When Research Challenges Our Assumptions

By Daniel Redwood 

When new research, research reviews or practice guidelines support our current beliefs and practices, enthusiasm comes easily. When the 2007 medical practice guidelines on low back pain (LBP) jointly prepared by the American Pain Society and the American College of Physicians recognized spinal manipulation as the only non-pharmacologic method providing “proven benefits” for acute LBP and as one of several methods (including exercise, rehabilitation, acupuncture and yoga) proven effective for chronic LBP, the American Chiropractic Association and doctors of chiropractic (DCs) everywhere welcomed this as a long-overdue recognition of the value of our primary treatment methods.

But when research challenges our assumptions, our responses are understandably mixed. Such findings, if confirmed in multiple studies, may create pressure to change our practice patterns or threaten reimbursement from insurance companies. Like members of other health professions, DCs do not find such developments pleasant. How we and members of other health professions respond to such research says a great deal about who we are, how fully we practice what we preach, and the depth of our commitment to providing the best possible care to our patients.

In recent years, new studies on the effectiveness and cost-effectiveness of central aspects of chiropractic care (particularly spinal manipulation and exercise) have brought a mixture of welcome and challenging news. In a previous ACA News article,1 I described many of the studies showing clear benefits from spinal manipulation and chiropractic care.

It is equally important for us to be familiar with research that challenges us. Fathoming its meaning and charting a course for how best to respond sometimes requires us to face difficult facts and thoroughly ponder their implications. Just as social change is far more sustainable when it percolates up from the grassroots rather than being imposed in a top-down fashion, practice or policy changes necessitated by research are ultimately better integrated and more longlasting if they grow organically from our own enlarged understanding, rather than being forced upon us by external powers we may perceive as hostile. Particularly in the United States, where practice guidelines are voluntary, our willingness to engage this sometimes difficult process is crucial to fulfilling our responsibilities to our patients.

Using recent examples of research that challenges DCs, along with other research that challenges medical physicians, insurers and policy makers, let’s explore this rocky terrain, starting with two 2012 studies from researchers at Northwestern University of Health Sciences (NWUHS) and the Berman Center for Outcomes and Clinical Research.

1 Manipulation Yields Better Pain Outcomes than Medication for Acute and Subacute Neck Pain, with Results Essentially Equivalent to Home Exercise Plus Advice (Bronfort et al., Annals of Internal Medicine, 2012)2
Over the past two decades, there have been several head-to-head randomized trials in which chiropractic care achieved outcomes superior to those of conventional medicine. For LBP, the 1990 Meade et al. study,3,4 published in the British Medical Journal, the flagship journal of the British Medical Association, was arguably the most influential. For headaches, the award-winning5 Boline et al. trial,6 published in the Journal of Manipulative and Physiological Therapeutics in the mid-1990s, still stands out as a noteworthy model for rigorous research structured in a pure chiropractic-versus-medicine format. Had the 2012 Bronfort et al. trial2 been structured similarly, the take-home message would have been received with unalloyed satisfaction by DCs, since the spinal manipulation group fared significantly better on pain reduction (the primary outcome) than the group treated with medication (NSAIDs, acetaminophen or both).

However, in the 15-plus years since Boline’s study and the 20-plus years since Meade’s, chiropractic investigators and their counterparts in other professions have expanded the range of the musculoskeletal pain research agenda. Particularly with back and neck pain, which Dr. Scott Haldeman has described (along with headaches) as “the mainstay of chiropractic practice,”7 the focus now extends beyond comparing spinal manipulation with placebo and, in an increasing number of cases, beyond head-to-head comparisons with standard medical care. In part, this is because the hegemonic cultural authority of primary medical care for musculoskeletal disorders has eroded,8-11 thus necessitating use of a broader set of comparisons.

Broad Implications of a Level Playing Field
The erosion of medical authority in the musculoskeletal arena, however, does not automatically translate into its replacement by chiropractic. In the democracy of science, where equal opportunity is enjoyed by all and all hypotheses are innocent until proven guilty, conventional medicine must prove itself under the same rules applied to others, with no special privileges. But the leveling of the playing field continues across the board. Just as medical approaches are not assumed to be superior to those employed by DCs, neither chiropractic nor medical methods are presumed to be superior to exercise, patient education and advice, or “doing nothing.”

