Sample
This study was conducted in two university buildings in Universitas Gadjah Mada, Yogyakarta, Indonesia. They were located 260 m apart in two different faculties in the health science cluster. Employees and students rarely moved from one building to another, which could minimise the risk of contamination bias. In both faculties, a health promotion initiative called the Health-Promoting University (HPU) has been running since July 2019. The same team supervised health promotion programs at the two sites. They targeted the same fields of intervention, including health literacy, physical activity, nutrition, mental health, zero tolerance for smoking, alcohol consumption, and illicit drug use, zero tolerance for violence, bullying, and sexual harassment, and safe buildings and healthy environments.In choosing the intervention and control buildings, the following characteristics were sought: (1) Two buildings with an almost similar number of occupants, (2) Two buildings with almost similar staircase and elevator design and placement, as well as the numbers of the stories (Characteristics of the buildings and posters.