Reconsidering the Roland-Morris Disability Questionnaire: time for a multidimensional framework?
METHODS
Cross-sectional design.


OBJECTIVE
To explore (1) the factor structure of the Roland-Morris Disability Questionnaire (RMDQ), (2) whether there is a dominant factor, and (3) whether the potential factors are unique predictors of other aspects related to back pain.


BACKGROUND
The RMDQ is one of the most recommended back-specific questionnaires assessing disability. The RMDQ is scored as a unidimensional scale summarizing answers to all 24 questions (Yes/No) regarding daily life functioning. However, there are indications that the scale is multidimensional.


METHODS
Patients (n = 457; age, 18-60 yr) with 8 to 12 weeks of back pain filled in questionnaires assessing subjective health complaints, emotional distress, instrumental and emotion-focused coping, and fear voidance behavior at baseline. A total of 371 patients (81.7%) filled in the RMDQ. Exploratory factor analysis was used to examine the factor structure of RMDQ items. Multiple regression analyses were used to assess whether the derived factors predicted relevant problems in back pain differently.


RESULTS
Exploratory factor analysis showed indices of model fit for a 3-factor solution after removing 2 items because of low prevalence (19 and 24). Two items were removed because of cross-loadings and low loadings (2 and 22). No support for a dominant factor was found as the 3 factors were only moderately correlated (r = 0.34-0.40), and the ratio between the first and second eigenvalue was 2.6, not supporting essential unidimensionality. "Symptoms" were the factor that most strongly predicted subjective health complaints, whereas "avoidance of activity and participation" predicted fear avoidance behavior, instrumental and emotional coping. "Limitation in daily activities" did not predict any of these variables.


CONCLUSIONS
The main findings of our study are that the RMDQ consists of 3 independent factors, and not 1 dominant factor as suggested previously. We think the time is now ripe to start treating and scoring the RMDQ as a multidimensional scale.


METHODS
N/A.
*Department of Occupational Therapy, Physiotherapy, and Radiography, Faculty of Health and Social Sciences, Bergen University College, Bergen, Norway †Department of Global Public Health and Primary Care, Physiotherapy Research Group, University of Bergen, Bergen, Norway ‡Department of Physiotherapy, Haukeland University Hospital, Bergen, Norway §Department of Physical Medicine and Rehabilitation, Innlandet Hospital Trust, Ottestad, Norway; and ¶Regional Centre for Child and Adolescent Mental Health and Welfare, Uni Research Health, Bergen, Norway.
Liv Heide
LH
Magnussen
Hildegunn
H
Lygren
Liv Inger
LI
Strand
Eli Molde
EM
Hagen
Kyrre
K
Breivik
D000223:Adaptation, Psychological; D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000175:diagnosis* / Q000523:psychology; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005239:Fear / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011795:Surveys and Questionnaires; D055815:Young Adult