Such changes in the research landscape have broad implications. Bronfort’s 2012 paper,2 published in the influential Annals of Internal Medicine, illustrates the challenges they pose. The researchers began with the hypothesis that “spinal manipulation therapy (SMT) is more effective than medication or home exercise with advice (HEA) for acute and subacute neck pain.” And indeed, when the dust settled, the neck-pain patients receiving spinal manipulation had achieved significantly more pain relief than those receiving medication. However, a third group that received a few instructional sessions of home exercise advice achieved results that were, for all practical purposes, equal to the manipulation group. Despite the fact that a New York Times article about this study was published under the headline “For Neck Pain, Chiropractic and Exercise Are Better Than Drugs,”12 a closer analysis leads to a far more guarded set of conclusions.

Regarding adverse side effects, Bronfort et al. informed that while “the frequency of reported side effects was similar among the three groups (41 to 58 percent), the nature of the side effects differed, with participants in the SMT and HEA groups reporting predominantly musculoskeletal events and those in the medication group reporting side effects that were more systemic in nature. Of note, participants in the medication group reported higher levels of medication use after the intervention.” Also worth noting is that the medication group reported the most side effects and the manipulation group the least.

Before further evaluating the impact of the Bronfort et al. trial, let’s examine another study by the same group, published in Spine a few months later.

2 With or Without Spinal Manipulation, Intensive Supervised Exercise Yields Pain Outcomes Superior to Home Exercise (Evans et al., Spine, 2012)13
The second early 2012 neck pain research article from the NWUHS team (again in collaboration with the Berman Center) looked at chronic neck pain, in contrast to the Bronfort et al. study on acute and subacute neck pain. In the chronic neck pain project, Evans et al.13 compared two different exercise regimes: “high-dose” supervised exercise and “low-dose” home exercise. In addition, they divided the high-dose exercise group in half, with one subgroup also receiving chiropractic spinal manipulation, while the other was treated solely with intensive exercise. Unlike the Bronfort et al. trial, there was no medication group randomized to receive medication as a primary treatment.

All groups showed improvement, with the two supervised strengthening groups improving significantly more than the home exercise group. From the DC’s perspective, the key finding (aside from the effectiveness of exercise for chronic neck pain) is that “no significant differences were found between supervised exercise with or without spinal manipulation, suggesting that spinal manipulation confers little additional benefit.” The authors appropriately note that this finding “differs from the conclusion of the Task Force on Neck Pain and Its Associated Disorders14 and systematic reviews,115,16

which found an advantage for exercise combined with manual therapy for chronic neck pain,” adding, “Importantly, our study was not designed to assess the effect of spinal manipulation alone. A recent Cochrane systematic review has found limited evidence to support spinal manipulation alone for the short-term relief of chronic neck pain.”17

Taken together, the neck pain studies by Bronfort et al. and Evans et al. portray a current situation in which exercise may be emerging as the most effective means of treating neck pain. How does a mature chiropractic profession respond to these two neck pain studies that sharply challenge claims that spinal manipulation is the best means for managing neck pain, and even call into question its value as a standard adjunctive approach when applied together with exercise therapy?

First, it should go without saying that a mature profession, acting in the best interests of its patients, does not attack the messenger, but instead grants the message the thoughtful consideration it clearly merits. Second, exercise is included in the DC’s scope of practice everywhere; this evidence should motivate every DC to stay fully up-to-date on neck pain exercise protocols and to implement these with all patients unless there are specific contraindications. Third, the fact that two randomized trials have found that manipulation adds no benefit to exercise for most neck pain patients does not mean that a substantial benefit will not occur in individual cases. All DCs have seen such cases. How this combination of factors will play out in future chiropractic practice guidelines is at this point unknown.

3 Health Maintenance Care for Injured Workers: Chiropractic Yields Lower Recurrence Rate Than Medicine or Physical Therapy, But Only Slightly Better Than No Treatment (Cifuentes et al., 2011, Journal of Occupational and Environmental Medicine).18,19 In one of the most intriguing and challenging LBP studies to emerge in recent years, researchers at the Center for Disability Research at the Liberty Mutual Research Institute for Safety, led by Manuel Cifuentes, MD, PhD, explored the effectiveness of various approaches— from medicine, physical therapy and chiropractic—for the prevention of injury recurrence when “health maintenance care” is provided to workers who have returned to their jobs after a work-related low back injury.18 Their findings, published in the Journal of Occupational and Environmental Medicine, offer practitioners, insurers and policy makers much food for thought.

