Chiropractic Safety



Study: Chiropractic Does Not Increase Risk of Stroke

A new study finds there is no evidence of excess risk of stroke following chiropractic spinal manipulation, according to a February 2008 report in the journal Spine.  In the study, researchers noted that patients are no more likely to suffer a stroke following chiropractic treatment than they would after visiting their family doctor’s office.

The study goes on to say that any observed association between a vertebrobasilar artery (VBA) stroke and chiropractic manipulation is likely due to patients with an undiagnosed vertebral artery dissection seeking care for neck pain and headache before their stroke.

“This may prove to be one of the most important and significant studies in the profession’s history,” said ACA President Glenn Manceaux, DC. “The results of this study confirm that chiropractic manipulation is a safe and appropriate course of treatment.”

The issue of stroke being associated with a chiropractic neck adjustment focuses around the very rare occurrence of a tear to the vertebral artery as it passes through the sides of the upper cervical vertebrae and into the base of the skull. An injury to the arterial wall may lead to formation of a blood clot, which can break free and travel upward until it lodges in one of the smaller blood vessels in the base of the brain, blocking circulation.

There are many reports in the literature of cervical artery dissections (CADs) occurring after everyday activities that most people would consider non-traumatic, such as turning the head when driving, having your hair washed at a beauty salon, or sleeping on your stomach.

A research paper published in 2001 in the Canadian Medical Association Journal found there is only a one-in-5.85-million risk that a chiropractic neck adjustment will be associated with a subsequent CAD and stroke.

In this new study, the Canadian team looked at nine years of data in Ontario, and found that only 818 patients with a VBA stroke were reported among a population of some 11.5 million people. Unlike a previous study in 2001 that investigated the relationship between chiropractic visits and vertebral artery stroke, researchers in this study also studied visits to family doctors that preceded this kind of stroke.

According to the study’s authors, “Because the association between chiropractic visits and VBA stroke is not greater than the association between PCP visits and VBA stroke, there is no excess risk of VBA stroke from chiropractic care.”  (SEE STUDY BELOW)


Chiropractic: Safer Than Common Pain Medications, Studies Show

Recent news reports on the risks of chiropractic cervical manipulation, or neck adjustments, have needlessly alarmed patients about one of the most safe and effective treatments in health care today, according to the American Chiropractic Association (ACA).

The ACA believes that patients have the right to know about the health risks associated with any type of treatment, including chiropractic. However, health care consumers should be aware that the risks associated with chiropractic treatment are "infinitesimally low," according to Dr. William J. Lauretti, an ACA member and chiropractic researcher from
Bethesda, Maryland. "If you drive about a mile to get to your chiropractor's office, you have a statistically greater chance of being seriously injured in a car accident than of being seriously injured during your chiropractic treatment," explains Dr. Lauretti. "The risks of chiropractic have been grossly exaggerated, and health care consumers need to put these sensationalistic news reports into perspective."

Despite statistics from dozens of studies demonstrating the safety of chiropractic treatments, recent news reports have alleged that chiropractic neck adjustments can frequently damage arteries in the neck that carry blood to the brain, possibly leading to a stroke. However, according to a study by the Rand Corporation, a serious adverse reaction from cervical manipulation occurs less than once in 1 million treatments. The study also showed that on the rare occasion of an adverse reaction, it is often the result of the procedure being performed by a health professional (M.D., P.T.) who is inexperienced or inadequately trained in spinal manipulation, rather than by a licensed doctor of chiropractic. Other scientific textbooks and reports have estimated the risk to be even more minute -- as low as one in 10 million treatments.

During their five-year post-graduate education, doctors of chiropractic are alerted to possible risk factors and taught when to modify their technique or refer a patient for other specialty care. Risk management is also a frequent topic in the continuing education seminars that most states require practicing chiropractors to attend annually.

