Differences and limitations of the BASFI and DFI based on literature review by Ruof and Stucki13
| BASFI | DFI | Limitations |
|---|---|---|
| BASFI, Bath Ankylosing Spondylitis Functional Index; DFI, Dougados Functional Index; VAS, visual analogue scale. | ||
| 10 Items | 20 Items | DFI requires more time to complete |
| Score based on 10 cm VAS | Score based on 3 point scale | DFI 3 point scale limits expression of change compared with BASFI (sensitivity has been enhanced for DFI with a modified 5 point scale) |
| 7 Items similar to DFI, 3 additional items improve content validity and the spectrum of item difficulty | 7 Items similar to BASFI, some items are redundant and some deal with symptoms rather than function | Construct and content validity of DFI inferior to those of the BASFI |
| Can discriminate the effects of a 3 week intensive physical therapy treatment period | Cannot discriminate the effects of a 3 week intensive physical therapy treatment period | Distribution of DFI scores shows tendency toward normal scores, which may inhibit further capture of improvement in patients with mild disability in physical therapy trials |
| BASFI and DFI do not provide rules for handling missing data | ||