Cifuentes and colleagues define health maintenance care as “a clinical intervention approach thought to prevent recurrent episodes of LBP… it blends the public health concepts of secondary prevention (treatment and prevention of recurrences) with tertiary prevention (obtaining the best health condition while having an incurable disease). Health maintenance care can include providing advice, information, counseling and specific physical procedures. Health maintenance care is predominantly and explicitly recommended by DCs, although some physical therapists also advocate health maintenance procedures to prevent recurrences.”

Significantly Fewer LBP Recurrences With Chiropractic Than With Medicine or PT
This extensive review of workers’ compensation data on 894 patients (68 percent male, average age 41) focused on calculating the “hazard ratio of disability recurrence.” Essentially, the question the investigators asked was this: Are patients who receive health maintenance care more likely to experience another episode of disabling low back pain if they are seen by a medical physician, a physical therapist or a DC?

The data were clear: After controlling for demographics and severity, patients treated by DCs were significantly less likely to have a disabling recurrence than those treated by medical doctors or physical therapists. Because chiropractic care fared best, its hazard ratio (HR) was used as the reference point (1.0). In comparison, the HR was 1.6 for MDs and 2.0 for PTs. However, the HR for those not receiving any health maintenance care after they returned to work was 1.2, which was described as similar to the HR for chiropractic in terms of statistical significance.

What are we to make of this? In their discussion section, the researchers do their best to extract meaningful conclusions and policy recommendations from their findings, yet find themselves in a vast sea of uncertainty. First, they confront the one unavoidable conclusion from their data—that once injured workers are back on the job, it would be best to steer them away from further treatments by practitioners whose work has now been associated with a relative increase in the likelihood of disability recurrence. Indeed, Cifuentes’ team explicitly states that one of the plausible mechanisms that might explain the superior outcomes for those receiving chiropractic care in the maintenance phase of recovery is that going to a DC, in effect, keeps patients away from treatments (e.g., MDs and PTs) that may actually make recurrence more likely.

As they struggle to come to terms with the scientific and policy challenges posed by their findings, Cifuentes et al., to their credit, delve deeply into the nature of the chiropractic care—not just spinal manipulation, but the entire DCpatient interaction. They ask whether something else, beyond just giving patients a reason to avoid ineffective treatments from other types of practitioners, is at work.

“… chiropractors argue that their aim is to provide care while being centered on the whole patient. It is possible that this approach provides more opportunities for a provider-patient relationship that improves communication, and likely emphasizes the importance of return to work over symptom control, and focuses on psychosocial issues that have been demonstrated to be important in the evolution of LBP disability.20 Some of the important weakness of this hypothesis is the fact that we are attributing to a whole job title attributes that vary among individual providers. Do chiropractors truly emphasize in their practice relationship quality and communication? Do patients of non-chiropractor providers who focus on personal relationship and good communication have better health outcomes than those patients whose providers do not do so? Some studies seem to point in that direction.21In addition, it is important to state that this considered mechanism is not at all a chiropractor exclusivity and other care providers may similarly think along these lines. Naturalistic studies that focus on the actual experiences of the provider-patient relationships could help to test our proposed mechanisms.”

At this point the discussion has entered new territory, of a kind almost certainly not anticipated when this study was conceived. It has expanded beyond the already important outcomes data to encompass a profoundly promising line of inquiry that goes to the heart of who DCs are, what we believe about the nature of healing and the doctor-patient relationship, and the extent to which these beliefs, when put into practice, yield measurably superior outcomes. That is a discussion DCs should be very happy to hold, both inside and outside the profession. It represents a possible basis not only for greater recognition of chiropractic’s benefits, but also for demonstrating to others in the healing arts the broader value of insights we have attained over our 115-year history. In so doing, we may even help those in other professions to enlarge and clarify their own philosophical perspectives.

4 Shooting the Messenger: The U.S. Preventive Services Task Force and Those Who Attack Its Evidence-Based Recommendations222, 23
All licensed health professions accept in principle that health care should be evidence-based. Elected and appointed officials at all levels of government profess to accept the evidence-based model. Health-advocacy organizations of all types spend much of their time urging health policy makers to fund increased research and to apply its findings.

