Maher 2017.

Study characteristics
Methods	Study design: Cluster‐randomised controlled trial Study grouping: Intervention to reduce sedentary behaviour and control group (intervention to reduce social isolation) Assessment: Weekday and weekend day sedentary behaviour was assessed using a 9‐item domain‐specific measure of behaviour. Sedentary behaviour was measured on day 7 (prior to the delivery of the sedentary behaviour content in the intervention group or after the delivery of the social isolation content in the comparison group) and on day 14 in both groups. Operational definition of sedentary time: Self‐reported sitting time in different behaviour Randomisation method: Cluster randomisation was used to reduce the threat of contamination within sites. Randomisation was stratified based on senior centre size (large centres had ≥ 30 regular attendees, small centres had < 30) using data from the county’s Office of Aging. A computer‐generated allocation sequence yielded 1 large and 2 small senior centres in the intervention group and 1 large and 1 small senior centre in the comparison group.
Participants	Baseline characteristics Overall Age: 76.9 (9.2) years Gender: 9.3% male Race: 93% white BMI: 29.7 (7.1) kg/m2 N = 42 (25 intervention) Inclusion criteria: Participants at senior centres Exclusion criteria: Diagnosed by a physician as having dementia or Alzheimer's disease. Injuries or illnesses that precluded standing or walking
Interventions	2‐week intervention involving 3, 1.5‐hour meetings for each group. Content in both groups involved watching video segments and participating in group discussions. In the intervention group, the content of the video and discussion focused on creating awareness about sedentary behaviour and associated risks, developing an action plan for reduction of sedentary behaviour and personal goals, tasks involving the participants comparing their sedentary time to peer and normative values, and tasks to enhance self‐efficacy. In addition, participants were educated on the benefits associated with displacing sedentary time with light‐intensity physical activity (e.g. standing, slow walking), such as decreased risk of premature death and cardiovascular disease and maintenance of physical and cognitive functioning. Participants were engaged in discussing their progress or barriers in achieving these goals; however, participants’ goal completion was not formally tracked. 2 target behavioural goals were identified: (1) stand or move for at last 10 min each waking hour or (2) limit sedentary behaviour to less than 8 waking hours/day over the course of the next week. Video segments and discussions in the comparison group focused on (1) defining social isolation, (2) assessing individuals’ social isolation via self‐report measure, (3) reviewing normative levels of social connectivity, (4) reviewing evidence of the consequences associated with social isolation as well as benefits associated with social engagement, (5) developing action plans to increase or improve social connectivity, and (6) establishing target goals.
Outcomes	Primary outcomes Sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better TV time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Computer sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Reading sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Socialising sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Hobbies sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Paperwork sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Eating sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better Other sedentary time (subjective) Outcome type: Continuous outcome Unit of measure: min/week Direction: Lower is better
Identification	Sponsorship source: Penn State CTSI Grant from the National Center for Advancing Translational Sciences, National Institutes of Health Country: USA Setting: Senior centres Comments: This is an RCT (with cluster randomisation) N = 42 of an intervention based on 3 workshops over 2 weeks. Assessment via subjective measure. Reports a decrease of SB of 837.8 min/week Author's name: Jaclyn P Maher Institution: The Pennsylvania State University Email: jmaher@usc.edu Address: The Pennsylvania University Park, PA, USA
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated allocation sequence
Allocation concealment (selection bias)	Low risk	Computer‐generated allocation sequence and cluster randomisation
Blinding of participants and personnel (performance bias) All outcomes	High risk	The same interventionist delivered the programme in the intervention (reducing sedentary behaviour) and the control group (reducing social isolation).
Blinding of outcome assessment (detection bias) All outcomes	High risk	Self‐reported measures, and nothing specifically reported about blinding of assessors
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data fully reported, little attrition, and all participants were included in the analysis.
Selective reporting (reporting bias)	Low risk	All outcomes listed in the methods section were presented in the results section.
Other bias	Low risk	None
Recruitment bias (cluster RCT only)	Low risk	Computer‐generated allocation sequence
Baseline imbalance (ClusterRCT only)	Unclear risk	No information reported about baseline characteristics per clusters or condition.
Loss of clusters (ClusterRCT only)	Low risk	No loss of clusters
Incorrect analysis (ClusterRCT only)	Low risk	Analysis adjusted for clustering.
Comparability with individually randomized trials(Cluster RCT only)	Low risk	Cluster randomisation was used to reduce the threat of contamination within sites.