Promoting walking among office employees - evaluation of a randomized controlled intervention with pedometers and e-mail messages

Background: The purpose of the study was to evaluate a 6-month intervention to promote office-employees' walking with pedometers and e-mail messages. Methods: Participants were recruited by 10 occupational health care units (OHC) from 20 worksites with 2,230 employees. Voluntary and insufficiently physically active employees (N=241) were randomized to a pedometer (STEP, N=123) and a comparison group (COMP, N=118). STEP included one group meeting, log-monitored pedometer-use and six e-mail messages from OHC. COMP participated in data collection. Reach, effectiveness, adoption, implementation, maintenance (RE-AIM) and costs were assessed with questionnaires (0, 2, 6, 12 months), process evaluation and interviews (12 months). Results: The intervention reached 29% (N=646) of employees in terms of participation willingness. Logistic regression showed that the proportion of walkers tended to increase more in STEP than in COMP at 2 months in "walking for transportation" (Odds ratio 2.12, 95% CI 0.94 to 4.81) and at 6 months in "walking for leisure" (1.86, 95% CI 0.94 to 3.69). Linear model revealed a modest increase in the mean duration of "walking stairs" at 2 and 6 months (Geometric mean ratio 1.26, 95% CI 0.98 to 1.61; 1.27, 0.98 to 1.64). Adoption and implementation succeeded as intended. At 12 months, some traces of the intervention were sustained in 15 worksites, and a slightly higher number of walkers in STEP in comparison with COMP was observed in "walking stairs" (OR 2.24, 95% CI 0.94 to 5.31) and in "walking for leisure" (2.07, 95% CI 0.99 to 4.34). The direct costs of the intervention were 43 Euros per participant. Conclusions: The findings indicate only modest impact on some indicators of walking. Future studies should invest in reaching the employees, minimizing attrition rate and using objective walking assessment.