Undergirding this broad framework, there is presumed to be a shared understanding that: (1) where evidence exists, it should be evaluated by experts without conflicts of interest; (2) reports from such experts should play a central role in formulating public policy; (3) in some cases, available research is insufficient to use as the primary basis for clinical decision making and public policy, and; (4) in all cases, doctors can and should apply professional judgment as a significant part of the equation, balancing risks and benefits for each individual patient and also giving consideration to the patient’s values and preferences.

When New Evidence Conflicts With Past Practice

The massive firestorm that erupted in November 2009, following the release of the U.S. Preventive Services Task Force (USPSTF) report on breast cancer screening, indicates that in many cases, people endorse the evidence-based model only if it supports their preconceived ideas, policies or bottom line.

The USPSTF panel is an independent group of 16 experts who specialize in prevention and primary care, appointed by the Agency for Healthcare Research and Quality. Members are not supposed to have any conflicts of interest on topics they evaluate (as would, for example, an officer or member of an organization representing radiologists who perform mammograms). Furthermore, the USPSTF was expressly charged not to consider issues of cost-effectiveness, only health benefits versus health risks. As reported in the New York Times,24 “in order to formulate its guidelines, the task force used new data from mammography studies in England and Sweden and also commissioned six groups to make statistical models to analyze the aggregate data.”

The six groups of experts, working with separate models, apparently did a thorough job and arrived at remarkably consistent findings, mirroring recommendations of the World Health Organization and many European nations— that regular screenings for all women should begin at age 50 rather than 40, and that it be performed every other year, rather than annually. This would mark a significant change in current U.S. policy, which now recommends that all women receive mammograms once a year starting at age 40.

How Do We Decide?

Most of the negative reactions to the new guidelines focus on one key point: Saving every life is important and therefore we must do everything possible to ensure that no case of breast cancer eludes detection.

The data analysis used to determine whether mammograms should be recommended for all women starting at age 40 or 50—and whether to recommend mammograms once a year, once every other year or at some other interval—goes beyond the scope of this article. But the methods we use to reach such decisions are something that people on all sides of the controversy need to consider. Unless our society can arrive at a consensus on the proper way to make these policy decisions, we will continue talking past each other, generating far more heat than light.

So how do we decide? If your desire to avoid even one unnecessary breast cancer death—a most laudable goal— leads you to reject the new guidelines and stick with the “once a year starting at 40” policy, please ask yourself the following question: Would you favor recommending mammograms twice a week for every female starting at age 15? Remember, just like the USPSTF, you cannot consider financial issues, only health effects. Now, assuming you replied that recommending twice-aweek mammograms starting at age 15 is absurd, would you favor a recommendation of four times a year starting at age 20? Once a year or in alternate years starting at 30? 40? 50? And most important, why?

This can be a very instructive exercise. It takes us straight to the nitty-gritty of health benefits (e.g., lives saved) versus health risks (e.g., radiation exposure, false positives that lead to unnecessary surgery, aggressive treatment of tiny malignancies that would have disappeared without intervention, etc.). Anyone who rejects a proposal to perform mammograms twice a week starting at age 15 has acknowledged that some kind of evidence- informed risk-benefit analysis ought to be used in determining guidelines. That’s the purpose of the USPSTF guidelines process.

Last, but by no means least, nothing in the new guidelines requires or even recommends that women, particularly at-risk women, not receive mammograms prior to age 50. The guidelines explicitly recommend that doctors tailor patient care to the needs of their individual patients. The core issue is whether to recommend a nationwide policy under which all women are urged to have mammograms at a certain frequency, and at what age this should begin.

Those who believe in evidence-based health care must be willing to look at new evidence with clear and open minds. The USPSTF breast-cancer screening controversy demonstrates that a great deal of public education is needed before our society can achieve that goal.

5 A Possible Way Forward: The Choosing Wisely Project25
When a coalition of the provider groups that profit most from overuse and inappropriate use of expensive, hightech diagnostics and therapeutics joins together to urge practitioners to cut back on many of these procedures, we should pay attention. When our own profession takes similar steps, these should be encouraged. As reported by National Public Radio:

“In early 2012, nine national medical groups launched a campaign called Choosing Wisely to get U.S. doctors to back off on 45 diagnostic tests, procedures and treatments that often may do patients no good.

Many involve imaging tests such as CT scans, MRIs and X-rays. Stop doing them, the groups say, for most cases of back pain, or on patients who come into the emergency room with a headache or after a fainting spell, or just because somebody’s about to undergo surgery.

