Interactions between patients and healthcare providers may have a significant impact on a patient's response to therapy. In this study, patients with osteoarthritis (OA) of the knee will receive either acupuncture or sham acupuncture. The acupuncturists will be trained to interact with the patients in specific ways. The study will evaluate those interactions.

This study will examine placebo responses in the context of practitioner-patient interactions at the time of the encounter. Phase 1 of this study identified patient-related determinants of placebo response, such as beliefs and expectations toward treatment of knee OA with acupuncture. Phase 2 of the study evaluated an assessment tool to measure these determinants. Phase 3 of the study is a randomized controlled trial to evaluate whether placebo effects in patients with knee OA can be enhanced by the acupuncturists' communicative style, which can affect a patient's cognitive expectancies and beliefs.

Patients will initially be randomized to one of two groups, each with a different model for practitioner-patient interaction. Acupuncture practitioners will be trained to follow semi-structured communicative styles, including traditional approaches in Chinese medicine and techniques previously described in patient-doctor communications studies. Within each of these groups, patients will be further randomized to receive either acupuncture or sham acupuncture. Patients will have 6 weeks of biweekly treatment visits. Patients will be followed for 6 months. Visits will be weekly during the first 6 weeks of the study and monthly thereafter.

The study will also include a natural cohort group composed of patients on a study waiting list; these patients will be offered acupuncture 3 months after study entry.

Inclusion Criteria:

• OA diagnosis according to the American College of Rheumatology criteria
• Pain in the knee of at least 3 or more on a 0 to 10 scale (0 none, 10 extreme pain) within 2 weeks prior to study entry
• Stable treatment with anti-inflammatory and analgesic medications during the month prior to study entry
• If receiving glucosamine, stable dosage for 2 months prior to study entry
• Adequate cognitive status as determined by the study officials
• Living in the community
• Ability to communicate in English without a translator
• Access to a telephone

Exclusion Criteria:

• Other diagnosed joint diseases, such as rheumatoid arthritis
• Previous treatment with acupuncture (for any condition)
• Intra-articular injections in the knee in the 2 months prior to study entry