J Manipulative Physiol Ther 2000 (May); 23 (4): 225—230
Guy Hains, DC, François Hains, DC
Private practice of chiropractic, Trois-Rivières, Quebec, Canada
OBJECTIVES: To provide preliminary information on whether a regimen of 30 chiropractic treatments that combines ischemic compression and spinal manipulation effectively reduces the intensity of pain, sleep disturbance, and fatigue associated with fibromyalgia. In addition, to study the dose-response relation and identify the baseline characteristics that may serve as predictors of outcome.
DESIGN: Subjects were assessed with self-administered questionnaires taken at baseline, after 15 and 30 treatments, and 1 month after the end of the treatment trial.
SETTING: Private practice. METHODS: Participating subjects were adult members of a regional Fibromyalgia Association. Participating subjects had fibromyalgia for more than 3 months. They received 30 treatments including ischemic compression and spinal manipulation. The 3 outcomes being evaluated were pain intensity, fatigue level, and sleep quality. A minimum 50 improvement in pain intensity from baseline to the end of the treatment trial was needed to include the patient in the respondent category.
RESULTS: Fifteen women (mean age 51.1 years) completed the trial. A total of 9 (60) patients were classified as respondents. A statistically significant lessening of pain intensity and corresponding improvement in quality of sleep and fatigue level were observed after 15 and 30 treatments. After 30 treatments, the respondents showed an average lessening of 77.2 (standard deviation = 12.3) in pain intensity and an improvement of 63.5 (standard deviation = 31.6) in sleep quality and 74.8 (standard deviation = 23. 1) in fatigue level. The improvement in the 3 outcome measures was maintained after 1 month without treatment. Subjects with less than 35 improvement after 15 treatments did not show a satisfactory response after 30 treatments. A trend, determined as not statistically significant, suggests that older subjects with severe and more chronic pain and a greater number of tender points respond more poorly to treatment.
CONCLUSION: This study suggests a potential role for chiropractic care in the management of fibromyalgia. A randomized clinical trial should be conducted to test this hypothesis.
From the Full-Text Article:
The results of this study suggest that chiropractic care combining ischemic compression and spinal manipulation may help patients with fibromyalgia. A total of 60% of this sample reported a mean improvement of 77.1% in pain intensity in addition to a 63.5% improvement in the quality of sleep and a 74.8% improvement in fatigue level. The causes of poor quality of sleep and high fatigue levels reported in fibromyalgia are poorly understood. The observed improvement in this study may suggest that these symptoms were aggravated, at least in part, by the presence of pain. The reduction of pain may have led to the improvement in the quality of sleep and fatigue observed in this study. These symptoms may be part of a vicious cycle caused by pain. [6, 7]
The lessening of pain was maintained throughout the follow-up period of 1 month, suggesting that chiropractic care may help patients beyond the actual provision of care. This effect was not observed in the different drug trial, which tested the efficacy of amitriptyline and cyclobenzaprine for the treatment of fibromyalgia.  These drugs were not shown to be effective after stopping medication intake.
Side effects were not monitored during the trial. However, compliance was excellent, and no patient dropped out of the treatment section of the study. This compliance suggests that patients were satisfied with the care received and did not have side effects or complications sufficiently intense for them to withdraw from the study. The opposite problem was encountered; two subjects in the nonrespondent group requested to continue treatment during the 1-month follow-up period because of a recurrence of the original symptoms. For ethical reasons, these patients were excluded from the follow-up section of the study and remained under active care.
Previous drug trials with fibromyalgia have reported a strong placebo response. [15, 22, 23] The decision to require a minimum 50% improvement after 30 treatments to classify subjects as respondents was an attempt to exclude subjects whose response to treatment was more likely to be attributed to this effect. On its own, such a placebo effect would be unlikely to produce the magnitude of improvement noted in this group of respondents and even less likely to produce a sustainable improvement 1 month after the end of the treatment trial. In addition, the more treatment patients received, the less symptoms they reported. This dose-response relation supports the hypothesis that the observed improvement may be caused by the physiologic effect of the treatment itself. 
Cost effectiveness is important when considering the use of a new treatment approach. This sample showed a progressive improvement in outcome during the treatment trial, suggesting that the course of 30 treatments was adequate. The sustaining of the effect at the 1-month follow-up assessment also suggests that this chiropractic approach may have a prolonged benefit.
It may also be possible to identify which patients are most likely to respond positively to chiropractic care. In our sample, some not statistically significant trends that warrant attention in a larger clinical trial were observed. For instance, older subjects with a more chronic illness and a greater intensity of symptoms who have more tender points at baseline assessment appeared to respond more poorly to treatment. In addition, the percent lessening of pain intensity after 15 treatments was significantly inferior in the nonrespondents. Subjects who showed > 35% improvement after 15 treatments did not show a satisfactory response after 30 treatments. This observation suggests that a minimum 35% improvement in pain intensity must be observed after 15 treatments or it may no longer be appropriate to pursue this form of treatment.
A selection bias may have occurred because subjects volunteered to participate in this study and because of the small sample size. However, the baseline characteristics of our subjects were similar to those in another fibromyalgia trial.  The outcome was strictly measured with self-administered questionnaires to minimize the risk that the physician's expectations might influence the results. Moreover, these questionnaires were completed without the clinician present to limit possible bias related to the desire of the subjects to please the clinician and report an inaccurate improvement. Furthermore, fibromyalgia is a chronic illness that rarely remits, making it unlikely that improvement was related to the natural history of the condition. Although subjects did not report initiating new forms of treatment during the course of the trial, collecting data about the usage of medication, exercise, or other forms of therapy to minimize biases related to cointerventions would have been more appropriate. Finally, the baseline assessment should have included a more rigorous physical and mental health evaluation. For instance, one of the nonrespondents had chronic leukemia and another was psychologically distressed because her daughter had a life-threatening disease. Such conditions may have adversely influenced the effect of treatments.
The small sample size, the use of a single treating physician, and the absence of a control group with appropriate blinding procedures are some of the most significant limitations of this clinical trial. The hypotheses raised in this study need to be tested with a larger sample size, more than one treating physician, and a blinded design. Based on these results and data from drug trials, [15, 22] the sample size requirement of a placebo-controlled randomized clinical trial was estimated at 50 patients per group to be adequate on the basis of an estimated improvement of 50% in the chiropractic group versus 15% in the placebo group. Future studies should be designed with 90% power and a 2-tailed test with a significance level of .05, assuming a 10 dropout rate in future studies.
This study suggests a potential role for chiropractic care in the management of fibromyalgia. Most subjects with fibromyalgia appear to have responded favorably to a course of 30 chiropractic treatments including spinal manipulation and ischemic compression therapy. Fifteen treatments seem to be an adequate cutoff point to determine if a significant improvement in pain has occurred and if further care is warranted. Chiropractic care appears to provide benefits for at least 1 month after stopping therapy. A placebo-controlled randomized clinical trial is recommended in the near future to test these hypotheses.