title: Predictors of shoulder pain and disability index (SPADI) and work status after 1 year in patients with subacromial shoulder pain.
abstract: BACKGROUND
  Shoulder pain is a common complaint in primary health care and has an unfavourable outcome in many patients. The objectives were to identify predictors for pain and disability (SPADI) and work status in patients with subacromial shoulder pain.
  
  
  METHODS
  Secondary analyses of data from a randomized clinical controlled trial were performed. Outcome measures were the absolute values of the combined Shoulder Pain and Disability Index (SPADI) and work status 1 year after treatment with supervised exercises (SE) or radial extracorporeal shockwave therapy (rESWT). Predictors of outcome were investigated using multiple linear regression (SPADI) and logistic regression (work status).
  
  
  RESULTS
  104 patients were included. Low education (≤ 12 years), previous shoulder pain, and a high baseline SPADI score predicted poor results with these variables explaining 29.9% of the variance in SPADI score at 1 year. Low education and poor self-reported health status predicted a work status of "not working": Odds Ratio, OR = 4.3(95% CI (1.3 to 14.9)), p = 0.02 for education, and OR = 1.06 (95% CI (1.0 to 1.1)), p = 0.001 for self-reported health status, respectively. Adjustments for age, gender, and treatment group were performed, but did not change the results.
  
  
  CONCLUSIONS
  Education was the most consistent predictor of pain and disability, and work status at 1 year follow-up. Also, baseline SPADI score, previous shoulder pain and self-reported health status predicted outcome.
  
  
  BACKGROUND
  Clinical trials NCT00653081.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Ullevaal, and Medical Faculty, University of Oslo, Norway. kaiabe@medisin.uio.no
authors.forename: Kaia
authors.initials: K
authors.lastname: Engebretsen
authors.forename: Margreth
authors.initials: M
authors.lastname: Grotle
authors.forename: Erik
authors.initials: E
authors.lastname: Bautz-Holter
authors.forename: Ole Marius
authors.initials: OM
authors.lastname: Ekeberg
authors.forename: Jens Ivar
authors.initials: JI
authors.lastname: Brox
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004185:Disability Evaluation; D004651:Employment / Q000639:trends; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D012720:Severity of Illness Index; D020069:Shoulder Pain / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D018582:Sick Leave / Q000639:trends*; D014938:Work Capacity Evaluation; D055815:Young Adult