Validation of the Polish language version of the SF-36 Health Survey in patients suffering from lumbar spinal stenosis

Introduction and objective. Patient-reported outcome (PRO) questionnaires have become the standard measure for treatment effectiveness after spinal surgery. One of the most widely used generic PROs is the SF-36 Health Survey. The aim of this study was to specifically focus on validating the SF-36 Health Survey to confirm that the tool is an acceptable and psychometrically robust measure to collect HRQoL data in Polish patients with spinal stenosis. Materials and Methods. Patients were eligible if they were above 18 years of age and had been qualified for spine surgery of the lumbar region due to either discopathy or non-traumatic spinal stenosis. All patients filled-in the Polish version of the SF-36 and a demographic questionnaire. Standard validity and reliability analyses were performed. Results. 192 patients (83 women - 43.2%) agreed to take part in the study (mean age: 57.5 +/- 11.4 years). In 47 patients (24.5%), using MRI, ossification of the ligarnenta flava were found. Cronbach's alpha coefficients showed positive internal consistency (0.70-0.92). Interclass correlations for the SF-36 ranged from 0.72 - 0.86 and proved appropriate test-retest reliability. Satisfactory convergent and discriminant validity in multi-trait scaling analyses was seen. Conclusions. The Polish version of the SF-36 is a reliable and valid tool for measuring HRQoL in patients with spinal stenosis. It can be recommended for use in clinical and epidemiological settings in the Polish population. However, caution is warranted when interpreting the results of the 'role limitations due to physical health problems' and the 'role limitations due to emotional problems' scales because of floor and ceiling effects.