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Does Placebo Information Affect the Trial Outcomes and Participant Blinding?

Not Applicable
Completed
Conditions
Muscle Soreness
Registration Number
NCT04182295
Lead Sponsor
Kyunghee University
Brief Summary

This is a randomised sham-controlled trial involving healthy volunteers to determine the effect of information on placebo, i.e., sham acupuncture, given in the informed consent, on the trial outcomes and blinding status of participants in a trial.

Detailed Description

A total of 89 healthy volunteers will be recruited and randomly allocated to one of the 4 groups at an identical ratio. Four groups differ in acupuncture and placebo information. It is summarized as follows:

1. to receive real acupuncture and to read fully disclosed sham acupuncture information (e.g., fake acupuncture) written in the informed consent

2. to receive real acupuncture and to read partially disclosed sham acupuncture information (e.g., different kind of acupuncture) written in the informed consent

3. to receive sham acupuncture (Park Sham Needle) and to read fully disclosed sham acupuncture information written in the informed consent

4. to receive sham acupuncture to read partially disclosed sham acupuncture information (e.g., different kind of acupuncture) written in the informed consent.

They will read informed consent with differently described placebo information following their allocation. After participants repeatedly lift a dumbbell with their non-dominant arm to induce delayed onset muscle soreness (DOMS) in their biceps brachii, they are given allocated acupuncture treatment once a day for three consecutive days including the very first visit to compare outcomes (i.e., relief of DOMS measured with pressure pain threshold and visual analogue scale) and blinding property (the participants will be asked 'which type of acupuncture do you think you have received?' and choose 1 answer out of real, sham, or don't know options).

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
89
Inclusion Criteria
  • age over 18
  • not participating in other studies at the time of study participation
  • voluntary participation
Exclusion Criteria
  • resistance training for more than 6 months
  • experience of fracture of any of four limbs
  • pregnancy or breast-feeding at the time of study participation
  • analgesics within 24 hours before participation
  • any other diseases or conditions that might prevent the participant from receiving acupuncture

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
the change in muscle discomfort from baseline, i.e., immediately after being induced DOMS, measured by visual analogue scale (VAS)day 0; day 1; day 2

Muscle discomfort of DOMS induced arm is evaluated with VAS ranging from 0 to 10 cm (with 0 indicating no discomfort and 10 experiencing the worst imaginable muscle discomfort.)

Blinding propertyday 2

Blinding property is evaluated: participants will be asked 'which type of acupuncture do you think you have received?' and choose 1 answer out of experimental group, control group, and do not know. It is calculated following the way of Bang's Blind Index; -1 indicates opposite guessing; 0 indicates random guessing; 1 indicates correct guessing.

the change in Pressure Pain Threshold (PPT) from baseline, i.e., before being induced DOMSday 0; day 1; day 2

Pressure Pain Threshold (PPT) will be evaluated on the 5 points of upper non-dominant arm. Five points are selected from 6 equidistance from origin to insertion of biceps brachii with an exception of the first and last point, perpendicular to the belly of the biceps brachii. Pressure was applied to each of these points with increasing force at a rate of approximately 10 N/cm2\*sec until the participant reported a painful sensation, and the force value was recorded (N/cm2). An upper limit of PPt was set 50 N/cm2 to avoid bruising.

Secondary Outcome Measures
NameTimeMethod
Acupuncture sensation measured by De-qi questionnaireday 0; day 1; day 2

De-qi questionnaire (Kim et al.) is used to evaluate acupuncture sensation measured in VAS ranging from 0 to 10 cm (with 0 indicating no feeling of respective 18 items included in the questionnaire and 10 experiencing the worst imaginable feeling of respective 18 items included in the questionnaire.)

Trial Locations

Locations (1)

Acupuncture & Meridian Science Research Centre

🇰🇷

Seoul, Korea, Republic of

Acupuncture & Meridian Science Research Centre
🇰🇷Seoul, Korea, Republic of

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