title: Efficacy and cost-effectiveness of a web-based and mobile stress-management intervention for employees: design of a randomized controlled trial.
abstract: BACKGROUND
  Work-related stress is associated with a variety of mental and emotional problems and can lead to substantial economic costs due to lost productivity, absenteeism or the inability to work. There is a considerable amount of evidence on the effectiveness of traditional face-to-face stress-management interventions for employees; however, they are often costly, time-consuming, and characterized by a high access threshold. Web-based interventions may overcome some of these problems yet the evidence in this field is scarce. This paper describes the protocol for a study that will examine the efficacy and cost-effectiveness of a web-based guided stress-management training which is based on problem solving and emotion regulation and aimed at reducing stress in adult employees.
  
  
  METHODS
  The study will target stressed employees aged 18 and older. A randomized controlled trial (RCT) design will be applied. Based on a power calculation of d=.35 (1-β of 80%, α = .05), 264 participants will be recruited and randomly assigned to either the intervention group or a six-month waitlist control group. Inclusion criteria include an elevated stress level (Cohen's Perceived Stress Scale-10 ≥ 22) and current employment. Exclusion criteria include risk of suicide or previously diagnosed psychosis or dissociative symptoms. The primary outcome will be perceived stress, and secondary outcomes include depression and anxiety. Data will be collected at baseline and seven weeks and six months after randomization. An extended follow up at 12 months is planned for the intervention group. Moreover, a cost-effectiveness analysis will be conducted from a societal perspective and will include both direct and indirect health care costs. Data will be analyzed on an intention-to-treat basis and per protocol.
  
  
  CONCLUSIONS
  The substantial negative consequences of work-related stress emphasize the necessity for effective stress-management trainings. If the proposed internet intervention proves to be (cost-) effective, a preventative, economical stress-management tool will be conceivable. The strengths and limitations of the present study are discussed.
  
  
  BACKGROUND
  German Register of Clinical Studies (DRKS): DRKS00004749.
authors.affiliation: Division of Online Health Training, Innovation Incubator, Leuphana University, Lueneburg, Germany. heber@inkubator.leuphana.de
authors.forename: Elena
authors.initials: E
authors.lastname: Heber
authors.forename: David Daniel
authors.initials: DD
authors.lastname: Ebert
authors.forename: Dirk
authors.initials: D
authors.lastname: Lehr
authors.forename: Stephanie
authors.initials: S
authors.lastname: Nobis
authors.forename: Matthias
authors.initials: M
authors.lastname: Berking
authors.forename: Heleen
authors.initials: H
authors.lastname: Riper
mesh_terms: D000328:Adult; D040421:Cell Phone; D003362:Cost-Benefit Analysis; D006801:Humans; D020407:Internet; D001523:Mental Disorders / Q000628:therapy*; D009786:Occupational Health Services / Q000191:economics; D012107:Research Design; D013315:Stress, Psychological / Q000628:therapy*; D016896:Treatment Outcome