title: Impact of imaging guidelines on X-ray use among American provider network chiropractors: interrupted time series analysis.
abstract: BACKGROUND
  Overuse and misuse of spine X-ray imaging for nonspecific back and neck pain persists among chiropractors. Distribution of educational materials among physicians results in small-to-modest improvements in appropriate care, such as ordering spine X-ray studies, but little is known about its impact among North American chiropractors.
  
  
  OBJECTIVE
  To evaluate the impact of web-based dissemination of a diagnostic imaging guideline on the use of spine X-ray images among chiropractors.
  
  
  METHODS
  Quasi-experimental design that used interrupted time series to evaluate the effect of guidelines dissemination on spine X-ray imaging claims by chiropractors enlisted in managed care network in the United States.
  
  
  METHODS
  Consecutive adult patients consulting for complaints of spine disorders.
  
  
  METHODS
  A change in level (the mean number of spine X-ray imaging claims per month immediately after the introduction of the guidelines), change in trend (any differences between preintervention and postintervention slopes), estimation of monthly average intervention effect after the intervention.
  
  
  METHODS
  The imaging guideline was disseminated online in April 2008. Administrative claims data were extracted between January 2006 and December 2010. Segmented regression analysis with autoregressive error was used to estimate the impact of guideline recommendations on the rate of spine X-ray studies. Sensitivity analysis considered the effect of two additional quality improvement strategies, a policy change and an education intervention.
  
  
  RESULTS
  Time series analysis revealed a significant change in the level of spine X-ray study ordering weeks after introduction of the guidelines (-0.01; 95% confidence interval=-0.01, -0.002; p=.01), but no change in trend of the regression lines. The monthly mean rate of spine X-ray studies within 5 days of initial visit per new patient exams decreased by 10 per 1000, a 5.26% relative decrease after guideline dissemination. Controlling for two quality improvement strategies did not change the results.
  
  
  CONCLUSIONS
  Web-based guideline dissemination was associated with an immediate reduction in spine X-ray imaging claims. Sensitivity analysis suggests our results are robust. This passive strategy is likely cost-effective in a chiropractic network setting.
authors.affiliation: School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, 3630 Promenade Sir-William-Osler, Hosmer House, Room 205, Montreal, Quebec H3G 1Y5, Canada; Université du Québec à Trois-Rivières, Trois-Rivieres, Quebec, boul. Des Forges, C. P. 500, Trois-Rivières, Québec G9A 5H7, Canada. Electronic address: andre.bussieres@mcgill.ca.
authors.forename: André E
authors.initials: AE
authors.lastname: Bussières
authors.affiliation: School of Nursing, University of Michigan, 400 N. Ingalls, Ann Arbor, MI 48109-0482, USA; Center for Clinical Management Research, VA Ann Arbor Health Care System, 2215 Fuller Road, Mail Stop 152 Ann Arbor, MI 48105 USA.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Sales
authors.affiliation: Department of Epidemiology and Community Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada; Clinical Epidemiology Program, Ottawa Health Research Institute, 725 Parkdale Ave, Ottawa, Ontario, K1Y 4E9, Canada; Centre for Practice-Changing Research, Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Rd, Box 711, Ottawa, Ontario K1H 8L6, Canada.
authors.forename: Timothy
authors.initials: T
authors.lastname: Ramsay
authors.affiliation: Clinical Quality Management, American Specialty Health Network, Inc, 10221 Waterbridge Circle, San Diego, CA 92121, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Hilles
authors.affiliation: Clinical Epidemiology Program, Ottawa Health Research Institute, 725 Parkdale Ave, Ottawa, Ontario, K1Y 4E9, Canada; Centre for Practice-Changing Research, Ottawa Hospital Research Institute, The Ottawa Hospital - General Campus, 501 Smyth Rd, Box 711, Ottawa, Ontario K1H 8L6, Canada; Department of Medicine, University of Ottawa, Ottawa, Ontario K1H 8L6, Canada.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Grimshaw
mesh_terms: D002684:Chiropractic / Q000592:standards*; D003952:Diagnostic Imaging; D019983:Guideline Adherence / Q000706:statistics & numerical data*; D006300:Health Services Misuse / Q000517:prevention & control; D006801:Humans; D033181:Information Dissemination / Q000379:methods; D020407:Internet; D065186:Interrupted Time Series Analysis; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011859:Radiography / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging*; D014481:United States
keywords: Chiropractors; Health care; Primary care; Quality assurance; Test ordering; Utilization; X-rays