Citation: Shiri, R.; Turunen, J.; Kausto, J.; Leino-Arjas, P.; Varje, P.; Väänänen, A.; Ervasti, J. The Effect of Employee-Oriented Flexible Work on Mental Health: A Systematic Review. Healthcare 2022, 10, 883. https:// doi.org/10.3390/healthcare10050883 Academic Editor: Pedram Sendi Received: 7 April 2022 Accepted: 6 May 2022 Published: 10 May 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). healthcare Review The Effect of Employee-Oriented Flexible Work on Mental Health: A Systematic Review Rahman Shiri * , Jarno Turunen , Johanna Kausto, Päivi Leino-Arjas, Pekka Varje, Ari Väänänen and Jenni Ervasti Finnish Institute of Occupational Health, P.O. Box 18, Työterveyslaitos, FI-00032 Helsinki, Finland; jarno.turunen@ttl.fi (J.T.); johanna.kausto@ttl.fi (J.K.); paivi.leino-arjas@ttl.fi (P.L.-A.); pekka.varje@ttl.fi (P.V.); ari.vaananen@ttl.fi (A.V.); jenni.ervasti@ttl.fi (J.E.) * Correspondence: rahman.shiri@ttl.fi Abstract: The effect of flexible work on mental health is not well known. The aim of this systematic review was to assess the effects of employee-oriented flexible work on mental health problems and associated disability. Literature searches were conducted in the PubMed, Scopus, Web of Sciences, Cochrane Library, PsycINFO, ProQuest and EconPapers databases from their inception through October-November 2020. Sixteen studies on the associations of worktime control, working from home, or flexible working arrangements with mental health related outcomes were included in the review: one cluster randomized controlled trial, two non-randomized controlled trials, two cross-over studies, and 11 prospective cohort studies. Three reviewers independently assessed the met-hodological quality of the included studies and extracted the data. The included studies differed in design, intervention/exposure, and outcome, so meta-analysis was not carried out and qualitative results were reported. A few prospective cohort studies found that low employees’ control over worktime increases the risk of depressive symptoms, psychological distress, burnout, and accumulated fatigue. One cross-over and a few cohort studies found small beneficial effects of working partly from home on depressive symptoms, stress, and emotional exhaustion. A small number of controlled trials, cross-over or cohort studies found that flexible working arrangements increase employees’ control over working hours, but have only modest beneficial effects on psychological distress, burnout, and emotional exhaustion. This systematic review suggests that employee-oriented flexible work may have small beneficial effects on mental health. However, randomized controlled trials and quasi-experimental studies are needed to identify the health effects of flexible work. Keywords: anxiety; depression; mental disorders; telecommuting; schedule control; worktime control; work schedule 1. Introduction Globally, the COVID-19 pandemic markedly increased working from home, at least temporarily [1]. Working from home as an example of telework is part of flexible working arrangements. Some previous studies have reported that flexible working arrangements are linked to better balance of work and private life, and consequently lead to longer work careers [2,3]. However, other studies have reported that flexible working arrangements may increase work–private life conflict [4], and have no beneficial effects on health [5]. Depending on the organization, flexibility may entail flexibility in time, in space, or in the way the work is performed [6]. Flexible work comprises company-oriented and employee-oriented flexibility. Company-oriented flexibility involves employers extending, modifying, or reducing working hours or other work arrangements according to orga- nizational objectives, for example, to better meet a financial budget. Employee-oriented flexible work permits workers to modify when, where, or how to work. It can refer to autonomy regarding working times (i.e., worktime control) or working location or other Healthcare 2022, 10, 883. https://doi.org/10.3390/healthcare10050883 https://www.mdpi.com/journal/healthcare