Factor structure of the pain disability index in workers compensation claimants with low back injuries.
OBJECTIVE
To examine the factor structure of a telephone-administered Pain Disability Index (PDI) and the effects of race and sex on the PDI.


METHODS
Computer-assisted telephone interviews of a cohort with occupational low back injuries.


METHODS
General community.


METHODS
Missouri workers compensation claimants (N=1329) with low back injuries.


METHODS
Not applicable.


METHODS
PDI, levels of pain severity, Social Security Disability Insurance status, and the Fear-Avoidance Behavior Questionnaire.


RESULTS
Results for the total sample and by race/sex group indicated support for a 2-factor model of the PDI corresponding to voluntary activities (eg, social, occupational, recreational) and obligatory activities (eg, activities of daily living, eating, sleeping). Additional psychometric analyses of the voluntary and obligatory subscales indicated adequate reliability and construct validity overall and in each of the race/sex groups. African Americans reported more pain-related disability on both subscales than whites. Women reported more disability on the voluntary subscale than men.


CONCLUSIONS
The results support use of the PDI as a bidimensional measure of pain-related disability, with strong psychometric properties. They also support its administration by telephone.
Tait
Raymond C
RC
Department of Psychiatry, Saint Louis University School of Medicine, 1221 S. Grand Boulevard, St. Louis, MO 63104, USA. taitrc@slu.edu
Chibnall
John T
JT
D000293:Adolescent; D000328:Adult; D019567:Back Injuries / Q000503:physiopathology*; D044383:Black People; D015331:Cohort Studies; D004185:Disability Evaluation; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D017116:Low Back Pain / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008923:Missouri; D010147:Pain Measurement; D011594:Psychometrics; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires; D044465:White People; D014942:Workers' Compensation; D001741:Black or African American