J Pharm Pharmacogn Res 3(suppl. 1): S28, 2015
Proceedings of the 4th International Symposium on Pharmacology of Natural Products FAPRONATURA 2015 September 21st-25th, 2015; Cuban Society of Pharmacology. Topes de Collantes, Sancti Spiritus, Cuba.
OC-10: THE IMPACT OF PLACEBO ON PAIN AND PHYSICAL ACTIVITY IN PATIENTS WITH OSTEOARTHRITIS
Winther K1, Marstrand K2, Campbell-Tofte J3, Hansen P1.
Introduction: Expectations and imagination can blunt reality. Therefore, evaluating pain is difficult because measurements are often dependent on patients’ subjective interpretations. How can we trust subjective data obtained from patients? Literature shows that placebo can result in positive responder rates of 60% in osteoarthritis patients. The aim of this study was to distinguish authentic from fake responders in randomized placebo-controlled clinical trials. Material and Methods: Patients (120) were included in a trial, in which half received 2.5 g rose-hip powder of Rosa canina subtype Lito daily, while the remaining were administered placebo. Pain and physical activity were estimated using WOMAC. In addition, the inflammatory marker – CRP was measured and a correlation test of change in symptom scores: pain and physical activity vs body weight was conducted for each group. Results: Pain and daily activity improved significantly (p<0.01 and p<0.01), respectively, irrespective of treatment. The positive response rate was close to 60% in each group. This indicate that nearly two out of three patients responded to placebo treatment. Placebo was therefore “proven” to be as effective as active treatment. However, CRP levels significantly declined with active treatment and no change was observed with placebo (p<0.042) comparing groups. Correlation analysis of weight vs pain scores (p<0.020), as well as weight vs physical function (p<0.004), revealed significant negative correlations with active treatment, indicating dose-dependency. The lighter patient had more impact on symptom scores than the heavier. With the placebo group, there was no correlation between weight and pain or weight and levels of physical activity. Conclusions: Our data indicate that even when active treatment and placebo yield matching outcomes, it is possible to distinguish between the two groups by considering biochemical measurements and correlation analysis of patients’ weight vs symptom scores.
Citation Format: Winther K, Marstrand K, Campbell-Tofte J, Hansen P (2015) The impact of placebo on pain and physical activity in patients with osteoarthritis. [Abstract]. In: Proceedings of the FAPRONATURA 2015; 2015 Sep 21-25; Topes de Collantes, Sancti Spiritus: CSF. J Pharm Pharmacogn Res 3(Suppl. 1): S28. Abstract nr OC-10.