German validation of the quality of life profile for spinal disorders (QLPSD).

BACKGROUND

The Quality of Life Profile for Spine Deformities (QLPSD) is a self-reporting questionnaire designed for studying patients with spinal deformities.

PURPOSE

The aim of the present study was to systematically translate the QLPSD into German (G-QLPSD) and to test its reliability and validity. Special emphasis was intended to be given to patients with different Cobb angles and ages.

METHODS

The QLPSD was systematically translated into German and was responded to in a web-based online survey by patients with idiopathic scoliosis and by healthy control individuals to carry out a matched-pair analysis. Participants aged 14 years and older were included. All participants answered a battery of validated questionnaires (SRS 22-r, PHQ-9, PANAS, FKS, WHO-5, BFI-S, PTQ). Reliability testing included Cronbach's alpha and test-retest reliability (retest 8 weeks after initial testing). Factorial, convergent, divergent, concurrent, and discriminant validity were calculated.

RESULTS

A total of 255 scoliosis patients (age 30.0 ± 16.7 years, Cobb angle 43.5° ± 20.9°) and 189 matched healthy control individuals were finally included. Cronbach's alpha for the G-QLPSD total score was 0.93 and the test-retest reliability was 0.84. The G-QLPSD total score correlated with the SRS 22-r total score (r = -0.86). All concurrently applied scores showed strong correlations with the G-QLPSD (e.g., depression score PHQ-9: r = 0.70). The matched-pair analysis of 189 pairs showed strong discriminant validity (Cohen's d = 0.78). Patients with more severe Cobb angles (≥40°) and those ≥18 years of age had significantly poorer results than patients with minor curves and younger patients.

CONCLUSION

The G-QLPSD proved to be a highly reliable and valid instrument that can be recommended for clinical use in scoliosis patients.