"Chiropractic researchers have published dozens of studies in recent years that will help chiropractors identify the rare patients who have risk factors," notes Dr. Lauretti. "Studies recently published in the chiropractic literature have found that the risks associated with chiropractic treatments are less than or similar to the risks associated with other conservative treatments often used for similar conditions, such as common prescription and non-prescription medications. Other recently published and ongoing studies are testing the validity of pre-treatment screening tests, and devising strategies for even further minimizing the risks of chiropractic neck treatments." Dr. Lauretti adds that he performs neck adjustments on patients "thousands of times a year" in his practice, and also performs them on his wife and other loved ones. He also frequently receives neck adjustments himself.

When compared to the number of illnesses and deaths that will occur this year from the use of prescription and over-the-counter drugs, the number of serious complications from chiropractic treatment is extremely low. A study published in the April 15, 1998 issue of the Journal of the American Medical Association found that more than 2 million Americans become seriously ill every year from reactions to drugs that were correctly prescribed and taken; 106,000 Americans die annually from those side effects.

Complications from non-steroidal anti-inflammatory drugs (NSAIDs) -- a group that includes prescription and non-prescription pain medications such as aspirin and ibuprofen -- are responsible for 16,500 deaths each year, according to the New England Journal of Medicine. To put this in perspective, approximately 16,500 people died of AIDS in the
United States in 1998, according to the Centers for Disease Control and Prevention.

In addition, a more recent study conducted by the
Institute of Medicine revealed that nearly 100,000 people die each year from medical mistakes made by physicians, pharmacists and other medical professionals.

"The time has come for the medical community and the media to focus their efforts on warning patients about common procedures with very real risks associated with them -- such as the inappropriate use of drugs and surgery," said Dr. Lauretti. "Chiropractic has been proven to be a safe and effective non-drug, non-surgical treatment for a variety of conditions, and tens of millions of satisfied chiropractic patients will attest to this fact."

SOURCE American Chiropractic Association


Medline Articles on Chiropractic Safety


  •  Risk of Vertebrobasilar Stroke and Chiropractic Care: Results of a Population-Based Case-Control and Case-Crossover Study.

Supplementary Research Studies

Spine. 33(4S) Neck Pain Task Force Supplement:S176-S183, February 15, 2008.
Cassidy, J David DC, PhD, DrMedSc *+++; Boyle, Eleanor PhD *;
Cote, Pierre DC, PhD *+++[S]; He, Yaohua MD, PhD *; Hogg-Johnson, Sheilah PhD +[S]; Silver, Frank L. MD, FRCPC [P][//]; Bondy, Susan J. PhD +

Study Design. Population-based, case-control and case-crossover study.

Objective. To investigate associations between chiropractic visits and vertebrobasilar artery (VBA) stroke and to contrast this with primary care physician (PCP) visits and VBA stroke.

Summary of Background Data. Chiropractic care is popular for neck pain and headache, but may increase the risk for VBA dissection and stroke. Neck pain and headache are common symptoms of VBA dissection, which commonly precedes VBA stroke.

Methods. Cases included eligible incident VBA strokes admitted to Ontario hospitals from April 1, 1993 to March 31, 2002. Four controls were age and gender matched to each case. Case and control exposures to chiropractors and PCPs were determined from health billing records in the year before the stroke date. In the case-crossover analysis, cases acted as their own controls.

Results. There were 818 VBA strokes hospitalized in a population of more than 100 million person-years. In those aged <45 years, cases were about three times more likely to see a chiropractor or a PCP before their stroke than controls. Results were similar in the case control and case crossover analyses. There was no increased association between chiropractic visits and VBA stroke in those older than 45 years. Positive associations were found between PCP visits and VBA stroke in all age groups. Practitioner visits billed for headache and neck complaints were highly associated with subsequent VBA stroke.

Conclusion. VBA stroke is a very rare event in the population. The increased risks of VBA stroke associated with chiropractic and PCP visits is likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke. We found no evidence of excess risk of VBA stroke associated chiropractic care compared to primary care.


