A method for Effect Modifier Assessment in ergonomic intervention studies - The EMA-Method

Ergonomic intervention research includes studies in which researchers introduce or monitor changes in the work environment in order to assess impact on risk factors and / or health. In the systematic review by Westgaard & Winkel (2011) it was concluded, among other things, that there are many changes in and around production systems that can lead to effects on musculoskeletal and mental health and / or corresponding risk factors; eg various forms of downsizing (including rumors of downsizing), management style and parallel interventions. Outcome variables for both intervention and control groups may therefore be influenced by such contextual factors that are not included in the intervention, ie effect modifiers.
On this background, we have developed a method for assessing possible effect modifications.