Context: Worksites represent important venues for health promotion. Development of psychometrically sound measures of worksite environments and policy supports for physical activity and healthy eating are needed for use in public health research and practice.
Objective: Assess the test-retest reliability of the Worksite and Energy Balance Survey (WEBS), a self-report instrument for assessing perceptions of worksite supports for physical activity and healthy eating.
Design: The WEBS included items adapted from existing surveys or new items on the basis of a review of the literature and expert review. Cognitive interviews among 12 individuals were used to test the clarity of items and further refine the instrument. A targeted random-digit-dial telephone survey was administered on 2 occasions to assess test-retest reliability (mean days between time periods = 8; minimum = 5; maximum = 14).
Setting: Five Missouri census tracts that varied by racial-ethnic composition and walkability.
Participants: Respondents included 104 employed adults (67% white, 64% women, mean age = 48.6 years). Sixty-three percent were employed at worksites with less than 100 employees, approximately one-third supervised other people, and the majority worked a regular daytime shift (75%).
Main outcome measures: Test-retest reliability was assessed using Spearman correlations for continuous variables, Cohen's κ statistics for nonordinal categorical variables, and 1-way random intraclass correlation coefficients for ordinal categorical variables.
Results: Test-retest coefficients ranged from 0.41 to 0.97, with 80% of items having reliability coefficients of more than 0.6. Items that assessed participation in or use of worksite programs/facilities tended to have lower reliability. Reliability of some items varied by gender, obesity status, and worksite size. Test-retest reliability and internal consistency for the 5 scales ranged from 0.84 to 0.94 and 0.63 to 0.84, respectively.
Conclusions: The WEBS items and scales exhibited sound test-retest reliability and may be useful for research and surveillance. Further evaluation is needed to document the validity of the WEBS and associations with energy balance outcomes.