The vast majority of academic and government research has uncovered little evidence that health care providers run more tests due to liability concerns; rather, patient safety or profit motives are the real reasons for conducting medical procedures. That key finding is from a new white paper by the American Association for Justice (AAJ) exploring a topic that has been subjected to myths and distortions during the health care debate.

The Congressional Budget Office called the evidence of defensive medicine “not conclusive,” and summarized, “On the basis of existing studies and its own research, CBO believes that savings from reducing defensive medicine would be very small.”i Researchers at Dartmouth College echoed these conclusions, saying, “The fact that we see very little evidence of widespread physician exodus or dramatic increases in the use of defensive medicine in response to increases in state malpractice premiums places the more dire predictions of malpractice alarmists in doubt.”ii

The Government Accountability Office (GAO) has issued similar statements questioning the occurrence of defensive medicine, saying, “the overall prevalence and costs of [defensive medicine] have not been reliably measured,” and “study results cannot be generalized to estimate the extent and cost of defensive medicine practices across the health care system.”iii The GAO reported that even “officials from AMA [American Medical Association] and several medical, hospital, and nursing home associations…told us that defensive medicine exists to some degree, but that it is difficult to measure.”iv

To the extent that defensive medicine does exist, research has found that the motivation behind it is not liability but rather a desire to simply help a patient or, in some cases, boost physician income. One government agency found that doctors chose not to order any tests or diagnostic procedures 95 percent of the time. Doctors who ordered tests almost always did so because of medical indications, and only one half of one percent of all cases involved doctors who ordered tests due solely to medical negligence concerns.v

Doctors may actually practice “defensively” because it generates more income, according to the GAO. They identified “revenue-enhancing motives” as one of the real reasons behind the utilization of extra diagnostic tests and

In Florida, health authorities determined diagnostic-imaging centers and clinical labs were ordering additional tests because the majority were physician-owned and the tests provided a lucrative stream of income. Federal law now prohibits the referral of Medicare patients to certain physician-owned facilities, many of which charge double the amount in lab fees.vii As Mello and colleagues commented, “In medicine practiced as a business, defensive medicine is understood and may even be profitable.”viii

Nor is defensive medicine necessarily bad medicine. The CBO, in its analysis, recognized that there was a financial incentive but also identified health benefits to patients: “so-called defensive medicine may be motivated less by liability concerns than by the income it generates for physicians or by the positive (albeit small) benefits to patients.”ix Researchers at Tulane University found similar benefits to patients.x Their analysis of the National Practitioner Databank and the Nationwide Inpatient Sample (NIS) found that increased medical negligence risk was associated with an improvement in mortality, and concluded that the idea that defensive medicine had no positive effect on patients was untrue.

i Limiting Tort Liability for Medical Malpractice, Congressional Budget Office, January 8, 2004; see also Budget Options, Volume I, Health Care, Congressional Budget Office, December, 2008.
ii Katherine Baicker and Amitabh Chandra, The Effect of Malpractice Liability on the Delivery of Health Care, National Bureau of Economic Research, Working Paper, 10709, 2004.

iii Medical Malpractice: Implications of Rising Premiums on Access to Health Care, Governament Accountability Office, September 29, 2003,

iv Ibid.

v Alexee Deep Conroy, Lessons Learned from the ‘Laboratories of Democracy’: A Critique of Federal Medical Liability Reform, Cornell Law Review 1159, 1176, 2006.
vi Medical Malpractice: Implications of Rising Premiums on Access to Health Care, Governament Accountability Office, September 29, 2003,

vii Janice Castro, Condition: Critical, Time, June 24, 2001; See also John K. Iglehart, The Emergence of Physician-Owned Specialty Hospitals, New England Journal Of Medicine, 2006.

viii Troyen A. Brennan, Michelle M. Mello, and David M. Studdert, Liability, Patient Safety, and Defensive Medicine: What Does the Future Hold? Medical Malpractice and the U.S. Health Care System, Cambridge University Press, 2006.

ix Limiting Tort Liability for Medical Malpractice, Congressional Budget Office (CBO), January 8, 2004.
x Praveen Dhankhar, M. Mahmud Khan, Shalini Bagga, Effect of Medical Malpractice on Resource Use and Mortality of AMI Patients, Journal of Empirical Legal Studies, Volume 4, Issue 1, March 21, 2007.