The relationship between patient and practitioner expectations and preferences and clinical outcomes in a trial of exercise and acupuncture for knee osteoarthritis

We investigated the relationship between patient and therapist preferences and expectations and clinical outcomes in a trial of exercise and acupuncture for clinical knee osteoarthritis. 352 Patients were randomised to advice and exercise or advice and exercise plus true or non-penetrating acupuncture. Before randomisation, patients recorded their general outcome expectations, treatment-specific preferences and expectations. Clinical outcome was (a) change scores on the Western Ontario and McMaster Osteoarthritis Index (WOMAC) and (b) treatment response according to the OMERACT-OARSI criteria. Physiotherapists recorded their treatment expectations and preferences for each patient following an assessment prior to randomisation. We investigated the relationship between (a) patient, (b) therapist and (c) matched patient–therapist preferences and expectations on clinical outcomes using univariate and multivariate analyses. There was no significant relationship between patients’ treatment preferences and clinical outcomes at 6 or 12 months nor between patients’ expectations and pain (WOMAC) at 6 or 12 months. Using our secondary outcome (OMERART-OARSI), those who received the treatment for which they had high expectations of benefit were almost twice as likely to be classified as a treatment responder at 6 months (odds ratio (OR) 1.7 (95% Confidence Interval 1.06, 2.79)) and 12 months (OR) 1.9 (1.13, 3.13). Therapists’ preferences and expectations for individual patients did not add further explanation of outcomes. There was no evidence of a relationship between patients’ treatment preferences or expectations and pain reduction. We found weak evidence, from secondary outcomes, that patients’ expectations, both general and treatment-specific, are related to clinical outcome from exercise and acupuncture.