title: Regional Supply of Chiropractic Care and Visits to Primary Care Physicians for Back and Neck Pain.
abstract: BACKGROUND
  Whether availability of chiropractic care affects use of primary care physician (PCP) services is unknown.
  
  
  METHODS
  We performed a cross-sectional study of 17.7 million older adults who were enrolled in Medicare from 2010 to 2011. We examined the relationship between regional supply of chiropractic care and PCP services using Spearman correlation. Generalized linear models were used to examine the association between regional supply of chiropractic care and number of annual visits to PCPs for back and/or neck pain.
  
  
  RESULTS
  We found a positive association between regional supply of chiropractic care and PCP services (rs = 0.52; P <.001). An inverse association between supply of chiropractic care and the number of annual visits to PCPs for back and/or neck pain was apparent. The number of PCP visits for back and/or neck pain was 8% lower (rate ratio, 0.92; 95% confidence interval, 0.91-0.92) in the quintile with the highest supply of chiropractic care compared to the lowest quintile. We estimate chiropractic care is associated with a reduction of 0.37 million visits to PCPs nationally, at a cost of $83.5 million.
  
  
  CONCLUSIONS
  Greater availability of chiropractic care in some areas may be offsetting PCP services for back and/or neck pain among older adults.
authors.affiliation: From the University of Michigan, Ann Arbor (MAD, OY); and the Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Geisel School of Medicine, Hanover, NH (MAD, DJG, JPWB). mattadav@umich.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Davis
authors.affiliation: From the University of Michigan, Ann Arbor (MAD, OY); and the Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Geisel School of Medicine, Hanover, NH (MAD, DJG, JPWB).
authors.forename: Olga
authors.initials: O
authors.lastname: Yakusheva
authors.affiliation: From the University of Michigan, Ann Arbor (MAD, OY); and the Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Geisel School of Medicine, Hanover, NH (MAD, DJG, JPWB).
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Gottlieb
authors.affiliation: From the University of Michigan, Ann Arbor (MAD, OY); and the Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth College, Geisel School of Medicine, Hanover, NH (MAD, DJG, JPWB).
authors.forename: Julie P W
authors.initials: JP
authors.lastname: Bynum
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001416:Back Pain / Q000628:therapy*; D003430:Cross-Sectional Studies; D005260:Female; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D016014:Linear Models; D008297:Male; D026882:Manipulation, Chiropractic / Q000706:statistics & numerical data*; D006278:Medicare; D008875:Middle Aged; D019547:Neck Pain / Q000628:therapy*; D011320:Primary Health Care / Q000706:statistics & numerical data*; D014481:United States
keywords: Back Pain; Complementary Medicine; Primary Health Care