Work site-based cancer prevention: primary results from the Working Well Trial

Am J Public Health. 1996 Jul;86(7):939-47. doi: 10.2105/ajph.86.7.939.


Objectives: 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.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cross-Sectional Studies
  • Diet
  • Diet Surveys
  • Female
  • Follow-Up Studies
  • Health Behavior*
  • Health Education / organization & administration*
  • Health Services Research
  • Humans
  • Male
  • Neoplasms / prevention & control*
  • Occupational Health Services / organization & administration*
  • Regression Analysis
  • Smoking Prevention
  • United States