  • A risk assessment of cervical manipulation vs. NSAIDs for the treatment of neck pain.
    Dabbs V, Lauretti WJ
    J Manipulative Physiol Ther 1995 Oct;18(8):530-6

    OBJECTIVE: We reviewed the literature to evaluate the risk of serious injury or death resulting from cervical manipulation and to assess the evidence that cervical manipulation is an effective treatment for mechanical neck pain. We also reviewed the literature to assess the risks and effectiveness of nonsteroidal anti-inflammatory drugs (NSAIDs), which are often used as the "conventional" first-line treatment for similar musculoskeletal conditions. DATA SOURCES: A series of Medicine literature searches were performed, and materials were reviewed from 1966-1994. Key words included: Chiropractic or Orthopedic Manipulation; Non-Steroidal Anti-Inflammatory Agents; Neck or Back Pain; Randomized Controlled Trials; Adverse Effects. STUDY SELECTION: Studies and literature reviews that provided a numerical estimate of the risk of serious adverse effects or death from cervical manipulation or NSAID use were selected. Also, randomized, controlled studies that evaluated the effectiveness of manipulation or NSAID use for neck pain were included. DATA SYNTHESIS: Although there are a small number of well-performed trials of cervical manipulation for neck pain, we were unable to locate even a single randomized, controlled trial examining NSAID use specifically for neck pain. As for comparative safety, the best available evidence indicates that NSAID use poses a significantly greater risk of serious complications and death than the use of cervical manipulation for comparable conditions. CONCLUSION: The best evidence indicates that cervical manipulation for neck pain is much safer than the use of NSAIDs, by as much as a factor of several hundred times. There is no evidence tha indicates NSAID use is any more effective than cervical manipulation for neck pain.
  • Misuse of the literature by medical authors in discussing spinal manipulative therapy injury.
    Terrett AG. School of Chiropractic and Osteopathy, Faculty of Biomedical and Health Sciences,
    RMIT University, Bundoora, Australia.
    J Manipulative Physiol Ther 1995 May;18(4):203-10

    OBJECTIVE: This study was conducted to determine how the words chiropractic and chiropractor have been used in publications in relation to the reporting of complications from cervical spinal manipulation therapy (SMT). STUDY DESIGN: The study method was to collect recent publications relating to spinal manipulation iatrogenesis which mentioned the words chiropractic and/or chiropractor and then determine the actual professional training of the practitioner involved. METHOD: The training of the practitioner in each report was determined by one of three means: surveying previous publications, surveying subsequent publications and/or by writing to the author(s) of ten recent publications which had used the words chiropractic and/or chiropractor. RESULTS: This study reveals that the words chiropractic and chiropractor commonly appear in the literature to describe SMT, or practitioner of SMT, in association with iatrogenic complications, regardless of the presence or absence of professional training of the practitioner involved. CONCLUSION: The words chiropractic and chiropractor have been incorrectly used in numerous publications dealing with SMT injury by medical authors, respected medical journals and medical organizations. In many cases, this is not accidental; the authors had access to original reports that identified the practitioner involved as a nonchiropractor. The true incidence of such reporting cannot be determined. Such reporting adversely affects the reader's opinion of chiropractic and chiropractors.
  • Is cervical spinal manipulation dangerous?
    Licht PB, Christensen HW, Hoilund-Carlsen PF.Department of Clinical Physiology and Nuclear Medicine, Odense University Hospital, DK-5000 Odense, Denmark.
    J Manipulative Physiol Ther. 2003 Jan;26(1):48-52

