Taking the stairs

The epidemiologist Adrian Bauman pooled every stair-promotion study published since 1980, 50 of them with 57 separate estimates, and asked when the evidence had become sufficient. After a motivational sign, people were 52% more likely to take the stairs, at an adjusted odds ratio of 1.52 with a confidence interval of 1.37 to 1.70.

Median stair use before the signs was 8.1% and the median absolute increase 2.2 percentage points. Bauman’s incremental analysis puts the point at which the evidence became sufficient at 2006, and the paper asks researchers to stop running short-term small-scale sign studies and to test whether any of it scales.

The behavioural scientist Mathias Krisam mounted humorous slogans and graphics at one staircase in the Berlin Zoologischer Garten station for four weeks in autumn 2019, and counted a second staircase to the same platform as a control. Counts were taken mornings and evenings on two weekdays before, during and after. The odds of taking the stairs rather than the escalator rose to 1.43 during the campaign and stayed at 1.43 after it, both at p below 0.0001, which the authors convert to roughly 1,200 more people a day.

The public health researcher Intan Suhana Munira Mat Azmi went the other way, dropping the sample to eight people in each arm and following what happens in the blood. For eight weeks the intervention group climbed and descended four floors, eight times a day, prompted by their own computers, averaging 121 floors a week. Fasting blood glucose, total cholesterol and LDL all came down significantly, and the participants said afterwards that the interruption was tolerable. 8 people per arm is a feasibility study, and the paper presents it as one.

The architectural engineer Janan Ali and Faris Mustafa surveyed 240 employees in seven Erbil office buildings and measured the buildings themselves with space syntax software. The inclination to use the stairs was 1.24 and the lift 1.46. Satisfaction with how the stairs were designed was high, above 3.5, and had no significant association with how often anyone used them. What did correlate was the configuration of the building: connectivity, accessibility and visibility, and whether anything worth walking to was on the other floors.

The psychologist Hui-Ju Wu randomly showed 140 people images of natural or urban landscapes and then gave them a pedometer to return. Those who had seen nature chose the more distant return point and walked further. The mediator was temporal discounting: nature made the later, larger benefit weigh more against the nearer, smaller one.

Bauman’s is the only pooled estimate. Krisam counted people at a station without knowing anything about them, Mat Azmi worked with 16 in total, and Ali and Wu both measured intention or a proxy rather than months of behaviour.