Patterns of Responding on the Work Ability Index Following a Compensable Injury

This study provided an updated analysis of the _Work Ability Index_ in a sample of 208 individuals undergoing vocational assessment following a compensable personal injury. Participants reported a median of three medical conditions, and the majority (147 out of 208) had between 100 and 354 days off work in the past year. Self-rated physical capacity was typically “rather poor,” while mental capacity was rated as “moderate.” These domains were significantly related. Strong associations were also found between current work ability and estimated work impairment (γ =.869), and between estimated future work ability and both current work ability (γ =.732) and estimated impairment (γ =.841). The analysis, which treated each WAI item as ordinal, revealed coherent internal relationships across items, supporting the relevance of the individual components. These findings underscore the complexity of work ability following injury and challenge the psychometric justification for summing item scores into a total index.