Eisen 2008.

Methods	Randomised controlled trial with 3 arms (in‐person intervention, computer‐based intervention, and wait‐list control). The wait‐list control was not analysed. Total study duration: 8 months. Study location: USA. Study setting: 3 manufacturing sites within a single corporation. Date of study: 2003 to 2004 (personal communication with author).
Participants	Recruitment: written and electronic advertisements to over 13,000 employees at 3 sites. Randomisation of 288 volunteers resulted in 134 in in‐person group (48 (36%) completed intervention), 123 in computer‐based group (15 (12%) completed intervention), 31 in wait‐list‐control (WLC) group. Demographics of the 134 participants that started the interventions (13 of whom declined to provide data): Mean age: 44.4 (SD = 9.61) Male: 64.7% Caucasian: 83.3% Married: 64.2% At least a college education: 74.1%
Interventions	'Stress to Success Workshop' with content identical for individuals in computer‐based and in‐person groups. Each session contained four 10‐minute psycho‐education modules. After each module (8 total), employees were led through a two‐minute 'mini‐relaxation'. In‐person group led by instructor in groups (ranging from 1 to 28 in size, median = 4) during the lunch period over two weeks. Iterations of the workshop were held on 11 separate occasions over the course of 8 months. The computer‐based group could complete modules any time, but encouraged to complete 8 modules over a period of 2 weeks (some completed all at once, others over more than 2 weeks).
Outcomes	Stress: Subjecive Units of Distress Scale (SUDS) measured 10 times for each session (each session intended to cover 1 week): before the session, before and after each of the 4 'mini‐relaxations', and at the end of the session. SUDS after the end of Session 2 used for analysis (post‐test data, follow‐up = 0 months). In addition, authors used a 'Stress Survey' with 8 items selected from Johnson & Johnson Health Care System Insight + Health Risk Appraisal survey and 4 items selected from Occupational Stress Inventory ‐ Revised Edition (OSI‐R). This outcome could not be quantitatively analysed because SD/SEs could not be retrieved. AK contacted authors of the study, and they were unable to retrieve data.
Notes	Additional details of methodology and results were obtained from publication of a PhD thesis (Eisen 2005). AK contacted the authors of the study for additional information.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Personal communication with the authors: random numbers table used from statistics textbook
Allocation concealment (selection bias)	Low risk	Personal communication with the authors: "Participants would have had no way of knowing how they were randomised – the participants were employees at a large manufacturing plan who expressed interest in participating in this study. They were simply informed that they would be participating in a web‐based stress management programme, or that they were being assigned to a stress management group." Researcher was not blinded to assignment, but risk was assessed as low.
Incomplete outcome data (attrition bias) All outcomes	High risk	Baseline characteristics between the two comparison groups were reported as significantly different in sex and wage type: the in‐person group had more male, hourly workers; the computer‐based group more female, salaried workers; likely due to the unavailability of computers among hourly wage workers, causing pre‐intervention drop out, resulting in systematic differences between baseline characteristics of the groups. Furthermore, both groups experienced high dropout rates, with a statistically significantly higher attrition in the computer‐based group. Results were analysed 'as‐treated'. Very few participants turned up for 1‐month follow‐up (16%, 9%) and only 'Stress Survey' results were reported.
Selective reporting (reporting bias)	High risk	The available publications did not report Subjective Units of Distress Scale (SUDS) results from 1‐week or 1‐month follow‐up times, but did report SUDS from immediately after interventions, which were statistically significantly lower than pre‐intervention. The selective reporting may have favoured the results that showed significant differences post‐intervention, rather than the no‐effect results found at 1‐month follow‐up.
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	Low risk	No other sources of bias were identified.
Multiple intervention arms (reporting bias)	Low risk	While there were more than two arms of the interventions in the study, the stated objective of the study was to compare a computer‐based version of their stress management intervention to an in‐person version, thus there was a low risk of bias for this domain.
Treatment fidelity	High risk	Differences in exposure and timing: "Although [CB] participants were encouraged to complete the module over a two‐week time period, some individuals went through the entire program over a period of a single week, while others took longer than the two week time period to complete all material." (Eisen 2005, p. 15) Technological difficulties: "Twenty‐one percent of respondents described such problems to be the main reason for their decision not to continue the program. Several respondents described having difficulty logging into the course, or finding that the program would freeze up part‐way through. One respondent described his aggravation with the technological problems he was having with the Stress to Success program and his inability to connect with a live person at the computer help desk, writing that he had been "hoping to reduce my level of stress from frustrating issues like this." Thus, we assessed the risk that the intervention was not delivered as intended as high.