*2.2. Sampling and Recruitment*

Workplaces were identified by random stratified sampling based on the following variables: industrial sector, geographic region, and size. Study recruitment took place from 15 March 2011, to 27 August 2012, which began with the OLIP study's health and safety association partners making initial contact with organizations to solicit their interest. If an organization consented to take part in the study, the person most knowledgeable about health and safety at their organization completed an online English-language questionnaire. Respondents were also given the option to complete the questionnaire by mail or phone. Questionnaires were administered to each respondent in a random sequence. Three to ten follow-up e-mails or phone calls were sent to remind participants to complete questionnaires. The study was approved by the University of Toronto's research ethics board (protocol 25363).
