title: Work site-based cancer prevention: primary results from the Working Well Trial.
abstract: OBJECTIVE
  This paper presents the behavioral results of the Working Well Trial, the largest US work site cancer prevention and control trial to date.
  
  
  METHODS
  The Working Well Trial used a randomized, matched-pair evaluation design, with the work site as the unit of assignment and analysis. The study was conducted in 111 work sites (n = 28,000 workers). The effects of the intervention were evaluated by comparing changes in intervention and control work sites, as measured in cross-sectional surveys at baseline and follow-up. The 2-year intervention targeted both individuals and the work-site environment.
  
  
  RESULTS
  There occurred a net reduction in the percentage of energy obtained from fat consumption of 0.37 percentage points (P = .033), a net increase in fiber densities of 0.13 g/1000 kcal (P = .056), and an average increase in fruit and vegetable intake of 0.18 servings per day (P = .0001). Changes in tobacco use were in the desired direction but were not significant.
  
  
  CONCLUSIONS
  Significant but small differences were observed for nutrition. Positive trends, but no significant results, were observed in trial-wide smoking outcomes. The observed net differences were small owing to the substantial secular changes in target behaviors.
authors.affiliation: Division of Cancer Epidemiology and Control, Boston, MA 02115, USA.
authors.forename: G
authors.initials: G
authors.lastname: Sorensen
authors.forename: B
authors.initials: B
authors.lastname: Thompson
authors.forename: K
authors.initials: K
authors.lastname: Glanz
authors.forename: Z
authors.initials: Z
authors.lastname: Feng
authors.forename: S
authors.initials: S
authors.lastname: Kinne
authors.forename: C
authors.initials: C
authors.lastname: DiClemente
authors.forename: K
authors.initials: K
authors.lastname: Emmons
authors.forename: J
authors.initials: J
authors.lastname: Heimendinger
authors.forename: C
authors.initials: C
authors.lastname: Probart
authors.forename: E
authors.initials: E
authors.lastname: Lichtenstein
mesh_terms: D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D005260:Female; D005500:Follow-Up Studies; D015438:Health Behavior; D006266:Health Education / Q000458:organization & administration*; D006302:Health Services Research; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000517:prevention & control*; D009786:Occupational Health Services / Q000458:organization & administration*; D012044:Regression Analysis; D000074606:Smoking Prevention; D014481:United States