Author(s): JUDICE, P., TENO, S.C., SILVA, H., Institution: UNIVERSIDADE LUSÓFONA, LISBON., Country: PORTUGAL, Abstract-ID: 284

INTRODUCTION:
Background: There is evidence on the effectiveness of sit-stand desk based interventions to reduce office workers’ sitting time (ST). Previously designed interventions have been relying on the contextual change (i.e., introducing sit-stand workstation in the workplace) coupled with frequent prompts throughout the intervention period, and in most cases kicked off with an initial psychoeducation session. Even though most sit-stand desk based interventions have shown good results, there is some heterogeneity between studies. The isolated impact of the psychoeducation session in boosting the results for this type of intervention has never been explored.
Aim: To examine changes in activPAL-derived outcomes from a 3-month intervention with a sit-stand workstation preceded by one psychoeducation session, in comparison to a control group that also used a sit-stand desk for 3 months but with the psychoeducation session being held 6 months before receiving the sit-stand desk.
METHODS:
Data comes from a larger 6-month intervention, in which the intervention group had a psychoeducation session, motivational prompts, and contextual modification by a sit-stand desk in the workplace, while the control group also had the same initial psychoeducation session but then continued to work as usual in a traditional sitting desk for 6 months. After this period, the control group used the sit-stand desk for 3 months. For these analyses we considered the available data from both the intervention and control groups at 3 months. Repeated measures ANOVA was used to examine differences between groups from baseline to 3 months.
RESULTS:
At baseline, there were no differences between groups for any of the demographic or activPAL-derived variables (p>0.05), except for standing time, favoring the intervention group (318 vs 221 min/day; p=0.033). A significant time*group interaction was found for ST (p=0.003), with the control group (N=10; 45.8±9.4 years) significantly reducing ST by 51 min/day, while the reduction in the intervention group (N=10; 48.5±5.7 years) of 44 min/day was non-significant. Regarding standing time, there was no time*group interaction, but while the intervention group significantly increased standing time by 47 min/day; p=0.022, the control group only increased this feature by 19 min/day (p>0.05). Finally, a significant time*group interaction was found for ST in bouts longer than 60 min (p=0.015), with the intervention group reducing 28 min/day, while the control group decreased prolonged bouts of sitting merely by 8 min day.
CONCLUSION:
Our results highlight that a 3-month sit-stand desk based intervention can reduce ST, regardless of the timing of the psychoeducation session. However, when the aim is to increase standing time and reduce ST at the expense of prolonged bouts, having a psychoeducation session right before the intervention, may potentiate the intervention.