Wolever 2012.

Methods	Randomized controlled trial, parallel group, 3 arms (only two arms used in this review, the yoga group was not analysed). Total study duration: 12 weeks. Study location: USA. Study setting: 2 sites within a single insurance corporation. Date of study: 2010
Participants	683 potential participants were recruited via email from a single national insurance corporation from two states (CA and CT) in USA for screening. Inclusion criteria: 16 or higher on 10‐item PSS Exclusion criteria: heart arrhythmia, pregnancy, heavy tobacco or nicotine use, heart rate medication, any major medical condition After screening, 239 eligible participants were randomised into yoga (N = 90, not analysed), mindfulness‐online (N = 52, 50 completed (96%)), mindfulness‐in‐person (N = 44, 32 completed 73%)), and wait‐list control (N = 53, not analysed). The demographics of the mindfulness groups, collectively, were: Mean age: 44.3 (SD = 9.4) Male: 22.9% White: 85.4% Married: 66.7% At least a college education: 75.0%
Interventions	Mindfulness at Work programme, 12 weeks (14 hours total) Within 12 weekly hour‐long classes, the programme taught mindfulness practices (each practice from 5 to 15 minutes) targeting work‐related stress, work‐life balances, and self‐care. An additional 2‐hour mindfulness practice intensive occurred at week 10. The in‐person group was taught in classes of around 20 participants each. The computer‐based group had the same teacher as the in‐person group, giving the same instructions, but via an online classroom with real‐time bi‐directional communication. Same assignments and homework.
Outcomes	Perceived Stress Scale (PSS) Follow‐up 2 weeks after the 12‐week intervention
Notes	Aetna, Inc. and eMindful funded the study. Mindfulness at Work is owned by eMindful and contracted for use by Aetna for delivery through eMindful. AK contacted the first author for additional information.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Personal communication with the first author: independent statisticians generated blocks of random numbers
Allocation concealment (selection bias)	Low risk	Personal communication with the first author: "Sealed envelopes were created with the allocation inside. As participants enrolled and went through baseline, they were given a study number. After collection of baseline data, randomisation sequences were disclosed to participants individually."
Incomplete outcome data (attrition bias) All outcomes	High risk	While a comparison of attrition was reported as not having any statistically significant differences in primary outcomes compared to completers, and a comparison of ITT and 'as‐completed' groups did not reveal significant differences in primary outcomes, the loss to follow‐up in the computer‐based group was 4% (2/52), and 27% (18/44) in the in‐person group. Thus, due to the statistically significant difference in the proportion lost to attrition in the two groups (P < 0.001), which did not occur in any other inter group comparisons of this study, and because one group had greater than 20% attrition, we assessed the risk of attrition bias as high.
Selective reporting (reporting bias)	Low risk	The study appeared to be free of any selective reporting. The main outcome of stress was measured and reported according to protocols provided by the author.
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding, Self‐reported outcome
Other bias	High risk	The study was funded by the software company that developed the intervention being tested.
Multiple intervention arms (reporting bias)	Low risk	While multiple arms of interventions were randomised in the study, one of the stated objectives of the study was to compare the online version of their stress management intervention to the in‐person version, thus, assessed as low risk of bias for selective reporting.
Treatment fidelity	Unclear risk	No evidence was available to support or refute that the interventions were delivered as planned.