3.2.1. Pain and Injury

Hypothesis 1a tested differences in pain incidence between intervention and control group workers. Model results revealed no significant differences at FU1 in the unadjusted model. However, after adjusting for covariates, in addition to the matched pairs, there was approximately 42% reduction in risk of having new pain or injury compared to the control sites (*p* = 0.012) (Table 3). While the magnitude of this risk reduction was maintained at FU2 there were fewer participants and an increase in variability that made this reduction not statistically significant. Thus, hypothesis 1a was partially supported at FU1.

**Table 3.** Effects of ARM intervention on Pain and Injury at 1-month and 6-months post-intervention while adjusting for baseline level of outcome variable.


CI = confidence intervals; OR = odds ratio. Results from logistic regression models with cluster robust standard errors to account for individual clustering within worksites (\*\* *p* < 0.05); <sup>1</sup> Adjusted model with fixed effects for matched pairs and for age, race, and job title. <sup>2</sup> New injury or pain reported by the worker on FU1 /FU2 survey since baseline survey.
