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Learning to tolerate disgust: Behavioral strategies for reducing disgust in obsessive-compulsive symptoms
Last registered on June 24, 2020

Pre-Trial

Trial Information
General Information
Title
Learning to tolerate disgust: Behavioral strategies for reducing disgust in obsessive-compulsive symptoms
RCT ID
AEARCTR-0006032
Initial registration date
June 20, 2020
Last updated
June 24, 2020 8:05 AM EDT
Location(s)
Region
Primary Investigator
Affiliation
University of Bucharest
Other Primary Investigator(s)
Additional Trial Information
Status
Completed
Start date
2018-11-28
End date
2020-01-05
Secondary IDs
Abstract
The efficacy of exposure techniques for disgust has been poorly investigated so far. As it turns out, there are some promising, yet still unclear indications of the efficacy of exposure on disgust responses. Thus, the objective of this paper was to investigate the effects of behavioral interventions, compared to the control condition, especially regarding the level of disgust on people with obsessive-compulsive symptoms at post-intervention and follow-up. The efficacy of the two interventions was investigated within a randomized controlled trial. Participants were selected for scoring above the cut-off on a measure of OC symptoms. Thus, three groups were formed, more precisely a control group and two experimental groups (for counterconditioning and US-revaluation interventions). Those allocated in the experimental conditions participated in one intervention session. As a result, the current study has clinical implications, especially in terms of cognitive and behavioral interventions that can be used to decrease disgust in pathological cases.
External Link(s)
Registration Citation
Citation
Pascal, Simona Alexandra. 2020. "Learning to tolerate disgust: Behavioral strategies for reducing disgust in obsessive-compulsive symptoms." AEA RCT Registry. June 24. https://doi.org/10.1257/rct.6032-1.1.
Experimental Details
Interventions
Intervention(s)
Intervention Start Date
2018-12-06
Intervention End Date
2019-11-29
Primary Outcomes
Primary Outcomes (end points)
disgust, obsessive-compulsive symptoms
Primary Outcomes (explanation)
Disgust. This variable was measured with The Disgust Scale-Revised (DS-R; Olatunji et al., 2007) in various situations. DS-R includes 25 items; the first 13 items were rated on a dichotomous scale from false (0) to true (1) and the next 12 items were rated on a three-point Likert-type scale ranging from not disgusting (0) to very disgusting (1). An example of an item is “It would bother me tremendously to touch a dead body”. A total disgust score can be calculated by summing responses to the 25 items (0 – 25).
Obsessive-compulsive symptoms. This variable was measured with The Obsessive-Compulsive Inventory-Revised (OCI-R; Foa et al., 2002). This tool measures specific OC symptoms through 18 questions, with a sample item such as “I wash my hands more often and longer than necessary”. Items were rated on a Likert scale ranging from not at all (0) to extremely (4).
Secondary Outcomes
Secondary Outcomes (end points)
fear, cognitive errors
Secondary Outcomes (explanation)
Fear. This variable was measured with Fear Questionnaire (FQ; Marks & Mathews, 1979) through 24 items. An example item is “Walking alone in busy streets”. Participants rated the items on a nine-point Likert-type scale ranging from would not avoid it (0) to always avoid it (8).
Cognitive errors. This variable was measured with 5 scenarios adapted after The General Cognitive Error Questionnaire (CEQ; Possel, 2009), custom to OC symptoms. It measures how a person misconstrues the significance of events in a negative manner, in the case of disgust. Items were rated on a Likert scale ranging from almost exactly as I think (0) to almost exactly as I did not think (4).
Experimental Design
Experimental Design
To test the efficacy of intervention against the control condition, a 3 (groups: COUNTER versus USREV vs control) x 3 (time: pre vs. post vs. follow-up) mixed design with repeated measures analysis of variance was employed.
Experimental Design Details
To test the efficacy of intervention against the control condition, a 3 (groups: COUNTER versus USREV vs control) x 3 (time: pre vs. post vs. follow-up) mixed design with repeated measures analysis of variance was employed. The Bonferroni correction was used to adjust for multiple comparisons. In order to test the moderation model, the PROCESS macro in SPSS (Hayes, 2017) was used, with experimental groups as the independent variable, reduction in disgust as the dependent variable, and perception of OC stimuli in post-intervention as moderating variable (Figure 3). Thus, we controlled the initial measures of perception of the stimuli as disgusting by adding it as a covariate.
Randomization Method
Randomization done using https://www.random.org/
Randomization Unit
One randomization in three groups (control, counterconditioning, US-revaluation).
Was the treatment clustered?
No
Experiment Characteristics
Sample size: planned number of clusters
3 groups
Sample size: planned number of observations
114 participants
Sample size (or number of clusters) by treatment arms
38 participants control, 39 participants counterconditioning, 37 participants US-revaluation
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
IRB
INSTITUTIONAL REVIEW BOARDS (IRBs)
IRB Name
IRB Approval Date
IRB Approval Number
Post-Trial
Post Trial Information
Study Withdrawal
Intervention
Is the intervention completed?
Yes
Intervention Completion Date
January 05, 2020, 12:00 AM +00:00
Is data collection complete?
Yes
Data Collection Completion Date
January 05, 2020, 12:00 AM +00:00
Final Sample Size: Number of Clusters (Unit of Randomization)
Was attrition correlated with treatment status?
Final Sample Size: Total Number of Observations
114 participants
Final Sample Size (or Number of Clusters) by Treatment Arms
Data Publication
Data Publication
Is public data available?
No
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)
REPORTS & OTHER MATERIALS