Research Review By Dr. Michael Haneline©

Date Posted:

February 2010

Study Title:

Chiropractic care for patients with acute neck pain: results of a pragmatic practice-based feasibility study


Haneline M & Cooperstein R

Author's Affiliations:

International Medical University, Kuala Lumpur, Malaysia and Palmer College of Chiropractic West, San Jose, CA USA.

Publication Information:

Journal of Chiropractic Medicine 2009; 8(3):143-155.

Background Information:

Acute neck pain (ANP) is a common condition that has been shown in some studies to affect over 40% of the population. Accordingly, many Chiropractors treat patients with this condition, even though there is little research evidence to support it. It should be noted, however, that no form of treatment has been shown to be clearly effective for this condition and, in general, the condition has not been studied very well. In fact, a systematic review by Vernon et al. (1) concluded that there were very few high-quality clinical trials for any conservative treatments that are commonly used to treat ANP.

There are a variety of reasons why so little research has been carried out on ANP, but mainly it is because acute patients are often in the subacute or chronic stage by the time they are included in a clinical study. Because of this methodology problem, the current study used a practice-based research (PBR) model in order to shorten the delay between patient recruitment and the beginning of chiropractic care. Hence, ANP patients would be much more likely to be in the acute stage when they entered the study.

The purpose of this study was primarily to establish a chiropractic PBR network and to determine the feasibility of using it to investigate chiropractic care for patients with ANP. The current paper mainly reports the study’s treatment outcomes, including pain, disability, and patient satisfaction with the care they received.

Pertinent Results:

  • A total of 99 ANP patients were included in the study; 34 (37.8%) were men and 56 (62.2%) were women; the mean age of the group was 41.6 years.
  • Ten chiropractors actually contributed data, despite the fact that 28 chiropractors agreed to participate. The mean number of cases contributed by the chiropractors was 9.2, but the range was from 1 to 54, which was rather wide. Four of the chiropractors were very active at recruiting subjects, contributing 89% of the total data on the patients.
  • Progressive improvement of all outcome measures was reported at each of the data collection points, except for a slight worsening of the Characteristic Pain Intensity (CPI) score at week 8.
  • Sixty-two (68.9%) of the patients completed the chiropractic care that was initially recommended to them.
  • Only 30% of the ANP episodes were caused by trauma, which were primarily (70% of the cases) related to injuries sustained in automobile collisions.
  • A prior history of neck pain was reported by 54% of the patients and secondary conditions were reported by 62% of them, mainly involving back pain, headache, and/or an upper extremity problem.
  • Very few of the patients were referred to other healthcare providers: 4 to medical doctors and 2 to massage therapists.
  • Patients were overall highly satisfied with their chiropractic care, with 47 out of 49 (96%) of them indicating that they were either “Very satisfied” or “Satisfied” and 98% of them indicating that they “Definitely would” or were “Very likely” to choose chiropractic care again if they ever noticed a similar problem again. Patient satisfaction responses were provided by 49 of the patients.
The chiropractors reported that 7 patients had transient minor adverse effects to chiropractic care; 7.8% of the patients where data was available. Symptoms included:
  • increased neck pain in 5 patients (2 were very mild, 2 mild, and 1 moderate)
  • dizziness in 1 (moderate)
  • the “Other” category was selected in 1 case (mild)
Most of the patients (63) received physical therapy modalities in addition to manipulation, including ultrasound, massage (most commonly used), heat, electrical stimulation, and cryotherapy. Soft tissue techniques (e.g., trigger point therapy) were also commonly used. Further, advice about activities of daily living was given to the majority of patients, especially exercise recommendations.

1,235 distinct cervical spine manipulations were performed, which were mostly carried out with the patient in a supine position. 74% of the manipulations were applied below the level of C4, most commonly at the level of C6.

Clinical Application & Conclusions:

Patient improvements were observed when comparing sequential evaluations on all outcomes and nearly all of the patients who responded to the satisfaction questionnaire were very satisfied or satisfied with their chiropractic care. These results compare favorably with the small number of other studies that have looked at chiropractic care for ANP.

This study’s main conclusion was that the practice-based methodology that was utilized is a feasible way to investigate the management of ANP by chiropractors. That being said, it should be noted that it was very difficult to obtain follow-through from many of the doctors. Recruiting the chiropractors was fairly easy; a number of them expressed interest in participating, enrolled in the practice-based network, and promised to recruit patients.

However, most did not even begin to fulfill their obligation. Only 10 out of 28 chiropractors who initially agreed to participate actually collected and supplied data and most of the data came from just 4 of the chiropractors. As the primary investigator of this study, I urge readers who have the occasion to participate in PBR to do everything in their power to cooperate with the investigators. Many investigators shy away from PBR because of its known difficulties, even though we as a profession could feasibly and economically multiply our research efforts if more PBR studies were carried out.

