Cross-cultural adaptation and validation of the Polish version of the core outcome measures index for low back pain

PURPOSE: The Core Outcome Measures Index (COMI) is a short, multidimensional outcome scale validated for the use by patients with spinal disorders. It is a recommended instrument in the Spine Society of Europe Spine Tango Registry. The purpose of this study was to produce a cross-culturally adapted and validated Polish COMI. METHODS: The cross-cultural adaptation was carried out using the established guidelines. One-hundred and sixty-nine patients with chronic low back pain were enrolled, 89 took part in the reproducibility part of the study. Data quality, construct validity and reproducibility were assessed. RESULTS: The quality of data was very good with very few missing answers and modest floor effect. Reliability expressed as intraclass correlation coefficient (ICC) was 0.90 (95 % CI 0.85–0.93) for the overall COMI score and for most of the individual core items. The minimum detectable change (MDC(95%)) was 1.79. CONCLUSIONS: The Polish version of COMI showed a favorable reproducibility similar to that of previously tested language versions. The COMI scores correlated sufficiently with existing measures. This version of the COMI is a valuable instrument for the use by Polish-speaking patients with spinal disorders. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00586-012-2607-2) contains supplementary material, which is available to authorized users