The "value" of functional independence measure scores

Functional independence measure (FIM) scores are frequently used as if the various sections are of equal importance and as if the interval between each score is equal. We tested this hypothesis by using marketing research techniques to assess the value to rehabilitation nurses and therapists of four of the six sections. Communication was valued more highly than continence, mobility and self care in that order. The interval between the scores is not equal, with difference between a FIM 2 and 3 being greater than between a FIM 5 and 6. However, when the other difficulties such as interexaminer reliability are considered, these score differences are not great. We concluded that for practical purposes FIM scores may be used as if they were of equal interval spacing, and the scores of the various sections may be added together.