A comparative performance analysis of the International Classification of Functioning, Disability and Health and the Item-Perspective Classification framework for classifying the content of patient reported outcome measures.

Inter-rater agreement on classification data was excellent. The IPC framework provided a unique classification of the respondent's judgment during item response and classified more items using fewer categories, indicated greater content overlap across items and was able to describe the relationship between multiple concepts presented within the context of a single item. The ICF provided a unique classification of item content relating to aspects of disability and generated more detailed and precise descriptions. A combined approach provided a rich description (detailed codes) with each framework providing complementary information. The benefits of this approach in instrument development and content validation require further investigation.