Grimby & Nilsson comment on various methods used to improve the reliability of qualifiers in both the International Classification of Functioning, Disability and Health (ICF) and the Functional Independence Measure (FIMTM). We are aware of these methods and the problems of both reliability and linearity of functional outcome measures. As we indicated in our paper, our intention was not to develop, or for that matter replicate, a functional assessment measure, but to determine if individual ICF categories and their qualifiers could be used as components of an assessment tool or an outcome measure. Our motivation was to promote broader acceptance of the ICF, particularly in the rehabilitation community, and to encourage its use in countries and settings where the use of proprietary instruments is not affordable. We note that the authors of this letter agree with our approach; namely that we should test the reliability of the ICF categories against the items of a well-known and well-accepted instrument, whose psychometric properties have been well described in the literature.

We note that, throughout their letter, Grimby & Nilsson refer to the FIM manual to outline a detailed description and exact definition of the items. It is exactly this detailed description that makes the FIM difficult to work with, as only those who have considerable experience and understanding of the definitions and who either recall or have ready access to the contents of the FIM manual will be able to achieve good inter-rater reliability. The emphasis on extensive training, credentialing and re-credentialing is a cost burden that could be avoided. This means examining and developing options of measurement of function that may be less cumbersome and costly than the FIM. Our paper describes how, with relatively minor modifications, limited experience, and brief instructions, adequate inter-rater reliability can be achieved with ICF categories, a reliability that matches or excels that of the reliability of individual items of the FIM.

We agree with Grimby & Nilsson that not all ICF items have sufficiently detailed qualifier definitions. However, we consider that, in view of the early stage of the work of using the ICF and exploring the viability of using the ICF as an outcome measure, our work represents a significant advance.

To address the major concern expressed in the letter, we repeat that we did not intend to replicate the FIM or establish an outcome measure based on the ICF, which replicates the FIM. We used this approach to advance the understanding of the qualifiers and the psychometric properties of the qualifiers of the ICF.

Specifically, we would like to point out to Grimby & Nilsson that any third-level item of the ICF is automatically included in the second-level item. While the third-level items will have more detailed specifics in their description, this description is also included in the second-level item by definition of the ICF classification. Therefore, the concerns about Bathing requiring item d5101 instead of only using d510 are misplaced, as this is already accommodated within the ICF terminology and classification. We have chosen in our cross-matching generally to use the second-level ICF categories, except for d4551, which is the specific item of Climbing stairs, and matches the requisite FIM item.

When one takes the hierarchical structure of the ICF into account, the cross-match as suggested by Grimby & Nilsson is in broad agreement with the cross-match that we have used. While we would consider that Grooming can be d520, the items not covered by d520 are automatically covered by Bathing d510. This would not make the items totally comparable but nonetheless, the breadth of information that is gathered for the FIM is also included in the ICF items. These comments are similarly relevant to the concerns raised about Toileting and Bladder and Bowel management. As d530 is a stand-alone item in Toileting, the parts of d5300 and d5301 are already accommodated within that description and therefore the information is already adequately gathered. Collecting d5300 and d5301 would introduce redundancy.

We draw attention to the paragraph in the methods section addressing the broader aspects of communications in our paper. It deals with aspects of receiving non-verbal communication and producing non-verbal communication, and we refer them to that paragraph in the original paper.

We note that Grimby & Nilsson agree with d720 as being the most appropriate item to link social interaction. The definition of memory according to the FIM is one definition that can be used, but is not a gold-standard definition of memory. Although we agree that there is no direct comparison to the FIM definition of memory in the ICF, we consider that b144 is a reasonable approximation.

We thank Grimby & Nilsson for their comments and for contributing to the discussion of the feasibility of using ICF categories as components of ADL measures. We look forward to other comments and discussions from the broader rehabilitation community.

Friedbert Kohler, MBBS, FAFRM1,2, Carol Connolly, MBChB, FAFRM1, Aroha Sakaria, Nurse, BAN1, Kimberly Stendara, PT1, Mark Buhagiar, B(ap)CPT1 and Mohammad Mojaddidi, MBBS1

From the 1Department of Rehabilitation Medicine, Braeside Hospital, HammondCare and 2School of Public Medicine and Community Health, University of NSW, Sydney, Australia. E-mail: F.Kohler@unsw.edu.au