Background
Conceptual model of social networks and PA
Pathways through which concepts in SNAP model influence PA
Methods/Design
Aims
Hypotheses
Participants
Randomization
Intervention
Theoretical Concepts | Intervention Procedures1
| Minimal Treatment Control | WalkLink | WalkLink+ |
---|---|---|---|---|
Social Functions
|
Educational materials
| X | X | X |
• Encouragement/prompt | -Receive same PA prescription. | |||
-Receive walking “tips of the week” once weekly. | ||||
Social Functions
|
Shape walking quantity and speed
| X | X | |
• Modeling | -Receive one-on-one in-person meeting. Program activities demonstrated and practiced with corrective feedback. | |||
• Resources/assistance | -Given pedometer, stopwatch, walking log, and program manual. | |||
• Behavioral monitoring | -Prompted once weekly to submit walking logs to research staff. | |||
-Self-monitor walking quantity and speed using walking log, pedometer, and stopwatch. | ||||
• Behavioral norms | -Walking quantity and speed compared to other program participants and past performance. | |||
• Behavioral refinement | -Given tailored weekly goals and graphical feedback to increase walking quantity and speed. | |||
• Encouragement, praise | ||||
Environment and Social Structure and Functions
|
Online WalkLink social network site
| X | ||
• Setting/resource access/proximity, number, homogeneity |
-Promoted as a local program and participants informed they were living in same neighborhood as other participants. | |||
• Network physical proximity | -Prompted to attend four “meet the group” walks led by project staff in central neighborhood locations; participants asked to introduce themselves/talk to each participant. | |||
• Virtual and in-person interaction modes | -Access to WalkLink Facebook site during, and at least 1 year after program. Site activities include: posting profile, inviting family/friends/coworkers to join site, posting and joining local walking and PA events,discussion board, status updates, posting photos, “friending” other participants; received emails from site. | |||
• Network centrality and transitivity | ||||
• Modeling/norms | ||||
• Encouragement, praise | ||||
• Resources, assistance, companionship | -Eligible for entry into drawings for gift cards contingent on posting or joining walking/activity events on WalkLink site. | |||
• Behavioral monitoring | ||||
Environment and Social Structure and Functions
|
Shape social network-building activities across in-person settings and online WalkLink site
| X | ||
• Behavioral monitoring | -Self-monitor number of walks taken with others, and in-person community-based and Facebook-based social networking activities completed each week using checklist (Figure 3); submit networking activities once weekly to research staff. | |||
• Setting/resource number, homogeneity | ||||
• Virtual and in-person interaction modes | ||||
• Network centrality and transitivity | ||||
• Behavioral norms | -Participation in social networking activities compared to other program participants and past performance. | |||
• Behavioral refinement | -Given tailored weekly goals and graphical feedback to increase social networking activities. | |||
• Encouragement, praise |
Measures
Theoretical Concepts | Measures | Pre | During | Post | 6-month follow-up |
---|---|---|---|---|---|
Built and Natural Physical Environment
|
Walkability (connectivity, density, mixed-use), Perceived Attributes
| ||||
X | |||||
• Walkscore [82] | X | ||||
• Neighborhood Environment Walkability Scale [83] | X | X | X | ||
PA Settings and Resources: Number, Attributes, Homogeneity
| |||||
• Convenient PA facilities questionnaire [84] | X | X | X | ||
• Home exercise equipment questionnaire [84] | X | X | X | ||
• Settings where PA was done (adapted scale) [85] | X | X | X | ||
Population Attributes
|
Population Number and Density
| ||||
• Census data | X | ||||
Population Individual Attributes
| |||||
• Background characteristics questionnaire | X | ||||
Population Homogeneity
| |||||
• Degree of similarity on selected characteristics between each participant and other participants by each recruitment cohort [86] | X | ||||
Interaction Mode
|
