Wednesday, November 28, 2012

CAM for Chronic Facial Pain Examined

Facial PainChronic and often disabling facial pain associated with temporomandibular joint disorder (TMD) affects more than 10% of adults at any one time and a third of all adults may experience TMD symptoms during their lifetimes. Multiple strategies have been used for pain relief, although no clearly superior evidence-based approach has emerged. A new study compared the efficacy and safety of two different complementary and alternative medicine (CAM) modalities: traditional Chinese medicine and psychosocial-based self-care.

Cheryl Ritenbaugh, PhD, MPH — at the University of Arizona, Tucson — and colleagues constructed a dual-site study to identify the appropriate role for traditional Chinese medicine (TCM; primarily acupuncture and herbs) separately or in conjunction with a practitioner-guided psychosocial self-care (SC) intervention for treating chronic TMD-associated facial pain [Ritenbaugh et al. 2012]. Participants included 168 patients (87% female, 84% white, mean age 43 years) with confirmed TMD.

In a naturalistic design seeking to mimic real-world pain clinic settings, participants entered a stepped-care protocol that began with a basic class explaining TMD and they were then randomized to receive either TCM or SC with experienced practitioners. Then, at weeks 2 and 10, patients receiving SC whose worst facial pain was still above predetermined levels were randomly reallocated to either stay with SC or to receive TCM.

The primary outcome of interest was Characteristic Facial Pain (CFP; an averaging of scores for worst pain, average pain when having pain, and current pain; each assessed on a 0–10 point visual analog scale, or VAS). Secondarily, the researchers assessed on the VAS social activity interference due to the TMD condition.

Writing in the November edition of the Journal of Pain, the researchers reported that TCM provided significantly greater short-term (8-week) pain relief than SC (CFP reduction difference = −0.60; standard deviation of the estimate, or SDE=0.26; P=0.020) and a significantly greater reduction in interference with social activities (−0.81; SDE=0.33; P=0.016). During 16 weeks of therapy, two-thirds of patients allocated throughout the study to TCM experienced a ≥30% improvement in social activity interference, as did patients who first received SC therapy and were later switched at week 8 to TCM.

There were no statistically significant or clinically important differences between TCM or SC in terms of adverse effects. Some TCM participants experienced occasional and mild gastrointestinal disturbances associated with herbal combinations, which were appropriately adjusted. Additionally, acupuncture produced rare, mild, and transient bruising in some patients.

The researchers conclude that their short-term comparative efficacy study of chronic facial pain using a community-based model of treatment delivery suggests that TCM is safe and frequently efficacious alone or subsequent to standard psychosocial interventions. Traditional Chinese medicine is widely available throughout North America, they note, and may provide clinicians and patients with a reasonable addition or alternative to other forms of therapy. However, is TCM truly a clinically significant and important modality for the management of facial pain?

COMMENTARY: This study — funded by the U.S. National Center for Complementary and Alternative Medicine (NCCAM) at the National Institutes of Health — was complex in design, execution, and analysis. The trial attempted to conform with current views of comparative efficacy research by contrasting two viable clinical approaches, measuring clinically meaningful outcomes, and more naturalistically allowing flexibility in the tailoring of therapy to patient needs.

This design was expected to simulate ordinary clinical practice; however, the flexibility of this approach may be its greatest flaw when it comes to estimating the true effectiveness of traditional Chinese medicine (TCM) and/or guided psychosocial self-care (SC). The approach may have fostered numerous uncontrolled or confounding factors from evidence-based perspectives. For example…

  • Conventional treatments for facial pain often include analgesics, anti-inflammatory agents, and antidepressants, “all in use among our participants,” the researchers note. At baseline a mean of 1.7 medications were being taken by patients and this did not significantly change as a result of either CAM therapy. Opioids were used by 13 participants throughout the trial, although the authors do not mention making adjustments for this and other drug use.

  • TCM practitioners could choose from among 65 herbs to tailor treatment and also had considerable latitude in customizing acupuncture protocols and the use of Chinese manipulative therapy (Tuina massage) to serve perceived needs of individual patients.

  • The elaborate psychosocial self-care (SC) intervention included 7 different elements, ranging from education to relaxation and stress management training to what might be considered cognitive-behavioral therapy. The many aspects would seem to lend themselves to considerable variation in delivery of the intervention, customization, and application at home by individual patients.

  • Participants recruited for the study were self-selected volunteers and may have been atypical. The researchers noted higher levels of psychosocial impairment at baseline than expected and many subjects expressed a preference for CAM therapies but had not been able to afford them. This might have biased their responsiveness, particularly to TCM.

  • Possible placebo effects associated with either the TCM or SC intervention were uncontrolled in the trial design and, therefore, not assessed. This could be a considerable deficiency since outcomes may have been strongly influenced by biases in patient selection and the natural course of facial pain.

Looking closer at the data, there also was an interesting statistical phenomenon. Our own calculated standardized effect sizes for TCM vs SC were quite large; 2.31 for facial pain relief (ie, mean difference/standard deviation, or 0.60/0.26), and 2.45 for reduced interference with social activities (0.81/0.33). These large and seemingly important effects were apparently due to the diminutive variance in the data as evidenced by small standard deviations. This is a surprising degree of precision considering the relatively modest sample sizes of each group and potential for inconsistencies in treatment delivery.

At the same time, however, VAS mean scores at the outset (baseline) were moderate for pain (6.5) and mild for social interference (3.3). Absolute reductions in pain and interference attributable to TCM, although statistically significant, were only 9% and 23%, respectively — neither of which might be clinically important to patients.

Clearly, interference with social activities due to facial pain was the more readily affected and ameliorated dependent variable, but it also was the least severe problem at baseline in all participants on average. The fact that two-thirds of patients receiving TCM at some point achieved ≥30% improvement on this variable may not be extraordinary since absolute gains were not very large. Additionally, well under half of patients in any TCM group experienced ≥30% improvements in pain (range 14% to 44%) and, even so, a ≥50% reduction in pain (or at least a 1.2 point improvement on VAS) is often considered to be a minimum clinically significant difference in pain research trials.

Furthermore, as the researchers acknowledge, the modest results of this trial provide information only on relatively short-term outcomes, and longer followup is needed to more adequately assess therapeutic benefits. Overall, the present study would seem to demonstrate the many challenges of comparative efficacy research into CAM therapies that are inherently dependent on practitioner skills in tailoring treatments to individual patient needs. While traditional Chinese medicine showed some promise for chronic facial pain, the outcomes of this trial were not impressive and TCM might be mainly endorsed only for select subgroups of patients that are yet to be determined.

REFERENCE: Ritenbaugh C, Hammerschlag R, Dworkin SF, et al. Comparative Effectiveness of Traditional Chinese Medicine and Psychosocial Care in the Treatment of Temporomandibular Disorders–Associated Chronic Facial Pain. J. Pain. 2012(Nov);13(11):1075-1089 [abstract here].

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