Quality of work incapacity assessment in the Swiss disability insurance system.

Quality of medical assessment of work incapacity has been poorly investigated, despite the enormous costs engendered by transient incapacity of work and permanent disability. This study examined some indices of quality from a stratified, random sample (n = 120) of assessments performed by expert assessors of the Swiss disability insurance. The distribution of work incapacity (WI) percentages over a 100% scale showed a clustering around key values significantly associated with financial disability benefits. The precision of WI, expressed as the level of quantitative exactness, was found to be high in 74% (95% CI: 66-82%) of current WI assessments, and in 62% (95% CI: 53-71%) of maximal WI assessments. Disagreement was observed in 17% of cases when comparing two ways of expressing WI by the same physician (95% CI: 10-23%). This exploratory study is limited by the general lack of objective criteria and standards. Further theoretical and empirical developments are needed to determine standardized criteria and clear guidelines for medical assessments of WI, as well as for evaluating their quality.