Discussion
We described the process of designing the stair-use intervention and evaluating the intervention using the RE-AIM framework (The 6.7% increase in stair climbing in our study was higher than a previous systematic review reported, which showed a median increase of 0.8% with a motivational sign only (Our study also found that employees easily adopted portable stair posters. This sign might solve overcoming adoption barriers reported by a previous study (Our study had several strengths. It employed a controlled design with two identical buildings and objective monitoring with less burden of observers, less observer bias, and less contamination bias. In addition, we also controlled total visitors as a confounder (