2.3.1. Independent Variables: Workplace Demographic Characteristics

The independent variables used in the analysis were workplace demographic characteristics chosen a priori from the available literature as they were found to be linked to the co-occurrence of OHS and wellness activities. The following variables were examined, workplace size (four categories; small and without a Joint Health and Safety Committee, JHSC (reference category)), union status (unionized, non-unionized (reference category), don't know), industry sector (eight sectors; manufacturing sector (reference category)). Workplace culture factors previously found to be associated with OHS and wellness implementation [19,23] were examined using a measure of workplace health and safety leadership (lowest = 1 (reference category), highest = 4), and a measure of people-oriented culture (lowest = 1 (reference category), highest = 4) (Supplementary Table S1).

Union status (i.e., at least part of the workforce is represented by a union) was self-reported in the OLIP questionnaire. Questionnaire responses were linked to corresponding 2009 WSIB administrative records to obtain additional information on a workplace's industry sector classification. Workplace size was self-reported and categorized according to Statistics Canada classifications [24] as follows, small workplaces had 1 to 99 employees, medium workplaces had 100 to 499 employees, and large workplaces had ≥500 employees. Workplace size was a proxy of OHS infrastructure and accordingly, small workplaces were further classified by whether they reported having a JHSC (consists of labor and management representatives regularly meet to deal with health and safety issues). This categorization was based on the mandatory Ontario labor requirement that workplaces with >20 employees must have a JHSC. An organization's leadership support and culture were examined using two subscales selected a priori from the Organizational Policies and Practices questionnaire [25,26]: Health and Safety Leadership (six items) and People-Oriented Culture (four items). Participants rated the extent their organization achieved these subscales on a five-point scale from 0% (never) to 100% (always). Each subscale item was averaged to a score ranging from 0 (low) to 4 (high).
