Kress 2014

Methods	Non‐random allocation Study duration: 6 months Drop outs: 47% Location: United States Recruitment: participants were contacted by email with an invitation to participate in the study
Participants	Population: call centre workers in a company (healthways) in USA. Healthways Inc., a well‐being improvement company with headquarters in Franklin, Tennessee, has multiple call centres in which their Health Coaches, Clinicians (Nurses and Dieticians), and Customer Service Representatives work. Intervention: sit‐stand desks (45 participants0, standing desks(46 participants) Control: seated (47 participants) Demographics: mean age in years: sit‐stand 34.8 (SD 11.5), standing 28.9 (6.8), seated 35 (SD 13.2) % female participants: sit‐stand 71%, standing 59%, seated 70% BMI: sit‐stand 29 (SD 9.13), standing 26.8 (SD 5.5), seated 27.8 (SD 5.7)
Interventions	Duration of intervention: 6 months Sit‐stand desk vs. standing desk
Outcomes	Outcome name, measurement time/tool (units of measurement) Self reported changes in sitting/standing (minutes/ workday) measured at 6 months Energy expenditure (calories/minute) Participants experiences with the new workstation at 6 months
Notes	Data for seated group not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Likely not random and it may be that people swapped desks because of open design of call centre.
Allocation concealment (selection bias)	High risk	Assignment to the workstation type was dependent on Healthways, and it made assignments as random as possible.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	High dropout (47% attrition)
Selective reporting (reporting bias)	Low risk	All outcomes mentioned in the methods section were reported. The study protocol was not available.
Baseline comparability/ imbalance	Low risk	Mean age of participants was higher for sit‐desk (control) group. Both groups were comparable at baseline for gender and BMI.
Validity of outcome measure	Unclear risk	The armband accelerometer (SenseWear model) is a valid instrument for assessing physical activity and sedentary behaviour