    Many M.D.’s frankly discourage the use of cervical manipulation because the fear of an unacceptable high risk. Fortunately, serious complications are rare… Estimations vary from 1 in 400,000 to 1 in 3,000,000 spinal manipulations. In perspective, serious cerebral vascular accidents (CVA’s), after coronary bypass surgery occur in 1.3% & risk assessments have shown that cervical spinal manipulation is several hundred times safer than NSAID’s because of serious gastrointestinal side effects. The rate of hospital errors is also much higher. A review of >30,000 patients showed that iatrogenic disabling injury occurred in 3.7% of cases & 13% were fatal. Major suction lipectomy is considered to have a low complication rate, despite a rate of fatal complications of 1 per 7,500 operations. The fear of CVA’s seems greatly exaggerated in view of the higher rate of complications with many generally accepted medical treatments. It is tempting to speculate that the widespread fear of cervical spinal manipulation within the medical profession is more political that a factual issue. OBJECTIVE: Concern about cerebrovascular accidents after cervical manipulation is common. We report a case of cerebrovascular infarction without sequelae. CLINICAL FEATURES: A 39-year-old man with nonspecific neck pain was treated by his general practitioner with cervical manipulation. INTERVENTION AND OUTCOME: This immediately elicited severe headache and neurologic symptoms that disappeared completely within 3 months despite permanent signs of a complete left-sided cerebellar infarction on computed tomography and magnetic resonance imaging. At 7-year follow-up the patient was fully employed, and repeated magnetic resonance imaging still showed infarction of the left cerebellar hemisphere. However, the patient remained completely free of neurologic symptoms, and color duplex ultrasonography showed normal cervical vessels, including patent vertebral arteries. CONCLUSION: It appears that the risk of cerebrovascular accidents after cervical manipulation is low, considering the enormous number of treatments given each year, and very much lower than the risk of serious complications associated with generally accepted surgery. Provided there is a solid indication for cervical manipulation, we believe that the risk involved is acceptably low and that the fear of serious complications is greatly exaggerated.

·        Inappropriate use of the title chiropractor and term chiropractic manipulation in the peer-reviewed biomedical literature.

            Wenban AB. Chiropr Osteopat. 2006 Aug 22;14(1):16 [Epub ahead of print]


ABSTRACT: BACKGROUND: The misuse of the title chiropractor and term chiropractic manipulation, in relation to injury associated with cervical spine manipulation, have previously been reported in the peer-reviewed literature. The objectives of this study were to - 1) Prospectively monitor the peer-reviewed literature for papers reporting an association between chiropractic, or chiropractic manipulation, and injury; 2) Contact lead authors of papers that report such an association in order to determine the basis upon which the title chiropractor and/or term chiropractic manipulation was used; 3) Document the outcome of submission of letters to the editors of journals wherein the title chiropractor, and/or term chiropractic manipulation, had been misused and resulted in the over-reporting of chiropractic induced injury. METHODS: One electronic database (PubMed) was monitored prospectively, via monthly PubMed searches, during a 12 month period (June 2003 to May 2004). Once relevant papers were located, they were reviewed. If the qualifications and/or profession of the care provider/s were not apparent, an attempt was made to confirm them via direct e-mail communication with the principal researcher of each respective paper. A letter was then sent to the editor of each involved journal. RESULTS: A total of twenty four different cases, spread across six separate publications, were located via the monthly PubMed searches. All twenty four cases took place in one of two European countries. The six publications consisted of four case reports, each containing one patient, one case series, involving twenty relevant cases, and a secondary report that pertained to one of the four case reports. In each of the six publications the authors suggest the care provider was a chiropractor and that each patient received chiropractic manipulation of the cervical spine prior to developing symptoms suggestive of traumatic injury. Regarding two of the four case reports contact with the principal researcher revealed that the care provider was not a chiropractor, as defined by the World Federation of Chiropractic. The authors of the other two case reports did not respond to my communications. Regarding the case series, which involved twenty relevant cases, the principal researcher conceded that the term chiropractor had been inappropriately used and that his case series did not relate to chiropractors who had undergone appropriate formal training. The author of the secondary report, a British Medical Journal editor, conceded that he had misused the title chiropractor. Letters to editors were accepted and published by all four journals to which they were sent. To date one of the four journals has published a correction. CONCLUSIONS: The results of this year-long prospective review suggests that the words chiropractor and chiropractic manipulation are often used inappropriately by European biomedical researchers when reporting apparent associations between cervical spine manipulation and symptoms suggestive of traumatic injury. Furthermore, in those cases reported here, the spurious use of terminology seems to have passed through the peer-review process without correction. Additionally, these findings provide further preliminary evidence, beyond that already provided by Terrett, that the inappropriate use of the title chiropractor and term chiropractic manipulation may be a significant source of over-reporting of the link between the care provided by chiropractors and injury. Finally, editors of peer-reviewed journals were amenable to publishing letters to editors, and to a lesser extent corrections, when authors had inappropriately used the title chiropractor and/or term chiropractic manipulation.