摘要：Objectives. We examined the efficacy of a cancer prevention intervention designed to improve health behaviors among working-class, multiethnic populations employed in small manufacturing businesses. Methods. Worksites were randomly assigned to an intervention or minimal-intervention control condition. The intervention targeted fruit and vegetable consumption, red meat consumption, multivitamin use, and physical activity. Results. Employees in the intervention group showed greater improvements for every outcome compared with employees in the control group. Differences in improvement were statistically significant for multivitamin use and physical activity. Intervention effects were larger among workers than among managers for fruit and vegetable consumption and for physical activity. Conclusions. The social-context model holds promise for reducing disparities in health behaviors. Further research is needed to improve the effectiveness of the intervention. Current epidemiological evidence links dietary patterns and physical inactivity to a wide range of cancers and other chronic diseases. 1 – 6 These risk-related behaviors are disproportionately concentrated among individuals of lower socioeconomic position and among certain racial and ethnic minorities. 7 – 9 Unfortunately, intervention approaches have not been designed for or sufficiently tested among working-class, ethnically diverse populations. 10 – 12 Within our increasingly multi-ethnic society, a particular need exists for effective cancer prevention interventions that can be implemented across ethnic groups. 13 In workplace settings, for example, individuals from many different ethnic groups may work alongside one another, and although they may not share a common cultural background, they likely share the day-to-day realities of a working-class social position. We report the results of a study of a worksite cancer prevention intervention to improve the dietary and physical-activity patterns of working-class individuals across multiple ethnic groups. The Healthy Directions–Small Business Study was part of the Harvard Cancer Prevention Program Project, which developed and tested a common behavioral intervention model that could target multiple risk-related behaviors in a working-class, multiethnic population. The project consisted of interventions conducted through small businesses 14 and through health centers 15 and a policy model to estimate the potential population-based impact of the interventions. The interventions were based on a social-context framework 13 that describes pathways by which sociodemographic characteristic, such as income, 11 , 16 race/ethnicity, 17 and acculturation, 18 – 21 may influence health behaviors. The interventions were designed to target selected social-context factors that influence behavior and that are amenable to change (e.g., social norms). The interventions were designed to be responsive to factors that could not be altered by the intervention but that are important determinants of behavior (e.g., individual income). 13 , 22 One example of social context is on-the-job exposures that workers face. In previous research, we found that blue-collar smokers employed at worksites receiving an intervention integrating health promotion and occupational health and safety were twice as likely to quit smoking as blue-collar workers at worksites receiving health promotion programming alone. 23 We report on the efficacy of Healthy Directions–Small Business. These interventions were intended to reduce red meat consumption, 24 – 30 increase physical activity, 9 , 31 increase fruit and vegetable consumption, 24 and increase multivitamin use 32 , 33 among a working-class, multiethnic population of employees. The interventions were based on the assumptions that population characteristics such as occupational status, educational level, and ethnicity are not obstacles to behavior change and that it is necessary to understand and address the social-context factors associated with these characteristics. Specifically, the analyses presented here tested the following hypotheses: (1) persons employed at worksites randomly assigned to the intervention condition are significantly more likely to change targeted health behaviors than persons employed at worksites randomly assigned to the control condition; (2) the intervention is at least as effective in changing targeted health behaviors among the following groups: workers compared with managers, the less-educated compared with more-educated persons, and persons near or below the federal poverty level compared with those above the level; (3) the intervention is at least as effective in changing targeted health behaviors among Blacks, Asians, and Hispanics compared with non-Hispanic Whites, and among immigrants and first-generation Americans compared with persons whose parents were born in the United States.
