Table 1 Method, content, and duration of the interviews per respondent group

Employee

individual interview

Instruction: "Let us suppose the OP just told you that you have an elevated CVD risk. He recommended you sign up for a lifestyle intervention and gave you the following brochure". Interviewer reads the brochure to the employee.

• Open question: "Would you sign up for the intervention? Why would you/wouldn’t you?"

• Statements: The interviewer reads statements from cue cards to the employee and asks whether the factor in question had a role in his decision on signing up for the intervention.

Occupational Physician

individual interview

Instruction: The interviewer gives a written description of the intervention and implementation plan to the OP.

Questions:

• What is your current approach to CVD risk management and the promotion of a healthy lifestyle among employees of the construction industry?

• Which changes does the implementation of the intervention Health under Construction imply for the way you work?

• How would you go about implementing those changes?

Medical Assistant

individual interview

Instruction: the interviewer gives a written description of the intervention and implementation plan to the medical assistant.

Questions:

• How do you currently go about performing a PME for employees in the construction industry?

• Which changes does the implementation of the intervention Health under Construction imply for the way you work?

• How would you go about implementing those changes?

Manager

individual interview

Instruction: the interviewer gives a written description of the intervention and implementation plan to the medical assistant.

Questions:

• What is the current approach of your OHS to CVD risk management and the promotion of a healthy lifestyle among employees in the construction industry?

• Which changes does the implementation of the intervention Health under Construction imply for the way this OHS works?

How would you go about implementing those changes?

Counselor

focus group

General questions to facilitate recall:

• How did you go about performing the counseling for Health under Construction?

• What were useful elements of the intervention?

Questions: The process evaluation during the trial of Health under Construction showed that counselors found it difficult to

1) schedule five to seven consultations within a period of six months,

2) apply the motivational interviewing technique

3) motivate participants to maintain the behavior change and to attend the counseling.

• How did you experience this aspect of the intervention?

• Which factors contributed to the problem?

• Which factors helped you to overcome this difficulty?