*2.3. Procedure*

The research team visited two Australian mining sites and a corresponding residential mine village. Due to safety regulations the team was prohibited from entering some work site areas. Company managers nominated working units with the goal of obtaining a representative sample of employees. In these work units, participant information sheets were displayed in common gathering areas and announcements were made by mangers at daily work group meetings. All employees of the selected work units who were sighted by the researchers during the data collection period were invited by the researchers to participate in the health survey. The survey was provided in hard copy (on paper) and once complete returned to the research team. All data were entered and analysed in IBM SPSS version 21 (IBM, Armonk, NY, USA). Participants included a mixture of operational, managerial, and administrative roles. Managers were not informed of which employees participated in the research.

#### *2.4. Measures*

Demographic and employment characteristic measures replicated government survey and corporate health survey items [4,24]. Consistent with previous research [4], stress was measured by the item "How much of the time in the past four weeks did you feel stressed while at work?" Response options included: none of the time; a little of the time; some of the time; a good bit of the time; most of the time; and all of the time. Participants were classified as stressed if they selected: some of the time; a good bit of the time; most of the time; or all of the time. Participants were classified as low risk of stress and excluded from stress analyses if they responded: none of the time; or a little of the time.

Consistent with previous research measuring miners' readiness to change healthy behaviours using the Stages of Change Model [25], participants were asked to select one of five statements in response to the following question. 'How would you describe your approach to stress management?' Response option statements were amended from previously published nutrition and physical activity focused statements [25] to focus on stress management and were based on the traditional Stages of Change Model of behaviour change stage descriptions [26]. More specifically, stress management stage of change was measured by the selection of one of the following statements: pre-contemplative "As far as I'm concerned my stress management habits don't need changing"; contemplative "I'm seriously intending to better manage my stress in the next 6 months"; preparation "I have definite plans to better manage my stress in the next month"; action "I am doing something to better manage my stress"; and maintenance "I took action more than six months ago to better manage my stress and I'm working hard to maintain this change".

The Worker Productivity and Activity Impairment—General Health (WPAI:GH) questionnaire [27] items including hours worked, work absenteeism (i.e., work time missed due to health), and work presenteeism (i.e., impairment while working due to health) were replicated with minor amendments. Consistent with previous research using a shift work mining sample [4], the original seven-day measurement period was extended to a four-week period to minimize the impact of acute illnesses and shift work rosters to read, "During the past four weeks, how many days did you miss from work because of your health problems?"

Based on established World Health Organization and government survey items [24,28] the following outcome item "Would you like assistance with stress management?" was asked in the workplace health program survey section to measure employees' preference for assistance.
