Developing a shortened spine functional index (SFI-10) for patients with sub-acute/chronic spinal disorders: a cross-sectional study

Table 2 Criterion validity comparing SFI-10 versions with the SFI-25 and FRI

		SFI-25	SFI-10
Phase		SFI-25	Version A Qualitative ‘Concept’	Version B Quantitative ‘Factorial’	Version C Quantitative ‘Rasch’	Version D Computerized ‘Random’
Australian sample (PCC)	SFI-25 ( n = 505)		^# 0.967*	0.951*	0.939	0.955*
Australian sample (PCC)	FRI ( n = 343)	0.818	^# 0.810**	0.788**	0.792**	0.788**
Pooled International sample (SCC) [19, 22, 23, 26]	SFI-25 ( n = 1433)		^# 0.950*	0.934	0.912	0.938

SFI indicates Spine Functional Index, PCC Pearson’s Correlation Coefficient for normally distributed data, FRI Functional Rating Index
*PCC/SCC: r > 0.95 with the SFI-25; and **r > 0.70 with the FRI as the indicator of potential suitability to substitute for the SFI-25
^# PCC/SCC Highest value was the preferred version

ISSN: 1471-2474