The Assessment of Residual Capacity for Work: Easier Said Than Done

Grant Duncan

This article examines the technical and practical issues surrounding the formalised procedures used to make an “objective” work-capacity assessment of people receiving wage-replacement benefits.

The primary model used in New Zealand is that implemented by ACC in 1997. This involves making a clinical assessment, with regard to medical impairment, of the occupations in which an injured person may be safely employed. A fundamental problem for this method is that overall fitness for work and disability are multi-dimensional issues, which require looking beyond the “defects” to consider the whole person as embedded in a social context of work and employment. The low reliability of impairment-based assessments is highlighted.  Alternative methods, such as functional-capacity assessments, are considered but these also have limited validity when there is no specific job situation with which to match the individual. The inclusion of “subjective” symptoms such as pain or anxiety further undermines the ability to make “objective” evaluations.

The conclusion drawn is that any tool that attempts to make a “blind” assessment of overall work capacity will be of compromised validity.