External validity of a generic safety climate scale for lone workers across different industries and companies

Purpose The goal of this study was to examine the external validity of a 12-item generic safety climate scale for lone workers in order to evaluate the appropriateness of generalized use of the scale in the measurement of safety climate across various lone work settings. External validity evidence was established by investigating the measurement equivalence (ME) across different industries and companies. Method Confirmatory factor analysis (CFA)-based and item response theory (IRT)-based perspectives were adopted to examine the ME of the generic safety climate scale for lone workers across 11 companies from the trucking, electrical utility, and cable television industries. Results Fairly strong evidence of ME was observed for both organization- and group-level generic safety climate sub-scales. Although significant invariance was observed in the item intercepts across the different lone work settings, absolute model fit indices remained satisfactory in the most robust step of CFA-based ME testing. IRT-based ME testing identified only one differentially functioning item from the organization-level generic safety climate sub-scale, but its impact was minimal and strong ME was supported. Implications The generic safety climate scale for lone workers reported good external validity and supported the presence of a common feature of safety climate among lone workers. The scale can be used as an effective safety evaluation tool in various lone work situations.