Inventory-Description

The Vancouver Obsessional Compulsive Inventory (VOCI-55) is a psychometric tool designed to assess the severity and range of symptoms of obsessive-compulsive disorder (OCD). The questionnaire consists of 55 items that cover a variety of symptoms and behaviors associated with OCD.

The VOCI-55 aims to evaluate the main dimensions of obsessive-compulsive disorder, which include:

Contamination: Fear of contamination and excessive cleaning behaviors.

Checking: Obsession with checking, such as repeatedly verifying things (e.g., whether doors are locked).

Obsessions: Intense, repetitive thoughts related to danger or potential harm.

Symmetry/Ordering: Need for symmetry and arranging objects in a specific way.

Hoarding: Difficulty discarding items and excessive collection of things.

Neutralizing (Unwanted Thoughts): Obsessions with moral issues or inappropriate thoughts.

Each item is rated on a Likert scale, where participants assess the frequency and intensity of their thoughts or behaviors.

Data Analysis and Usage

The data collected from the VOCI-55 can be used to understand the spectrum of OCD symptoms in an individual. Analyses applied to VOCI-55 data include:

Reliability analysis, such as calculating Cronbach’s alpha, to measure the internal consistency of the questions within each subscale.

Factor analysis to confirm the structure of the dimensions measured by the questionnaire.

Correlation analysis to examine the relationship between OCD symptoms and other psychological factors, such as anxiety or depression.

Data from the VOCI-55 can be used in clinical studies to assess the severity of OCD, monitor progress during treatment, and tailor therapeutic approaches to individual needs.

Purpose

The main goal of the Vancouver Obsessional Compulsive Inventory (VOCI-55) is to provide a detailed assessment of OCD symptoms. This helps clinical psychologists and researchers to:

Identify specific patterns of obsessions and compulsions in an individual.

Determine the severity of OCD.

Design and monitor the effectiveness of interventions, whether they are pharmaceutical or psychotherapeutic.

Calibration

The calibration of the VOCI-55 involves the following stages:

Reliability analysis to estimate the internal consistency of the different subscales, ensuring that the items consistently measure the same dimension of OCD symptoms.

Factor analysis to confirm the structure of the six dimensions of the questionnaire.

Cross-validation in different populations to ensure that the tool is valid and reliable for various groups of individuals.

Bibliography

Thordarson, D. S., Radomsky, A. S., Rachman, S., Shafran, R., Sawchuk, C. N., & Hakstian, A. R. (2004). The Vancouver Obsessional Compulsive Inventory (VOCI). Behaviour Research and Therapy, 42(11), 1289-1314.

Radomsky, A. S., Thordarson, D. S., Rachman, S. (2006). The Vancouver Obsessional Compulsive Inventory (VOCI): Further validation in a clinical sample. Behaviour Research and Therapy, 44(1), 123-136.

Rachman, S. (1997). A cognitive theory of obsessions. Behaviour Research and Therapy, 35(9), 793-802.