Background
The etiology of obesity is believed to be multi-factorial, including genetic, metabolic, behavioral, psycho-social, and environmental influences. Individual behaviors that directly affect energy balance include diet and physical activity (PA), which are influenced by larger psycho-social, environmental, organizational, and policy factors. If the factors responsible for physical inactivity and obesity at multiple levels can be better understood, we can identify more appropriate targets for dissemination and implementation. Because many employed adults spend at least half of their waking hours at work, worksites are excellent venues for health promotion. Due to rising costs of healthcare associated with obesity-related illness and disability, there is interest among employers in offering programs or benefits to assist employees in making healthful decisions. A particularly promising type of worksite health promotion strategy involves environmental and policy changes that may assist employees in making healthful choices at work (e.g., easy access to stairways, on-site exercise facilities, time or breaks for PA during the work day).

Objectives
The overall goal of this project is to understand how environments and policies where employed adults work are associated with energy balance. Here we examine whether specific types of worksite supports for PA are predictive of total and domain-specific PA.

Methods
Participants were from the Supports at Home and Work for Maintaining Energy Balance (SHOW-ME) study, a cross-sectional study to understand environmental and worksite policy influences on employees’ obesity status. Census tracts in four Missouri metropolitan areas (St. Louis, Kansas City, Springfield, and Columbia) were used for sampling. Between 2012 and 2013, 2,015 participants were recruited who met each of the following criteria: between the age of 21 and 65 years; employed outside of the home at one primary location; employed for 20 or more hours per week at one site with at least five employees; not pregnant; and no physical limitation to prevent walking or bicycling in the past week. Recruited participants completed a telephone-based survey. The survey instrument was developed using existing self-reported and environmental assessment instruments and input from a Questionnaire Advisory Panel. Worksite supports for PA included 18 unique items (e.g., ‘Does your workplace offer…’ ‘Incentives to use public transit, such as free or reduced transit pass,’ ‘Flexible time for PA during the work day’) as well as specific usage questions for 14 of the 18 items (e.g., ‘Have you used X in the past two months?’). PA and PA sub-domains (travel, work, and leisure) were measured using the International Physical Activity Questionnaire long form.  Analyses include unadjusted and adjusted odds of meeting domain-specific and total PA CDC recommendations (150 minutes per week), provided access and use of the 32 worksite support questions. Analyses adjusted for race, gender, age, income, employer size, self-reported health, obesity, and hours worked per week. Limited stratified results have been completed. Cumulative results (e.g., access and use to incentives to bike/walk to work AND access to a shower) are forthcoming.

Results
Access to five of 18 worksite supports for PA were significantly associated with increased odds of meeting the CDC’s recommended 150 minutes of moderate and vigorous PA. These were access to bike storage, flextime for PA, PA breaks during meetings, incentives to bike/walk to work, and maps or signs of worksite walking routes. Nine of 14 use of PA supports were associated with significant odds of meeting PA recommendations, including use of bike storage, shower at work, and outdoor exercise facilities. Of specific interest was the worksite supports associated with travel-domain PA. In unadjusted analyses, access to bike storage was associated with a 1.31 (95% CI: 1.03, 1.65) increase in odds of obtaining 150 minutes of PA during travel alone. Using bike storage was associated with a 4.40 (2.75, 7.02) increase in odds of meeting 150 minutes of PA. After adjustment the odds of obtaining 150 minutes of travel PA were only reduced to 4.32 (2.48, 7.52). For age groups there was a stepped progression in odds of meeting 150 minutes of travel PA. Odds ratios for meeting 150 minutes of travel PA were 4.06, 4.68, and 8.14, respectively for employees under the age of 45, 45-54, and older than 55 years. Each result was significant at p<0.05.

Conclusions
Access to and use of specific worksite policies and supports for PA increase the likelihood of employees meeting the CDC’s recommendation of 150 minutes of PA per week. The use of supports had greater associations with PA than mere access to supports, suggesting future research and intervention efforts should be primed to move from awareness of supports for PA to regular use of the supports.

Implications
Worksite wellness plans are on the rise across the US with worksites eager for evidence-based supports for increasing PA and reducing sedentary time. Our team is working to package results such that worksites can be informed of likely benefits associated with 18 unique supports as well as costs of specific supports.

Support / Funding Source
U54 CA155496-01 (Colditz, Center PI; Hipp, Project PI) NCI/NIH.  ‘A multilevel approach to energy balance and cancer across the life course: worksite policies and neighborhood influences on obesity and cancer risk.’