The Choosing Wisely project was launched last year by the foundation of the American Board of Internal Medicine. It recruited nine medical specialty societies representing more than 376,000 physicians to come up with five common tests or procedures ‘whose necessity ... should be questioned and discussed.’

The groups represent family physicians, cardiologists, radiologists, gastroenterologists, oncologists, kidney specialists and specialists in allergy, asthma and immunology and nuclear cardiology.

Eight more specialty groups will join the campaign this fall, representing hospice doctors, head and neck specialists, arthritis doctors, geriatricians, pathologists, hospital practitioners, nuclear medicine specialists and those who perform a heart test called echocardiography.

Consumer groups are involved, too. Led by Consumer Reports, they include the AARP, National Business Coalition on Health, the Wikipedia community and eight others.

The effort represents a growing sense that there’s a lot of waste in U.S. health care, and that many tests and treatments are not only unnecessary but harmful.”

This is a most heartening development, but the extent to which it yields significant changes in individual practice patterns remains to be seen.

Along these lines, the chiropractic profession has also taken important steps in recent years to address practice patterns involving overuse and inappropriate use of diagnostic and treatment methods. In part, because all practice guidelines are voluntary in the United States, change here comes slowly. But change is nonetheless occurring, with chiropractic colleges, the Council on Chiropractic Education and the Council on Chiropractic Guidelines and Practice Parameters helping to lead the way.

Over the past two decades, for example, radiology guidelines at American chiropractic colleges have shifted markedly. Student interns can no longer routinely X-ray all patients. For imaging studies to be approved, specific guidelines (such as the Canadian Cervical Spine Rule) must be followed. To justify taking films at the start of care, at least one of a set of well-defined criteria must be present. These criteria include trauma, being over 55 years of age and certain findings in the case history or orthopedic and neurologic tests.

Students now learn that in the absence of such findings, care should proceed without X-rays. If no clinical progress is noted within a few weeks, X-rays can be taken at that time. This is consistent with recognition across the healing arts that ionizing radiation is not benign and must be used carefully.

Those who have practiced this way, but have not previously had clinical guidelines to support this approach, may have had concerns that in an outlier case where something went wrong, they might be accused of having acted negligently by not routinely X-raying every patient. Defensive medicine (or in this case, defensive chiropractic) is not irrational. To help the needed changes in practice patterns extend beyond the student years into the practice years, and to help veteran practitioners move in this direction as well, it would be most helpful if the laws in each state affirmed that doctors following practice guidelines not be held liable, and not be judged negligent, for adverse outcomes in cases where practice guidelines were followed.

As to what should be included in practice guidelines, it’s critical to consider the upside and the downside. Clearly, if every person with LBP received a set of X-rays prior to being treated by a DC or a medical physician, some cases of cancer would be discovered earlier than would otherwise have been the case. Does that justify exposing all patients to ionizing radiation? To answer that question, one needs to know, for instance, how many cases of cancer would be caused by that same number of exposures. If the downside exceeds the upside, guidelines should discourage routine use. That is what has happened in recent years. [Note: the overall decision about X-rays is more complex, with cancer just one of the factors considered.]

Questions such as these do not always yield simple, obvious answers. They frequently generate controversy, as seen in the ongoing furor over the new USPSTF mammography guidelines. Despite an understandable desire to push such issues under the rug, either temporarily or forever, we must address them head-on if we in the healing arts are to live up to our sacred charge—to relieve suffering as much as possible and to cause suffering as little as possible.

References

1. Redwood D. Mightier Than the Sword: Using Research to Promote and Defend Chiropractic. ACA News. September 2011.

2. Bronfort G, Evans R, Anderson AV, Svendsen KH, Bracha Y, Grimm RH. Spinal Manipulation, Medication, or Home Exercise With Advice for Acute and Subacute Neck Pain. Annals of Internal Medicine. Jan 3, 2012;156(1 Part 1):1-10.

3. Meade TW, Dyer S, Browne W, Townsend J, Frank AO. Low back pain of mechanical origin: randomised comparison of chiropractic and hospital outpatient treatment [see comments]. BMJ. 1990;300(6737):1431-1437.

4. Meade TW, Dyer S, Browne W, Frank AO. Randomised comparison of chiropractic and hospital outpatient management for low back pain: results from extended follow up. BMJ. Aug 5 1995;311(7001):349-351.

