Development of the construction employee's workplace mental health questionnaire: The two continua model approach

Purpose – Based on the two continua model, this study aims to develop and validate the Construction Employee's Workplace Mental Health Questionnaire (CEWMHQ) in the Vietnamese construction context. Unlike conventional approaches that solely assess mental illness or psychological wellbeing, the CEWMHQ simultaneously measures both dimensions to capture a more comprehensive picture of construction employees' mental health. Design/methodology/approach – First, an initial pool of items was established through a review of previous studies and practitioner interviews. A list of 13 measurement items was then developed using the Delphi method and the pilot test. Data were collected from 422 Vietnamese construction employees through a snowball sampling method. The CEWMHQ was then validated through reliability, construct, convergent and discriminant tests. After that, K-means clustering was applied to identify cut-off values for the wellbeing and mental illness axes. Findings – The CEWMHQ was validated with 13 items, including seven for wellbeing and six for mental illness. Using K-means clustering (K = 2), cut-off values were set at 3.496 for wellbeing and 2.394 for mental illness. Employees were classified into four groups: flourishing (40.0%), struggling (17.1%), languishing (23.5%) and floundering (19.4%). Originality/value – To the best of the authors' knowledge, this study is among the first to design a mental health measurement tool tailored for construction employees, reflecting both illness and positive wellbeing. The CEWMHQ contributes a validated instrument that supports researchers, practitioners and policymakers in monitoring mental health among the construction workforce.