Development and Construct Validity of the Work Instability Scale for People With Common Mental Disorders in a Sample of Depressed and Anxious Workers: A Rasch Analysis

Abstract

Background: Sick leave due to common mental disorders, encompassing depression and anxiety disorders, is high. Capturing early signs of reduced function could aid adjustments of work tasks and environment and, thus, endorse a pro-active approach to occupational and health care interventions to prevent long-term sick-leave spells. However, few measurements exist to identify early signs of imbalance, and none that is illness-specific. The aim of this study was to develop a work instability scale for people with common mental disorders and to test the fundamental psychometric properties of the scale. Methods: Participants were working adults 18-65 years old with depression or anxiety. The scale development started with qualitative interviews (n = 27) which informed the drafting of a dichotomous, self-report questionnaire. Cognitive debriefing (n = 12) was used to check face validity and modify the draft. Internal construct validity of the draft was tested using Rasch analysis (n = 128). The work ability index was used as a comparator measure. Results: The initial 63-item draft showed poor fit to Rasch model expectations. Items displaying poor fit or local response dependency were stepwise removed, resulting in a unidimensional 34-item scale fitting the model expectations, and with no differential item functioning. Person-item threshold distribution showed that the scale is better suited to measure low to moderate work instability, than to measure high instability. Correlations between the newly developed scale and the work ability index showed a significant, moderately strong correlation. Conclusions: In the initial target sample, the 34-item scale showed acceptable fundamental properties and internal construct validity. Further validation of the scale in a larger sample, including tests for external validity, is warranted.

Rasch Model-Based Adversity Quotient: A Potential Instrument for Assessing Madrasah Students’ Literacy

“…While the Rasch model can see the interaction of respondents and items at the same time. Therefore, validity needs to be developed using the Rasch model [43]. For example, the Rasch model developed by Andrich is used for political data based on two basic theorems, namely the level of ability/agreement of individuals and the level of difficulty of items to be approved [17].…”

Supporting workers with mental health problems at work: challenges and avenues

“…To assess and monitor the abilities to accomplish the work role, it is vital to consider at-work outcomes, such as health-related work functioning, work limitations, work instability, and work capabilities (21)(22)(23)(24). Ideally, such outcomes -existing or to be developed -are at the intersection of a persons' health and work performance, reflect the ability and/or need of a person to meet the work demands given the available personal and/or environmental resources, and provide information for the content and timing of work accommodations.…”

Validity of the Capacity to Work Index: Development of an Instrument to Measure Work Capacity in Relation to Depression and Anxiety in the General Working Population

“…No specific instrument to assess capacity to work in relation to CMDs in a general working population is available. Most instruments have been developed for clinical use for individuals with CMD seeking care [8][9][10][11].…”

“…The Lam Employment Absence and Productivity Scale (LEAPS) was developed as a tool for clinical use to assess and monitor work functioning in the specific group of patients with major depressive disorders [10]. The Work Instability Scale for People with Common Mental Disorders (WIS-CMD) was developed to measure work instability described as early signs of reduced function for use at occupational health services, work places or primary care [9]. The existing instruments, WAI, WRFQ, mini-ICF-APP, LEAPS, and WIS-CMD, measure to different degrees generic assessments of work capacity in the general population and/or in clinical populations.…”