The Mediating Role of General and Cognitive Stress on the Effect of an App-Based Intervention on Productivity Measures in Workers: Randomized Controlled Trial
Authors: de Miquel Carlota , Moneta Maria Victoria , Weber Silvana , Lorenz Christopher , Olaya Beatriz , Haro Josep Maria 
Published: March 2023

Background
Loss of productivity is a result of absence from work (absenteeism) or of working with limitations due to illness (presenteeism). Recently, occupational mental health interventions have increasingly been delivered in digital format, as this is thought to be more convenient, flexible, easily accessible, and anonymous. However, the effectiveness of electronic mental health (e-mental health) interventions in the workplace to improve presenteeism and absenteeism remains unknown, and could be potentially mediated by psychological variables such as stress levels.

Objective
The aim of this study was to determine the effectiveness of an e-mental health intervention to reduce absenteeism and presenteeism in employees, as well as to investigate the mediating role of stress in this effect.

Methods
Employees of six companies in two countries participated in a randomized controlled trial (n=210 in the intervention group and n=322 in the waitlist control group). Participants in the intervention group could use the Kelaa Mental Resilience app for 4 weeks. All participants were asked to complete assessments at baseline, during the intervention, postintervention, and at a 2-week follow-up. Absenteeism and presenteeism were assessed by means of the Work Productivity and Activity Impairment Questionnaire: General Health, while general and cognitive stress were assessed through the Copenhagen Psychosocial Questionnaire-Revised Version. Regression and mediation analyses were performed to evaluate the effect of the Kelaa Mental Resilience app on presenteeism and absenteeism.

Results
The intervention did not have a direct effect on presenteeism or absenteeism, neither at postintervention nor at follow-up. Nevertheless, general stress significantly mediated the intervention effect on presenteeism (P=.005) but not on absenteeism (P=.92), and cognitive stress mediated the effect of the intervention on both presenteeism (P<.001) and absenteeism (P=.02) right after the intervention. At the 2-week follow-up, the mediating effect of cognitive stress on presenteeism was significant (P=.04), although this was not the case for its mediating effect on absenteeism (P=.36). Additionally, at the 2-week follow-up, general stress did not mediate the intervention effect on presenteeism (P=.25) or on absenteeism (P=.72).

Conclusions
While no direct effect of the e-mental health intervention on productivity was found in this study, our findings suggest that stress reduction could mediate the effect of the intervention on presenteeism and absenteeism. As such, e-mental health interventions that address stress in employees might also indirectly reduce presenteeism and absenteeism in these employees. However, due to study limitations such as an overrepresentation of female participants in the sample and a high proportion of attrition, these results should be interpreted with caution. Future research is needed to better understand the mechanisms of interventions on productivity in the workplace.

Trial Registration
ClinicalTrials.gov NCT05924542; https://clinicaltrials.gov/study/NCT05924542