Reliability and construct validity of the Spanish version of the 6-item CTS symptoms scale for outcomes assessment in carpal tunnel syndrome

Table 2 Results of the CTS-6 Reliability Analysis (N = 40)

Internal consistency. Calculated SEM and cross-sectional precision estimates for CTS-6 scores using Cronbach alpha coefficient and SD observed during field testing
Cronbach alpha coefficient	SD of CTS-6 scores	SEM	Range of cross-sectional precision of CTS-6 scores 95 % confidence level
0.81	0.68	0.3	Observed score +/−0.59
Test-retest reproducibility. Calculated longitudinal SEM of differences (SEM diff) based on test-retest reliability coefficient (ICC_2,1) and the SD of baseline scores
Mean difference score (95 % CI)^a	ICC_(2,1) (95 % CI)^a	SEMdiff	MDC (95)
0.09 (−0.07–0.26)	0.85 (0.71–0.92)	0.36	0.70

ICC _(2,1) Intraclass correlation coefficient: two-way random effect model (absolute agreement definition), MDC (95) minimal detectable change 95 % CI
^aMean difference between scores recorded in 2 successive administration times 1 week apart. CI = confidence interval

ISSN: 1471-2474