Assessing mental workload in the return-to-work process: a question of perspective

Introduction
Mental workload is an important psychosocial factor influencing work disability and return-to-work management. Despite its well-documented relevance to work and human interaction, the lack of consensus about its definition and its assessment makes it difficult to take it into account appropriately. Clarification of the construct of mental workload in the work rehabilitation context is therefore needed.

Methods
A concept analysis was conducted to systematically clarify the nature of mental workload according to eight steps, including in particular the identification of the different uses, the attributes and the empirical referents. A literature review was realised including English and French papers between 2000 and 2010. Relevant keyword (e.g., mental workload, cognitive load) searches were done in dictionaries, databases, reference books and specialized websites.

Results
Mental workload is commonly used according to two perspectives: 1) a work condition and 2) a work consequence. Return to work being individually oriented, only the work consequence perspective was used to further analyze the construct. Attributes identified were a mental state: 1) related to the effort resulting from accomplishing work at a given level of performance; 2) varying on a continuum from underload to overload, with a comfortable mental workload existing between these extremes and 3) accompanied by positive or negative cognitive and affective effects depending on the level on the continuum. Actual assessment techniques do not cover all the identified attributes, the subjective measures being the closest one.

Discussion
A concept analysis is a systematic method useful to clarify an ambiguous construct and to inform tool selection. Subjective measures appear to be the most relevant to assess mental workload in the work consequence perspective. However, these concept analysis' results should guide the development of a new tool in order to offer clinicians and researchers a tool covering all the identified mental workload's attributes.