Protocol for a cluster randomized controlled trial to study the effectiveness of an obesity and diabetes intervention (PASOS) in an immigrant farmworker population

Background: Studies have shown that the prevalence of overweight, obesity and diabetes are higher in the largely Hispanic, immigrant farmworker population in California. Though to date, few interventional studies have focused on these issues in this at-risk population. The objective of this paper is to describe the study design of a cluster randomized controlled trial aimed at evaluating the effectiveness of an obesity and diabetes work place intervention in an immigrant farm worker population. Methods: PASOS is an obesity and diabetes intervention program that will be implemented on ranches where immigrant farmworkers spend a considerable amount of time each day. This cluster randomized controlled study will enroll approximately 600 farmworkers. Using a uniform distribution for random number generation, ranches are randomized using a 1:1 ratio as either control or intervention. Baseline data will be taken from eligible participants and analyzed against data collected at the post-intervention, 6-month, 1-year, and 1.5-year follow-ups. The enrollment period is 1.5 years. Discussion: Few studies have been conducted that aim to evaluate the effectiveness of a worksite intervention for obesity and diabetes prevention in a largely Hispanic, farmworker population. This study has been tailored to this population in order to enhance the feasibility of implementation and retention. If successful in reducing obesity and increasing healthy lifestyle choices to reduce diabetes, this study design can be implemented on a larger scale.