Background: Agriculture is one of the most hazardous industries in Minnesota and the United States. In rural Minnesota, adolescents are frequently employed in both agricultural and non-agricultural jobs and are injured at a higher rate than older workers. To address this issue, the Minnesota Department of Health previously developed and pilot tested an occupational health and safety curriculum targeted to rural Minnesota adolescents. The Work Safe Work Smart curriculum contains nine lessons developed to enhance adolescent knowledge, attitudes, and beliefs related to rural occupational health and safety. The specific goals of this study were to (1) evaluate the effectiveness of the Work Safe Work Smart curriculum in rural Minnesota high schools by measuring changes in attitudes and beliefs related to preventative behaviors based on behavior-change theory; (2) identify critical factors for incorporating the curriculum into existing school curricula; and (3) promote dissemination and utilization of the curriculum in rural schools. Methods: A group-randomized study design was used to evaluate the curriculum. Eligible schools were rural public high schools with 20 students in each grade. Using a stratified cluster design, schools were randomly selected from within four agricultural regions and three categories of school size. Participating schools within each region and size class were randomly assigned to the intervention or control conditions. The primary evaluation tool was a self completed student questionnaire that included demographic information; possible covariates (such as farm residency, work history); and components of behavior-change models such as knowledge, intention, perceived benefits, perceived barriers, perceived susceptibility, perceived severity and self-efficacy. A pre-test and two post-tests were used to evaluate outcomes. Following recruitment and teacher training, 18 intervention schools (N=2183) and 20 control schools (N=2568) agreed to participate in the evaluation. Baseline (pre-test) data was collected in the Fall of 2001, preceding curriculum implementation. Post-tests were administered in the Spring and Fall of 2002. Survey items were grouped a priori and summed into scores for seven outcome categories for analysis (knowledge, intent, benefits, barriers, susceptibility, severity, and self-efficacy). Statistical analysis was based on mixed linear models with adjustment for baseline (pre-test) values. Secondary analyses examined the curriculum impact by covariates of gender, race, ethnicity, academic level, farming experience, farm residence, work history, injury history, parental education, and thrill-seeking behaviors. Data from a previous non-randomized study were also analyzed. Results: All schools remained in the study through the first post-test, but one intervention and two control schools withdrew before the second post-test. Two of the intervention schools were not able to complete the curriculum by the first post-test. Students were exposed to the curriculum primarily through health classes (42%) and careers classes (40%). By Post-Test 1, adolescents exposed to the curriculum demonstrated a statistically significant change in three outcomes. Compared to control students, intervention students showed a greater awareness of their risk of workplace injuries (perceived susceptibility, p = 0.038), reported a greater insight of potential life altering workplace injuries (perceived severity, p 0.001), and an increased understanding of hazard recognition, labor laws, and workplace injury prevention strategies (increased knowledge, p = 0.004). By the second post-test, only one of the seven outcomes (perceived severity, p=0.025) remained statistically significant. Secondary analyses indicated that the effectiveness of the intervention was not consistent across various categories of measured covariates. For some outcomes, there was evidence of a greater intervention effect among girls, freshmen (9th graders), those with a parental education beyond high school, nonHispanics, and those with a reduced frequency of risky behaviors. There was little evidence that intervention effectiveness was associated with farm residence, previous work history, previous farm work, or previous work injury. Data from a previous non-randomized study of the curriculum supported the overall findings. Following completion of the post-tests, over 4,000 copies of the curriculum were distributed on CD-ROM and the curriculum (whole or in parts) was downloaded over 8,000 times from the Minnesota Department of Health web site. Conclusion: The Work Safe Work Smart curriculum was successfully implemented into a variety of existing school curricula in a sample of rural Minnesota high schools. Adolescents exposed to the curriculum demonstrated measurable changes in several outcomes that may be associated with beneficial behaviors in occupational safety and health.
Center for Occupational Health and Safety, Chronic Disease and Environmental Epidemiology Section, Health Promotion and Chronic Disease Division, Minnesota Department of Health, 85 East Seventh Place, PO Box 64882, St. Paul, Minnesota 55164-0882.