title: Diagnostic imaging rates for head injury in the ED and states' medical malpractice tort reforms.
abstract: OBJECTIVE
  Physicians' fears of being sued may lead to defensive medical practices, such as ordering nonindicated medical imaging. We investigated the association between states' medical malpractice tort reforms and neurologic imaging rates for patients seen in the emergency department with mild head trauma.
  
  
  METHODS
  We assessed neurologic imaging among a national sample of 8588 women residing in 10 US states evaluated in an emergency setting for head injury between January 1, 1992, and December 31, 2001. We assessed the odds of imaging as it varied by the enactment of medical liability reform laws.
  
  
  RESULTS
  The medical liability reform laws were significantly associated with the likelihood of imaging. States with laws that limited monetary damages (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.40-0.99), mandated periodic award payments (OR, 0.64; 95% CI, 0.43-0.97), or specified collateral source offset rules (OR, 0.62; 95% CI, 0.40-0.96) had an approximately 40% lower odds of imaging, whereas states that had laws that limited attorney's contingency fees had significantly higher odds of imaging (OR, 1.5; 95% CI, 0.99-2.4), compared to states without these laws. When we used a summation of the number of laws in place, the greater the number of laws, the lower the odds of imaging. In the multivariate analysis, after adjusting for individual and community factors, the total number of laws remained significantly associated with the odds of imaging, and the effect of the individual laws was attenuated, but not eliminated.
  
  
  CONCLUSIONS
  The tort reforms we examined were associated with the propensity to obtain neurologic imaging. If these results are confirmed in larger studies, tort reform might mitigate defensive medical practices.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, USA. rebecca.smith-bindman@radiology.ucsf.edu
authors.forename: Rebecca
authors.initials: R
authors.lastname: Smith-Bindman
authors.forename: Charles E
authors.initials: CE
authors.lastname: McCulloch
authors.forename: Alexander
authors.initials: A
authors.lastname: Ding
authors.forename: Alex
authors.initials: A
authors.lastname: Ding
authors.forename: Christopher
authors.initials: C
authors.lastname: Quale
authors.forename: Philip W
authors.initials: PW
authors.lastname: Chu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006259:Craniocerebral Trauma / Q000175:diagnosis* / Q000191:economics; D003675:Defensive Medicine / Q000191:economics / Q000331:legislation & jurisprudence*; D003952:Diagnostic Imaging / Q000191:economics / Q000706:statistics & numerical data*; D005260:Female; D018166:Health Care Reform / Q000331:legislation & jurisprudence; D006801:Humans; D016365:Liability, Legal / Q000191:economics; D016015:Logistic Models; D008318:Malpractice / Q000191:economics / Q000331:legislation & jurisprudence*; D006278:Medicare / Q000191:economics; D012720:Severity of Illness Index; D014481:United States