Self-reported severity measures as predictors of return-to-work outcomes in occupational back pain.
BACKGROUND
We test an array of biopsychosocial, cognitive-behavioral, and work-related factors to identify the best predictors of work disability following a back injury.


METHODS
We test the validity of alternative severity measures in predicting the likelihood of four distinct, mutually exclusive patterns of post-injury employment in the first year after onset of back pain. The study sample includes 959 participants in the ASU Healthy Back Study, a prospective cohort study of workers who filed claims for occupational back pain between 1999 and 2002. Self-reported severity measures include: NRS-101 measures of the intensity of back or leg pain, Roland-Morris scale of functional disability, and mental and physical components of the SF-12.


RESULTS
All the severity measures have significant predictive power on return-to-work outcomes even after 1 year. Baseline physical functioning and overall mental and physical health status are more predictive of specific patterns of post-injury employment than pain intensity measures, possibly because there is considerable idiosyncratic variation in the pain intensity measures. The mental component of the SF-12, in particular, is relatively robust to alternate specifications, consistently statistically significant, and has the lowest probability significance level in explaining patterns of employment 1 year after injury.
Baldwin
Marjorie L
ML
School of Health Management and Policy, W P Carey School of Business, Arizona State University, Tempe, AZ 85287-4506, USA. Marjorie.Baldwin@asu.edu
Butler
Richard J
RJ
Johnson
William G
WG
Côté
Pierre
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D017116:Low Back Pain / Q000523:psychology / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000523:psychology / Q000534:rehabilitation*; D016272:Occupational Health; D010146:Pain / Q000534:rehabilitation; D011446:Prospective Studies; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D016896:Treatment Outcome; D014938:Work Capacity Evaluation