Can Training Increase Reporting Accuracy and Study Power in Human Pain Trials

Study Overview
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Brief Summary
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In previous studies, results of both the Focused Analgesia Selection Test (FAST) procedure, a method to assess pain-reporting accuracy, and the Evoked Pain Training (EPT) procedure, aimed to improve pain-reporting accuracy, correlated with the placebo response. The objectives of the current project were to determine if EPT (1) increases pain reporting accuracy and (2) affect the placebo response in experimental pain study.

Detailed Description
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Analgesic trials suffer from low assay-sensitivity, and experts in the field are concerned that many previous negative analgesic trails might be regarded as failed trails. Major contributor to this concern is the large placebo response observed in analgesic clinical trials. Recent findings from the investigators group suggest that improving pain reporting accuracy could increase analgesic trials assay sensitivity by reducing the placebo response. In previous studies, the investigators developed the Focused Analgesia Selection Test (FAST), a method to assess pain reporting accuracy. Later on, the investigators developed the Evoked Pain Training (EPT), aimed to improve pain reporting accuracy. Both these methods constitute the core of this project. The objectives of the current project are to determine if subject training increases (1) pain reporting accuracy and (2) the power of an analgesic trial. Summary of main methods This project objectives will be achieved by preforming a two-stage study. First, all subjects undergo baseline assessments, including assessment of pain reporting accuracy (the FAST procedure) (visit #1). Then, subjects enter the first study stage (training stage), in which half of study subjects (n=50) undergo training to improve pain reporting accuracy. The training comprise of three in-clinic visits (visits #2, 3, 4) in which subjects receive feedback on accuracy of pain reports in response to noxious stimuli of various intensities (the EPT procedure). The EPT is based on repeated application of the FAST procedure, while providing feedback to subjects in between applications. The other half of subjects (n=50) undergo a shame-training. After completion of the training phase, all subjects enter an experimental cross-over study design (second study phase) comprised of two in-clinic visits (visits 5 and 6). In each of these two visits, subjects undergo a battery of experimental pain tests (pre-treatment assessment), take one of two pills (either Ibuprofen 400 mg or identical sugar pill) in a random order, wait approximately 1 hour, and then undergo the same pain tests again (post-treatment assessment).

Official Title
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Can Training Increase Reporting Accuracy and Study Power in Human Pain Trials

Conditions
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Healthy, Placebo Response

Intervention / Treatment
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* Drug: Ibuprofen 400 mg
* Drug: Placebo oral tablet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Absence of neurological, psychiatric, or chronic pain disorders. Have used at list once Ibuprofen, and not sensitive to NSAIDs. Ability to give informed consent, communicate, and understand the purpose and instructions of this study. Exclusion Criteria: Presence of diagnosed psychiatric disorders, cognitive and /or neurological deficits. Use of analgesic, anti-depressant or anti-enxiayoltic medications on a regular basis (except for oral contraceptives). Pregnancy. Never used NSAIDs.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Evoked pain training<br> | Drug: Ibuprofen 400 mg<br>* Each subject will receive Ibuprofen once, in between two psycho-physical assessments. Between the drug intake and the second assessment the subject will have to wait for 40 minutes.<br>Drug: Placebo oral tablet<br>* Each subject will receive Placebo (sugar pill) once, in between two psycho-physical assessments. Between the placebo pill intake and the second assessment the subject will have to wait for 40 minutes.<br>|
| Experimental: Control<br> | Drug: Ibuprofen 400 mg<br>* Each subject will receive Ibuprofen once, in between two psycho-physical assessments. Between the drug intake and the second assessment the subject will have to wait for 40 minutes.<br>Drug: Placebo oral tablet<br>* Each subject will receive Placebo (sugar pill) once, in between two psycho-physical assessments. Between the placebo pill intake and the second assessment the subject will have to wait for 40 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain reporting accuracy | Subjects will be asked to report their pain on numerical pain scale (NPS) ranging from 0, denoting no pain, to 10, denoting the worst pain imaginable. | Fast procedure itself (49 heat stimuli, from 7 designated heat temperatures, given in a random block-order design) lasting approximately 20 minutes. | 
| Change in experimental pain perception due to drug/placebo pill intake | Subjects will be asked to report their pain on numerical pain scale (NPS) ranging from 0, denoting no pain, to 10, denoting the worst pain imaginable. The placebo effect (Δ) will be calculated as the difference between the mean NPS. | Mechanical and thermal stimuli before the drug/placebo (Pre-drug/placebo) until receiving the same stimuli 40 minutes after taking the drug/placebo pill (Post-drug/placebo). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evoked pain training | Subjects will be asked to report their pain on numerical pain scale (NPS) ranging from 0, denoting no pain, to 10, denoting the worst pain imaginable. | Fast procedure itself (49 heat stimuli, from 7 designated heat temperatures, given in a random block-order design) lasting approximately 20 minutes. There are 3 training visits, each training consists of 2 FAST procedure and last approximately 1 hour. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Focus analgesia selection test (FAST), Experimental pain variability, Placebo effect, Evoked pain training (EPT)