Use of Interaction Modes for Walking and Physical Activity
| ||||
• Self-reported use of different communication modes (online, phone, in-person) to organize walking and PA* | X | X | X | ||
• WalkLink+ group only: objective monitoring of frequency and types of activities conducted (e.g., posting walks, contributing to discussions) on online WalkLink site | X | X | X | ||
Access and Use of Interaction Modes in General
| |||||
• Self-reported ownership and use of cell phones to receive email* | X | ||||
• Self-reported use of Facebook, Twitter, and MySpace* | X | ||||
Social Network Centrality
|
In-Person Connections
| ||||
• Self-reported number of different companions for walking and PA* | X | X | X | ||
• Self-reported number of friends/family members participating in this program* | X | X | |||
Online Connections
| |||||
• WalkLink+ Group only: objective monitoring of number of “friends” on online WalkLink site | X | X | X | ||
Social Network Relational Attributes
|
Physical Proximity
| ||||
• Self-reported geographical proximity to existing walking and PA companions* | X | X | X | ||
Network Relationship Roles
| |||||
• Self-reported types of relationships (e.g., friend, family member) with existing walking and PA companions* | X | X | X | ||
Social Network Functions: Behavioral
|
Resources, Assistance, Companionship, Encouragement, Praise
| ||||
• Social support for walking and PA scales [87] | X | X | X | ||
• Participant actions to prompt walking and PA scale* | X | X | X | ||
Modeling/Norms
| |||||
• Modeling and social norms for walking and PA scale* | X | X | X | ||
Behavioral Monitoring and Refinement
| |||||
• Goal setting and planning for walking scales (adapted) [74] | X | X | X | ||
Social Network Functions: Perceived
|
Physiological Exertion
| ||||
• Borg rating of perceived exertion immediately after each walk [88] | X | ||||
Emotional States/Enjoyment
| |||||
• Rating of overall feeling/emotions immediately after each walk [14] | X | ||||
• Walking enjoyment (adapted scale) [89] | X | X | X | ||
Perceived Benefits and Costs
| |||||
X | X | X | |||
Physical Activity
|
Sedentary Behavior, and Light, Moderate, and Vigorous PA
| ||||
X | X | X | |||
Walking Activity
| |||||
X | |||||
• National Health Interview Survey (2 items) [94] | X | X | X | ||
PA in Different Life Domains, Sedentary Behavior
| |||||
• International PA Questionnaire, long version [95] | X | X | X | ||
PA Modes (different types of PA)
| |||||
• Aerobics Center Longitudinal PA Questionnaire [96] | X | X | X | ||
Health Outcomes
|
Aerobic Fitness
| ||||
• Submaximal treadmill test: submaximal heart rate (measured by Polar heart rate monitor) during test [97] | X | X | X | ||
• Submaximal treadmill test: estimated VO2max [97] | X | X | X | ||
Vitals
| |||||
• Pulse: calibrated hospital-grade Welch Allyn device [98] | X | X | X | ||
• Blood pressure: calibrated hospital-grade Welch Allyn device [98] | X | X | X | ||
Body Composition
| |||||
• Body mass index: Physician’s balance beam scale (model Detecto 439) and calibrated Seca 242 digital stadiometer [97] | X | X | X | ||
• Waist circumference: Gulick II tape measure [97] | X | X | X | ||
Sleep Quantity and Quality
| |||||
• Pittsburgh Sleep Quality Index [99] | X | X | X | ||
• Exposure to ambient noise during sleep scale* | X | X | X | ||
Intervention Fidelity
|
Participation[100] | ||||
• Return rate for weekly walking logs | X | ||||
• Attendance rate at program-organized walks for WalkLink+ group | X | ||||
• Activities on online social networking site for WalkLink+ group | X | X | X | ||
Intervention Receipt and Satisfaction[100] | |||||
• Program evaluation survey: qualitative and quantitative assessment* | X | ||||
Change in Theoretical Mediators
| |||||
• Degree to which theoretical mediators (listed above) changed in hypothesized direction for each of the intervention groups | X | X | X | X | |
Intervention Delivery and Quality Control
| |||||
• Program records, weekly meetings, staff training, walking feedback double-checked each week and 10% of feedback reviewed by PI, double-verification of manually entered data, participants recontacted for missing data, multiple sources of contact information obtained for each participant | X |