Dutta 2014

Methods	Random allocation with cross‐over Unblinded Study duration: 10 weeks Dropout: 1231 working hours data were missing Location: USA Recruitment: a word‐of‐mouth search was performed for finding interested companies to host the study and Caldrea Inc. volunteered. A recruitment presentation was made at an all‐employee meeting (n ˜ 50) and was followed a few days later by enrolment interviews.
Participants	Population: employees of Caldrea Inc. company, USA Demographics: average age: 40.4 years; out of 28 participants, 19 were female
Interventions	Duration of intervention: 4 weeks Intervention: sit‐stand desk Three different models of desks were used: Workfit‐S, a setup that attaches to the front of one’s existing desk that can hold the computer monitor, keyboard and mouse; Workfit‐A, a setup that is identical to Workfit‐S but attaches to the back of one’s existing desk; and Workfit‐D, a whole desk that is easily moved up and down. The Workfit‐A and S also came with an added work‐surface and all three types of desks came with anti‐fatigue floor mats for comfort during standing. Control: no sit‐stand desk
Outcomes	Outcome name, measurement time/tool (units of measurement) Sitting time, standing time, and light activity at work self‐reported and objectively assessed with accelerometer‐inclinometer Self‐reported energy and relaxation levels
Notes	James A. Levine has patents in accelerometer algorithms with Gruve Technologies Inc. but he did not access or analyse the raw the data from the Gruve device.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were randomly assigned to receive the intervention during period 1 or period 2, using a 1:1 allocation in 1 block of 35, using Microsoft Excel 2007.
Allocation concealment (selection bias)	High risk	Allocation concealment was not possible due to the nature of the intervention.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants and personnel was not possible due to the nature of intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	If we assume a person works for 40 hours per week, then for 28 participants the working hours will be 8960 hours for 8 weeks (4 weeks intervention and 4 weeks control period). However the study reported only 7,729 working hours based on accelerometer data.
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	There were no significant differences in age or BMI between interventions and control groups. Most of the participants were female.
Validity of outcome measure	Low risk	The accelerometer is a valid instrument for the measurement of sitting time.