Cross-cultural adaptation of the Czech version of the core outcome measures index for low back and neck pain.

Purpose: The Core Outcome Measures Index (COMI) is a short, multidimensional instrument translated into several languages that covers five domains recommended in the assessment of outcome in patients with low-back and neck pain. The purpose of this study was to cross-culturally adapt the COMI from English to Czech language and to test the face and construct validity and reproducibility of its results in patients with low-back and neck pain.

Methods: Participants (n = 125) were included from primary and secondary care. The participants reported moderate pain and disability levels. All participants filled in the COMI forms before and after surgery. Descriptive statistics, Wilcoxon paired test, Crombach's alpha, principal component analysis and information entropy calculation were used.

Results: The instrument was successfully forward and back-translated. It can be seen that the questionnaire applied as part of our intervention study produces answers with a sufficient degree of variability and with a satisfactory degree of representation of extreme values. It can be also seen that the questionnaire can diagnose an objectively occurring change associated with the surgeon within the intervention procedure. Our other findings support the idea of ​​a possible reduction in the number of questions that measure the same latent variable. Our investigations also showed that it is possible to reduce the range of the point scale of the perception of pain to 5 degrees of intensity and thus unify the range with the other questions.

Conclusion: The Czech COMI shows acceptable properties and is thus suitable to use as a short instrument for measuring important domains in patients with low-back and neck pain.