Evaluation of the Finnish Versions of the Functional Indices BASFI and DFI in Spondylarthropathy

Abstract

The aim of the study was to compare and evaluate the usefulness of Finnish versions of two functional indices used in spondylarthropathies. Seventy consecutive inpatients with different kinds of spondylarthropathies filled in self-administered questionnaires: the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Dougados Functional Index for spondylarthropathies (DFI). Cronbach's alpha as a coefficient of internal consistency was analysed for BASFI and DFI. Test-retest reliability was evaluated in 30 patients. For validity the functional indices were compared with the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), spinal movement measures of chest expansion (CE), Schober S1 test and occiput-to-wall distance (OWD), and radiological changes in the lumbar spine (RTGLS) and sacroiliac joints (RTGSI). The reproducibility of the indices BASFI and DFI was good; the intraclass correlation coefficient (ICC) for reliability was 0.99 and 0.98, and the coefficient of internal consistency (Cronbach's alpha) was 0.94 for both BASFI and DFI. The functional indices correlated well with each other, r = 0.85 (95% CI 0.78-0.90). Validity in terms of correlation coefficients between disease activity index BASDAI and functional indices BASFI and DFI was 0.74 (95% CI 0.60-0.84) and 0.69 (95% CI 0.53-0.80), respectively. BASFI and DFI correlated with spinal mobility measurements and RTGLS, but DFI did not correlate with RTGSI. Neither BASFI nor DFI correlated with ESR and disease duration, and only DFI correlated with age. In conclusion, BASFI and DFI are reliable and valid for Finnish inpatients with spondylarthropathies. It is important to know that cultural differences do not reduce the usefulness of these indices.

Adaptação cultural cruzada e validação da versão do Índice Funcional de Espondilite Anquilosante de Bath (BASFI) para o português do Brasil

“…11 These results are also in line with another study that applied the BASFI (self-administered approach in D1 and D2) and their results showed also an excellent reliability (ICC = 0.99). 15 In addition, the test-retest reliability of BASFI was good, with a high intraclass correlation coeffi cient between the two time points (24 hours interval, ICC = 0.93). 13 In opposite direction, a Mexican-Spanish version found worse results than the studies described above.…”

“…In the Finnish study only DFI showed correlation with age. 13,15 However, the BASFI Chinese version showed weak correlations both with age and disease duration. 22 In fact, it is possible that not only age but other variables combined result in disease severity and functional disability so that, as a consequence, a patient could be older but with less severe disease, while a younger patient could have more severe disease.…”

“…11,13,15 Therefore, the Brazilian-Portuguese version of BASFI can be applied in AS patients. Further studies are necessary to corroborate its measurement properties.…”

“…The validity and reliability of the original BASFI English version, as well as other language's versions, has been demonstrated. [11][12][13][14][15] In addition, the BASFI questionnaire has been approved by OMERACT IV fi lter for use as functional index in spondyloarthritis. 16 …”

Functional changes in patients with spondylarthropathy. A controlled trial of the effects of short-term rehabilitation and 3-year follow-up

“…Each item is answered on a 10-cm horizontal visual analogue scale (VAS) [2,3,5,6,9,11]. Total scores range from 0 to 10, with higher scores indicating more severe impairment.…”