title: Dose-response for chiropractic care of chronic low back pain.
abstract: BACKGROUND
  There have been no trials of optimal chiropractic care in terms of number of office visits for spinal manipulation and other therapeutic modalities.
  
  
  OBJECTIVE
  To conduct a pilot study to make preliminary identification of the effects of number of chiropractic treatment visits for manipulation with and without physical modalities (PM) on chronic low back pain and disability.
  
  
  METHODS
  Randomized controlled trial with a balanced 4x2 factorial design. Conducted in the faculty practice of a chiropractic college outpatient clinic.
  
  
  METHODS
  Seventy-two patients with chronic, nonspecific low back pain of mechanical origin.
  
  
  METHODS
  Von Korff pain and disability (100-point) scales.
  
  
  METHODS
  Patients were randomly allocated to visits (1, 2, 3 or 4 visits/week for 3 weeks) and to treatment regimen (spinal manipulation only or spinal manipulation with PM). All patients received high-velocity low-amplitude spinal manipulation. Half received one or two of the following PM at each visit: soft tissue therapy, hot packs, electrotherapy or ultrasound.
  
  
  RESULTS
  Pain intensity: At 4 weeks, there was a substantial linear effect of visits favoring a larger number of visits: 5.7 points per 3 visits (SE=2.3, p=.014). There was no effect of treatment regimen. At 12 weeks, the data suggested the potential for a similar effect of visits on patients receiving both manipulation and PM. Functional disability: At 4 weeks, a visits effect was noted (p=.018); the slope for group means was approximately 5 points per 3 visits. There were no group differences at 12 weeks.
  
  
  CONCLUSIONS
  There was a positive, clinically important effect of the number of chiropractic treatments for chronic low back pain on pain intensity and disability at 4 weeks. Relief was substantial for patients receiving care 3 to 4 times per week for 3 weeks.
authors.affiliation: Center for Outcome Studies, Western States Chiropractic College, 2900 NE 132nd Avenue, Portland, OR 97230, USA. mhaas@wschiro.edu
authors.forename: Mitchell
authors.initials: M
authors.lastname: Haas
authors.forename: Elyse
authors.initials: E
authors.lastname: Groupp
authors.forename: Dale F
authors.initials: DF
authors.lastname: Kraemer
mesh_terms: D000328:Adult; D000368:Aged; D002684:Chiropractic; D002908:Chronic Disease; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000628:therapy*; D008297:Male; D020393:Manipulation, Spinal; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome