Table 4 Changes made to protocol based on pilot results

 A conceptual framework was developed based on the literature. Participants made numerous enlightening comments regarding barriers to walking outdoors and personal changes they noted during the study in qualitative interviews.

The conceptual framework was enhanced based on qualitative findings

 During qualitative interviews, participants suggested additional recruitment strategies.

Public service announcements and advertisements on “oldies” radio stations will be a part of the recruitment approach.

 PAR-Q+ was used as a screen for physical activity readiness

The Get Active Questionnaire will be used, as the PAR-Q+ has since been replaced by the Get Active Questionnaire

 A couple wanted to be in the same group.

Because participation as a couple may be a facilitator of outdoor walking activity (primary outcome), participants will be stratified as singlets or dyads prior to randomization

 Had planned to stratify participants by gait speed (< 0.8 m/s vs ≥ 0.8 m/s); however, no participants walked slower than 0.8 m/s.

Will not stratify by gait speed.

 One participant did not meet minimum wear time for activity monitor and GPS.

Participants will be reminded verbally when receiving the activity monitor and in writing on an activity log that they need to wear the monitor morning to night and for a minimum of 10 h per day. IF they do not achieve a min 4 days of wear time, they will be asked to wear the monitor on additional days.

 Participants had very low activity by activity monitors.

Analysis of activity monitor and GPS data will define bouts as “Lifestyle 5 min” and will also present daily sporadic minutes of Lifestyle MVPA.

Analysis of cadence will also be used to better describe continuous purposeful walking

 Time intensive to match GPS and activity bouts. Some bouts difficult to determine if indoors or outdoors.

Introduce an outdoor walking time log, to assist with identification and analysis of outdoor activity.

 Did not objectively quantify extent and intensity of walking activity during the outdoor walking sessions (process indicator).

GO-OUT participants will be asked to wear the activity monitor/GPS during two outdoor walking group sessions to evaluate extent and intensity of walking activity and compare across sites.

 Scores on the Berg Balance Scale and Geriatric Depression Scale were similar across study evaluations.

The Berg Balance Scale and Geriatric Depression Scale will not be used.

The Berg Balance Scale will be replaced with the Mini-BESTest [73], which may be more sensitive to change resulting from the GO-OUT intervention. The Emotional Well Being subscale of the RAND-36 will substitute for the GDS as a measure of emotional health.

 One participant suggested that for a future study, regular phone follow-up asking how much they were walking would be beneficial for the workshop group.

The workshop group will have weekly phone reminders to re-iterate information learned in the workshop and to encourage outdoor walking.

 Duration of GO-OUT intervention was 9 weeks due to the start time of project.

GO-OUT program will be 12 weeks.

 For personal safety, GO-OUT participants did not like one park with isolated parking and forested walking trails with few other walkers.

Ensure that parks used for GO-OUT do not have isolated parking areas and have numerous walkers in the area.