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.