French translation and validation of 3 functional disability scales for neck pain.
OBJECTIVE
To translate and assess the reliability and the construct validity of 3 functional disability scales for neck pain.


METHODS
Reliability and validity study.


METHODS
Tertiary care teaching hospital and outpatient clinic.


METHODS
One hundred one patients (mean age, 49 y).


METHODS
French translations were obtained by using the "translation-backward translation" method. Adaptations were made after a pilot study.


METHODS
Impairment outcome measures (visual analog scale [VAS] pain, neck range of motion, morning stiffness, score of neck sensitivity, radiologic score of Kellgren) and patients' perceived handicap (VAS) were recorded at the baseline visit. Three functional disability scales (Neck Disability Index [NDI], Neck Pain and Disability Scale [NPDS], Northwick Park Neck Pain Questionnaire [NPQ]) were recorded twice, at baseline visit and 24 hours later. Reliability was assessed by using the intraclass correlation coefficient (ICC) and the Bland and Altman method. Construct (convergent and divergent) validity was investigated by using the Spearman rank correlation coefficient and a factor analysis was performed.


RESULTS
Test-retest was excellent for the NPDS and NDI (ICC =.91,.93, respectively) and good for the NPQ (ICC =.84). The Bland and Altman method showed no systematic trend. Expected convergent and divergent validity were observed only for the NPDS; 3 main factors were extracted by factor analysis and explained 78% of the cumulative variance.


CONCLUSIONS
The 3 translated scales are valid, but the NPDS seems to have the best construct validity.
Wlodyka-Demaille
Samantha
S
Department of Physical and Rehabilitation Medicine, Hôpital Cochin, Université René Descartes, Paris, France.
Poiraudeau
Serge
S
Catanzariti
Jean-François
JF
Rannou
François
F
Fermanian
Jacques
J
Revel
Michel
M
D000328:Adult; D000368:Aged; D001007:Anxiety; D004185:Disability Evaluation; D005260:Female; D005602:France; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000145:classification* / Q000191:economics / Q000534:rehabilitation; D010147:Pain Measurement; D010865:Pilot Projects; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014177:Translations