title: Pain, disability, and satisfaction outcomes and predictors of outcomes: a practice-based study of chronic low back pain patients attending primary care and chiropractic physicians.
abstract: BACKGROUND
  Few studies exist on the prognostic value of demographic, clinical, or psychosocial factors on long-term outcomes for patients with chronic low back pain.
  
  
  OBJECTIVE
  This study reports on long-term pain and disability outcomes for patients with chronic low back pain, evaluates predictors of long-term outcomes, and assesses the influence of doctor type on clinical outcome.
  
  
  METHODS
  Sixty chiropractic (DC) and 111 general practice (MD) physicians participated in data collection for a prospective, longitudinal, practice-based, observational study of ambulatory low back pain of mechanical origin. The primary outcomes, measured at 6 months and 12 months, were pain (by using the Visual Analog Scale), and functional disability (by using the Revised Oswestry Disability Questionnaire). Satisfaction was a secondary outcome.
  
  
  RESULTS
  Overall, long-term pain and disability outcomes were generally equivalent for patients seeking care from medical or chiropractic physicians. Medical and chiropractic care were comparable for patients without leg pain and for patients with leg pain above the knee. However, an advantage was noted for chronic chiropractic patients with radiating pain below the knee after adjusting for baseline differences in patient and complaint characteristics between MD and DC cohorts (adjusted differences = 8.0 to 15.2; P <.002). A greater proportion of chiropractic patients were satisfied with all aspects of their care (P =.0000). The strongest predictors of primary outcomes included an interaction of radiating pain below the knee with provider type and baseline values of the outcomes. Income, smoking, comorbidity, and chronic depression were also identified as predictors of outcomes in this study.
  
  
  CONCLUSIONS
  Chiropractic care compared favorably to medical care with respect to long-term pain and disability outcomes. Further study is required to explore the advantage seen for chiropractic care in patients with leg pain below the knee and in the area of patient satisfaction. Identification of patient and treatment characteristics associated with better or worse outcomes may foster changes in physicians' practice activities that better serve these patients' needs.
authors.affiliation: Western States Chiropractic College, Division of Research, Center for Outcome Studies, Portland, OR 97230, USA.
authors.forename: J
authors.initials: J
authors.lastname: Nyiendo
authors.forename: M
authors.initials: M
authors.lastname: Haas
authors.forename: B
authors.initials: B
authors.lastname: Goldberg
authors.forename: G
authors.initials: G
authors.lastname: Sexton
mesh_terms: D000328:Adult; D002684:Chiropractic; D002908:Chronic Disease; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D007866:Leg; D017116:Low Back Pain / Q000145:classification / Q000175:diagnosis* / Q000523:psychology / Q000628:therapy*; D008297:Male; D009922:Oregon; D010147:Pain Measurement; D017060:Patient Satisfaction; D010818:Practice Patterns, Physicians'; D011320:Primary Health Care; D011446:Prospective Studies; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014481:United States