Investigating Hope and Expectations in Open-Label Placebos (I-HELP)

Hope and Expectations as Components of Open-Label Placebos: An Experimental Study Investigating Pain

Research has shown that placebo effects contribute substantially to clinical outcomes. Recent evidence suggests that placebos remain effective even if they are openly described as placebos (so-called Open-Label Placebos). In this study, the investigators examine hope and expectations as components of open-label placebos in an experimental study investigating pain..

Study Overview

• Status: Completed
• Conditions: Pain
• Intervention / Treatment: Other: DP; Other: Placebo cream; Other: Heat pain; Other: OLP Hope; Other: OLP Expectation

Detailed Description

A growing body of research has indicated that placebos contribute substantially to clinical outcomes. Yet, the implementation of deceptive placebos in clinical practice is incompatible with key principles of openness and patient autonomy. However, recent research suggests that placebos remain effective even if they openly described as placebos (so-called Open-Label Placebos (OLP)), hence questioning the necessity of deception in clinical trials. However, research identifying the specific mechanisms underlying OLP is lacking. Therefore, the current study aims to examine hope and expectations as components of OLP in pain.

For this purpose, experimentally induced heat pain is examined. First, all participants receive heat pain stimuli and evaluate them. Next, participants are randomly assigned to one of four groups: (1) a traditional deceptive placebo (DP) group, which is told that they receive an effective analgesic cream, (2) an OLP group inducing hope among the participants that the placebo cream could help them tolerating painful stimuli (OLP hope), (3) and OLP group raising the expectation that the placebo cream will help participants tolerating heat pain (OLP expectation), (4) a control group receiving no cream. Finally, participants receive and evaluate heat pain again.

• Study Type: Interventional
• Enrollment (Actual): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Germany
  • Hessen
    • Marburg, Hessen, Germany, 35037
      • Philipps-University of Marburg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• sufficient German language knowledge
• at least 18 years old

Exclusion Criteria:

• current mental disorder
• current medical disease
• studying psychology or medicine
• pregnancy or breastfeeding period
• intake of drugs
• severely visually impaired

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Deceptive Placebo (DP); After pretreatment heat pain assessment, participants are informed that they are about to receive an effective analgesic cream. In fact, they receive a placebo cream. Next, the posttreatment pain assessment is conducted.	Other: DP; Participants are informed that they are about to receive an effective analgesic cream. They are instructed to apply the cream using a cotton pad.; Other: Placebo cream; The participants receive an inert placebo cream (standard basic cream with oil of thyme produced by a local pharmacy).; Other: Heat pain; Participant receive heat pain stimuli using the suprathreshold method of the Thermo Sensory Analyser (TSA-II), a commonly used device to study pain sensation and analgesic effects.
EXPERIMENTAL: OLP with Hope (OLP Hope); After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect. Next, the posttreatment pain assessment is conducted.	Other: Placebo cream; The participants receive an inert placebo cream (standard basic cream with oil of thyme produced by a local pharmacy).; Other: Heat pain; Participant receive heat pain stimuli using the suprathreshold method of the Thermo Sensory Analyser (TSA-II), a commonly used device to study pain sensation and analgesic effects.; Other: OLP Hope; Participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. Therefore, participants are supposed to evaluate the subjective probability for a positive effect of the cream as rather low. However, using verbal instructions, the investigator aims to induce hope among the participants that the cream could have a positive effect for them because this placebo cream did have a positive among some former participants who were similar to the current participant. The emphasis of this similarity (regarding age and sex) aims to induce a feeling of connectedness to previous participants who reported positive effects of the placebo cream.
EXPERIMENTAL: OLP with Expectations (OLP Expectation); After pretreatment heat pain assessment, participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, using verbal instructions, the investigator aims to raise expectations among the participants that the cream will have a positive effect. Next, the posttreatment pain assessment is conducted.	Other: Placebo cream; The participants receive an inert placebo cream (standard basic cream with oil of thyme produced by a local pharmacy).; Other: Heat pain; Participant receive heat pain stimuli using the suprathreshold method of the Thermo Sensory Analyser (TSA-II), a commonly used device to study pain sensation and analgesic effects.; Other: OLP Expectation; Participants are informed that they are about to receive an placebo cream. They are told that the cream has no active pharmacological ingredient. However, participants are told that placebos have been shown to contribute substantially to clinical outcomes such as pain intensity/unpleasantness. This positive effect of placebos is reasoned by explaining learning mechanisms such as classical conditioning. We anticipated that after hearing this instruction, participants would consider it to be likely that the placebo has a positive effect for them.
EXPERIMENTAL: Control; After pretreatment heat pain assessment, this group does not receive an intervention targeting pain sensation prior to the posttreatment pain assessment.	Other: Heat pain; Participant receive heat pain stimuli using the suprathreshold method of the Thermo Sensory Analyser (TSA-II), a commonly used device to study pain sensation and analgesic effects.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pain intensity scale	Change in subjective pain intensity assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain intensity)	Baseline and 45 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pain unpleasantness scale	Change in subjective pain unpleasantness assessed using a visual analogue scale (ranging from 0 to 100, with higher values reflecting more pain unpleasantness)	Baseline and 45 minutes
Change in physiological heat pain threshold	Change in the individual heat pain threshold (the point when the stimulus changes from being warm to being painful)	Baseline and 45 minutes
Change in physiological heat pain tolerance	Change in the individual heat pain tolerance (the point when participants cannot stand the heat pain stimulus any longer)	Baseline and 45 minutes

Collaborators and Investigators

• Sponsor: Philipps University Marburg Medical Center
• Investigators: Principal Investigator: Tobias Kube, M. Sc., Philipps University Marburg Medical Center

Study record dates

Study Major Dates

• Study Start (ACTUAL): February 10, 2018
• Primary Completion (ACTUAL): June 30, 2018
• Study Completion (ACTUAL): August 21, 2018

Study Registration Dates

• First Submitted: March 7, 2018
• First Submitted That Met QC Criteria: April 24, 2018
• First Posted (ACTUAL): May 7, 2018

Study Record Updates

• Last Update Posted (ACTUAL): August 23, 2018
• Last Update Submitted That Met QC Criteria: August 22, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: 2017-58v

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No IPD will be shared

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No