It is interesting that the rate of adverse effects in this study was only 7.8% in patients where data was available. In contrast, other studies have reported rates up to 6 times higher (2-4). Perhaps some of this difference was due to the way the data were collected. In the current study, the chiropractors reported adverse effects that they observed in their patients, whereas the patients completed questionnaires in the other studies. There are problems with both methods.

For instance, the patients may check off a number of selections in a questionnaire when presented with a laundry list of symptoms. The power of suggestion (response bias) may prompt them to list adverse effects that they wouldn’t otherwise think of. An example is fatigue following manipulation, which is a question asked in some of the above mentioned studies. I have through the years had a number of patients tell me that they felt very relaxed and were able to sleep soundly for the first time in years after their first adjustment. These patients considered these “adverse effects” to be very positive, but they would appear to be negative effects in one of the studies because the patient would have selected the “fatigued” response.

The chiropractor conveying the patient’s adverse effects as was done in the current study may also lead to problems; for instance, the patient may not tell the doctor about minor symptoms, the patient may leave care (possibly related to a severe reaction to treatment), the chiropractor may think that the adverse effect was not related to treatment, etc. The best way to query patients about adverse effects to chiropractic care has not, in my opinion, been devised yet and more studies are certainly needed.

Study Methods:

The chiropractors who participated in this study were recruited using several different methods, including articles in a college alumni publication, presentations at local chiropractic society meetings, and word of mouth.

Acute neck pain patients were recruited by the participating chiropractors chronologically as they presented for care. The patients were included if they fulfilled the following criteria:
  • Presented to a participating chiropractor's office with recent-onset neck pain
  • Generally healthy
  • Between 18 and 71 years of age
  • Consented to participation in the study and signed an informed consent form
Patients were excluded from the study if they had:
  • Severe neck injury
  • Local bone pathology
  • Spine-related surgery
  • Focal neurologic deficit
Each chiropractor used his or her usual protocols in managing the patients’ care. The chiropractors administered various evaluations during the course of patient care for up to 26 weeks, if a patient happened to be under care for that length of time.

The patient outcome measures included:
  • Neck Disability Index (NDI)
  • CPI score (an average value of a 3-part visual analogue pain rating scale that considers current pain, average pain, and pain at its worst)
  • Percentage of time in pain
  • Post-treatment patient satisfaction
In addition to the patient outcome measures, the chiropractors completed a questionnaire following each patient’s discharge that queried about a number of factors including patient demographics, secondary conditions, history of trauma and/or prior neck pain, whether adjunctive therapies were used, total number of patient visits, whether the patient completed their treatment plan, and whether the patient was referred.

Study Strengths / Weaknesses:

This was an observational study that did not include a comparison group of any kind. The patients’ improvements could therefore have been due to natural progression of the condition, placebo effects, Hawthorne effects, or confounding variables.

This was a pragmatic study in that each patient was provided different treatment modalities according to the usual routine of the participating chiropractors. Patients were thus under care over different durations and frequencies, which caused the group to become smaller at each follow-up evaluation.

It should be noted that the participating chiropractors were not compensated in any way; also, they had to administer study questionnaires and complete various tasks in addition to their usual duties, which may have interfered with their usual practice flow and could have compromised patient follow-up. They were trained on the study protocols and the importance of patient follow-through; however, the data collection process was ultimately their responsibility.

Final patient questionnaires, which gathered information on satisfaction with care, were only returned in about ½ of the cases. Patients who did not respond may have had a more negative outlook on their care than those who did respond, which could have made patient satisfaction look better than it really was. On the other hand, the patients sealed their study questionnaires in an envelope to keep their responses anonymous, which should have reduced acquiescence bias.

Additional References:

  1. Vernon HT, Humphreys BK, Hagino CA. A systematic review of conservative treatments for acute neck pain not due to whiplash. J Manipulative Physiol Ther 2005;28:443-8.
  2. Rubinstein SM, Leboeuf-Yde C, Knol DL, de Koekkoek TE, Pfeifle CE, van Tulder MW. The benefits outweigh the risks for patients undergoing chiropractic care for neck pain: a prospective, multicenter, cohort study. J Manipulative Physiol Ther 2007;30(6):408-418.
  3. Hurwitz EL, Morgenstern H, Vassilaki M, Chiang LM. Adverse reactions to chiropractic treatment and their effects on satisfaction and clinical outcomes among patients enrolled in the UCLA Neck Pain Study. J Manipulative Physiol Ther. Jan 2004;27(1):16-25.
  4. Leboeuf-Yde C, Hennius B, Rudberg E, Leufvenmark P, Thunman M. Side effects of chiropractic treatment: a prospective study. J Manipulative Physiol Ther 1997;20(8):511-515.