4.2 Cronbach’s alpha coefficients of the SSQOL and the SF-36
One of the criteria showing that a measurement is made appropriately is
its high reliability coefficient28. In our study,
Cronbach’s alpha values ranged between 0.59-0.95 in SF-36 and 0.74-0.97
in SSQOL. These values are consistent with the literature and indicate
a high level of internal consistency12, 22.
In a study comparing the World Health Organization Quality of Life BREF
(WHOQOL-BREF) scales of SSQOL, Cronbach’s alpha values of SSQOL were
found to range between 0.61-0.82 which were consistent with our study
findings31.
However, in our study, Cronbach’s alpha values of SSQOL were
relatively higher than SF-36. In one study, it was reported that SF-36
was not suitable for the assessment of stroke patients and should be
used for comparison between large groups. Reliability was found to be
low especially when the items were responded by the patient’s
relative(s)32. However, it has been reported that
SSQOL is moderately susceptible to changes in the first three months
after stroke, but further research is needed regarding this
issue21. The fact that the internal consistency of the
two scales was similar in the four similar dimensions shows that both
scales evaluated the similar structural characteristics.