Osteoarthritis (OA) has a major impact on patients' physical functioning and independent mobility (1). Common sites of OA are the knee and the hip (2). The antiinflammatory medications frequently used to treat symptoms of this condition are associated with a number of side effects (3). Furthermore, if these drugs do not lead to adequate response, replacement surgery is often recommended (4).
In recent years, patients with chronic pain have increasingly used acupuncture for relief (5). In a systematic review including 7 randomized controlled trials with a total of 393 patients, acupuncture was shown to be more effective than sham acupuncture in reducing pain, whereas the results regarding joint function were inconclusive (6). Two recent studies, one by Berman et al (7) and one by our group (8), showed some evidence that acupuncture is superior to sham acupuncture in improving function and reducing pain in patients with OA of the knee. The main aim of all of the above-mentioned studies was to determine the efficacy of acupuncture compared with sham acupuncture. To maximize internal validity, these trials used standardized or at least semistandardized acupuncture interventions. In contrast, in routine care a broad variety of acupuncture styles is used, and acupuncture is often administered in conjunction with other treatments. To date there has been little information about the effectiveness of acupuncture treatment provided as an adjunct to routine medical care.
In 2000 the German Federal Committee of Physicians and Health Insurers proposed that large research initiatives on the use of acupuncture for several pain syndromes could be conducted by health insurance companies (9). As one of these research initiatives, we designed the present study as a pragmatic trial to investigate the efficacy of acupuncture in addition to routine care compared with routine care alone in patients with pain due to OA of the knee or the hip. In addition, we examined whether the effects of acupuncture differ in randomized and nonrandomized patients, whether treatment effects last for a period of time after treatment is discontinued, and whether specific patient and physician characteristics are associated with particular treatment outcomes.
Based in part on the results of the present study, the German Federal Committee of Physicians and Health Insurers proposed in April 2006 that acupuncture will be reimbursed by statutory health insurance funds. Pending final decision by the German Ministry of Health, acupuncture will likely be provided as a routine medical option in the treatment of pain due to OA of the knee.
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- PATIENTS AND METHODS
Patients with chronic pain due to OA of the knee or the hip who were treated with acupuncture in addition to routine care showed significant improvements in symptoms and quality of life compared with patients who received routine care alone. In patients who consented to randomization, treatment outcomes after acupuncture were similar to those in patients who declined randomization. Physician characteristics, such as the level of formal acupuncture training or certification, did not influence treatment outcomes.
The present study is by far one of the largest randomized trials of acupuncture to date, including 5% of physicians specializing in acupuncture and a full 1% of all primary care physicians in Germany. The aim of the study was to evaluate acupuncture in a manner that would reflect as closely as possible the conditions of daily medical practice (needle acupuncture and manual stimulation) and maximize external validity. We used recommended outcome parameters to evaluate patients with OA of the knee or the hip (14, 15). Although the study had high followup rates, we used conservative methods to deal with missing data. The additional inclusion of patients who declined randomization allowed us to investigate any potential selection effects.
Obviously, such an approach has methodologic limitations. In this study, neither providers nor patients were blinded with regard to treatment. Although the main outcome was determined based on patient assessment, bias due to lack of blinding cannot be ruled out. To minimize social acceptability bias, all questionnaires were sent directly from and to the coordinating research institute. Because the specifics of both acupuncture treatment and any concomitant interventions were left to the discretion of the physician, treatment regimens varied greatly among patients in our study. Inclusion criteria were broad, which resulted in a heterogeneous patient sample and, possibly, some diagnostic misclassification. While these issues might be considered limitations from an experimental perspective, the study design was chosen to reflect general medical practice. Subgroup analyses in this study showed that the benefit obtained with acupuncture treatment was comparable in patients with OA at different sites, whereas a recent study with naproxen showed a greater reduction of pain in patients with knee OA than in those with hip OA (16).
Patient self-selection in randomized trials of knee OA could be a relevant problem (17). In our study, approximately four-fifths of the eligible patients refused randomization in spite of a (minor) financial incentive, even though the 50% chance of a 3-month delay before starting acupuncture treatment (following an average disease duration of 5 years) presented only a slight disadvantage. These patients were included in the nonrandomized acupuncture group. However, there were no significant differences with respect to either baseline characteristics or treatment outcomes between randomized and nonrandomized patients. Further support for the observation that randomized trials and nonrandomized observational studies could yield similar results is derived from other publications (18). In other study settings in which randomization creates a greater disadvantage (e.g., studies in which control patients receive sham acupuncture), this could be different. Therefore, to control for selection bias, the use of study designs that also include nonrandomized patients appears to be desirable. Both in randomized and in nonrandomized patients in the present study, the improvements in the WOMAC index were clinically relevant (19). A further important finding is that improvements seen immediately after completion of 3 months of acupuncture treatment were sustained for at least another 3 months.
Our results confirm the findings of 3 previous smaller trials (2 randomized [20,21] and 1 nonrandomized ) that compared results in patients receiving acupuncture with results in patients in a waiting-list control group receiving no treatment. Compared with the findings of our recent sham-controlled study (8), improvements in the WOMAC index and the responder rates in the present study were slightly smaller.
Our finding that the physician's formal qualifications and years of acupuncture experience had no significant influence on treatment outcome could be interpreted as a further indication that formal acupuncture training of the clinician has only a limited role in treatment effect. However, these results should be interpreted with caution, because the indicators used in the present study might not adequately reflect the quality of treatment delivered by the physician.
Results of this study provide further evidence that acupuncture is a safe intervention. This is consistent with the findings of previous large surveys (23–25). When interpreting these findings, however, it must be kept in mind that all acupuncture procedures in the present study were administered by physicians.
In conclusion, the present results show that, in patients with chronic pain due to OA of the knee or hip who were receiving routine primary care, addition of acupuncture to the treatment regimen resulted in a clinically relevant and persistent benefit. Acupuncture should be considered as a treatment option for patients with knee or hip OA–associated chronic pain.
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- PATIENTS AND METHODS
We thank Katja Wruck for data management, Iris Bartsch, Beatrice Eden, and Sigrid Mank for data acquisition, and the members of the ARC advisory board (Dr. Konrad Beyer, Dr. Josef Hummelsberger, Hardy Müller, Dr. Albrecht Molsberger, Dr. Helmut Rüdinger, Dr. Wolfram Stör, and Dr. Gabriel Stux) for helpful advice. We also thank all participating physicians and patients.