5. Kjellman GV, Skargren EI, Oberg BE. A critical analysis of randomised clinical trials on neck pain and treatment efficacy. A review of the literature. Scand J Rehabil Med. Sep 1999;31(3):139-152.

6. Boline PD, Kassak K, Bronfort G, Nelson C, Anderson AV. Spinal manipulation vs. amitriptyline for the treatment of chronic tension-type headaches: a randomized clinical trial. J Manipulative Physiol Ther. Mar-Apr 1995;18(3):148-154.

7. Haldeman S, Underwood M. Commentary on the United Kingdom evidence report about the effectiveness of manual therapies. Chiropr Osteopat. Feb 25, 2010;18(1):4.

8. Hartvigsen J, Foster NE, Croft PR. We need to rethink front line care for back pain. BMJ. 2011;342:d3260.

9. Murphy DR, Justice BD, Paskowski IC, Perle SM, Schneider MJ. The Establishment of a Primary Spine Care Practitioner and Its Benefits to Health Care Reform in the United States. Chiropr Man Therap. Jul 21, 2011;19(1):17.

10. Bishop PB, Quon JA, Fisher CG, Dvorak MFS. The Chiropractic Hospital-based Interventions Research Outcomes (CHIRO) Study: a randomized controlled trial on the effectiveness of clinical practice guidelines in the medical and chiropractic management of patients with acute mechanical low back pain. The Spine Journal. 2010;10(12):1055-1064.

11. Redwood D. Chiropractic identity: charting our future roles. Health Insights Today. 2011;4(5). Accessed 6/24/12.

12. O’Connor A. For neck pain, chiropractic and exercise are better than drugs. New York Times. http://well.blogs.nytimes. com/2012/01/03/for-neck-pain-chiropracticand- exercise-are-better-than-drugs/. Accessed 1/3/12.

13. Evans R, Bronfort G, Schulz C, et al. Supervised exercise with and without spinal manipulation performs similarly and better than home exercise for chronic neck pain: a randomized controlled trial. Spine (Phila Pa 1976). May 15, 2012;37(11):903-914.

14. Nordin M, Carragee EJ, Hogg-Johnson S, et al. Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders. Spine. Feb 15 2008;33(4 Suppl):S101-122.

15. Kay TM, Gross A, Goldsmith C, Santaguida PL, Hoving J, Bronfort G. Exercises for mechanical neck disorders. Cochrane database of systematic reviews. 2005(3):CD004250.

16. Gross AR, Goldsmith C, Hoving JL, et al. Conservative management of mechanical neck disorders: a systematic review. J Rheumatol. May 2007;34(5):1083-1102.

17. Gross A, Hoving JL, Haines T. SR. Manipulation and mobilisation for mechanical neck disorders [review] Cochrane Database Syst Rev. 2009(1-91).

18. Cifuentes M, Willetts J, Wasiak R. Health maintenance care in work-related low back pain and its association with disability recurrence. Journal of occupational and environmental medicine/American College of Occupational and Environmental Medicine. Apr 2011;53(4):396-404.

19. Redwood D. Health maintenance care for injured workers. Health Insights Today. 2011;4(4). www.healthinsightstoday.com/articles/ v4i4/edlogThp1.html. Accessed 6/24/12.

20. Shaw WS, Pransky G, Fitzgerald TE. Early prognosis for low back disability: intervention strategies for health care providers. Disability and Rehabilitation. Dec 15, 2001;23(18):815-828.

21. Dasinger LK, Krause N, Thompson PJ, Brand RJ, Rudolph L. Doctor proactive communication, return-to-work recommendation, and duration of disability after a workers’ compensation low back injury. Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine. Jun 2001;43(6):515-525.

22. Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine. 2009;151(10):716-726.

23. Redwood D. Attacking unwelcome evidence. Health Insights Today. 2010;3(1). www.healthinsightstoday. com/articles/v3i1/edlog.html.

24. Kolata G. Panel urges mammograms at 50, not 40. New York Times. Nov 16, 2009.

25. Redwood D. Which procedures are needed? Health Insights Today. 2012;5(3). 

Daniel Redwood, DC, is a professor at Cleveland Chiropractic College–Kansas City. He is the editor-in-chief of Health Insights Today, associate editor of Topics in Integrative Healthcare and a member of the editorial board of the Journal of the American Chiropractic Association. Dr. Redwood’s website and health policy blog are at www.redwoodhealthspeak.com.

 

Published in the September 2012 ACA News.