The design and interpretation of randomized trials is intimately connected to the use of "placebo". The nature and magnitude of placebo effects, however, is very poorly understood. This study will assess and compare placebo effects and physician interaction effects within a community-acquired common cold model. The goal of this study is to assess two kinds of placebo affects and how physician interaction effects; 1. The effect of receiving blinded placebo, compared to no treatment; and 2. The effect of receiving open-label active Echinacea treatment compared to blinded active treatment.
As per Brief Summary
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
719
Echinacea phytochemical profile Each tablet is comprised of the equivalent of 1275 mg of echinacea root, as follows: A) Echinacea purpurea - 675 mg root yields 112.5 mg dried extract, standardized to contain 2.1mg alkamides. B) Echinacea angustifolia - 600 mg root yields 150 mg dried extract, standardized to contain 2.0 mg alkamides. Each batch of tablets is analyzed by Reversed Phase - High Peformance Liquid Chromatography to determine the levels of alkamides and caffeic derivatives present. Caffeic acid derivative levels are typically as follows: caftaric acid = 0.5 to 2.0 mg/tablet; cichoric acid = 3.4 to 8.5 mg/tablet; chlorogenic acid = \< 0.5 mg/tablet; dicaffeoyl quinic acids (including cynarin) = 0.7 to 2.0 mg/tablet; echinacoside = 1.0 to 1.7 mg/tablet
Blinded placebo - Coated tablet
University of Wisconsin-Madison Department of Family Medicine
Madison, Wisconsin, United States
Duration and severity of illness, as assessed by the Wisconsin Upper Respiratory Symptom Survey (WURSS-21)
Time frame: twice daily during illness
SF-8 general health-related quality of life
Time frame: daily during illness
perceived stress PSS-4
Time frame: daily during illness
optimism LOT
Time frame: two days after enrollment
patient satisfaction CARE
Time frame: after doctor patient interaction
feeling thermometer - EuroQol VAS
Time frame: daily during illness
IL-8 (inflammatory cytokine)from nasal wash
Time frame: 2 days after enrollment
neutrophil count from nasal wash
Time frame: two days after enrollment
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