The construct validity of the IWB was seen to be established through convergence between its scores and scores of numbers of chronic conditions (r=¬0.96), number of physician contacts (r= 0.55), etc., and discriminant evidence that eg. the correlation between IWB on as given day and self rated well being on days successively distant decreased systematically (from 0.46 when both relate to the same day, to 0.36 when the well being measure related to 8 days previously).