Cross-cultural adaptation and validation of the Norwegian version of the Core Outcome Measures Index for low back pain.
OBJECTIVE
The Core Outcome Measures Index (COMI) is a short multidimensional scale covering all domains recommended to be included as outcome measures for patients with low back pain (LBP). The purpose of the present study was to translate and cross-culturally adapt the COMI into Norwegian and to test clinimetric properties of the Norwegian COMI version in patients with non-specific LBP recruited from various clinical settings.


METHODS
Ninety patients with non-specific LBP from primary care and hospital settings participated in the validation part and 61 also in the reproducibility part of the study (1 week apart). Acceptability, data quality, reproducibility and construct validity were investigated.


RESULTS
The questionnaire was well accepted and with little missing data and end effects. Reliability in terms of intraclass correlations (ICC) was satisfactory for the COMI index [0.89 (95 % CI 0.82-0.94)] and most single-core items. Agreement was acceptable for the COMI index [standard error of measurement (SEM(agreement)) 0.80, minimal detectable change (MDC(individual)) 2.21], but exceeded the minimal standard of acceptability in some of the individual core items. Construct validity was acceptable for the COMI index.


CONCLUSIONS
The Norwegian version of the COMI index shows acceptable clinimetric properties in our patient population, but some of the sub-items had shortcomings. Our study, however, support the usefulness of the COMI index as an applicable stand-alone global scale when a light respondent burden is advisable.
Communication and Research Unit for Musculoskeletal Disorders (FORMI), Oslo University Hospital and University of Oslo, Building 37B, Nydalen, Box 4956, 0424 Oslo, Norway. Kjersti.Storheim@oslo-universitetssykehus.no
Kjersti
K
Storheim
Jens Ivar
JI
Brox
Ida
I
Løchting
Erik L
EL
Werner
Margreth
M
Grotle
D003431:Cross-Cultural Comparison; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009664:Norway; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011594:Psychometrics / Q000379:methods; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires