A community-based setting where older frail and sedentary adults were receiving support services
Modality	Face-to-face, one-to-group and telephone, one-on-one - An initial face-to-face meeting in a small group setting (one-to-group), and then subsequent one-on-one telephone sessions	Face-to-face, one-to-group - As cofacilitators of the exercise group once a week and informally provided support as program participants gathered in the community-based organization to exercise and socialize together.
Level of formality or structure	Informal/nonstructured - Peers were given a good deal of latitude in how they structured their interactions with their peers, so long as they maintained the facilitator/support type of role, thus the structure was informal rather than prescribed.	Informal/nonstructured - Peers were participants of the study who self-identified as peers to provide social support to the fellow participants; the structure was not prescribed.
Peer assignment strategy	No matching, random - Each of the five peers were randomly assigned two or three program participants, although authors did take into account requests from some peers to have two rather than three peers that they were supporting due to personal time limitations.	No matching, self-selecting - An individual from the group exercise class volunteered to be the peer