How Effective Is the Yale-Brown Obsessive Compulsive Scale for Binge Eating in Assessing Binge Eating Disorder?

What you need to know

The Yale-Brown Obsessive Compulsive Scale modified for Binge Eating (Y-BOCS-BE) is a valuable tool for assessing binge eating disorder symptoms.
The Y-BOCS-BE measures three aspects of binge eating: obsessive/compulsive thoughts and behaviors, ability to restrain from binge eating, and ability to control binge eating.
The reliability and validity of the Y-BOCS-BE improve over time as patients gain insight into their binge eating disorder through treatment and self-monitoring.

Understanding binge eating disorder and its assessment

Binge eating disorder (BED) is characterized by recurrent episodes of eating large amounts of food in a short period of time, accompanied by a sense of lack of control. Unlike bulimia nervosa, people with BED do not regularly engage in compensatory behaviors like purging or excessive exercise after binge eating. BED can significantly impact quality of life and is associated with obesity and other health problems.

Accurately assessing BED symptoms is crucial for diagnosis, treatment planning, and monitoring progress. The Yale-Brown Obsessive Compulsive Scale modified for Binge Eating (Y-BOCS-BE) is a tool designed to measure the severity of binge eating symptoms. It was adapted from a scale originally used to assess obsessive-compulsive disorder.

This study aimed to thoroughly evaluate the psychometric properties of the Y-BOCS-BE - in other words, to determine how well it measures what it’s intended to measure in adults with BED. The researchers analyzed data from three large clinical trials testing a medication called lisdexamfetamine for treating BED.

How the Y-BOCS-BE works

The Y-BOCS-BE contains 10 questions that assess different aspects of binge eating thoughts and behaviors. For each item, clinicians rate the severity on a scale from 0 (no symptoms) to 4 (extreme symptoms). The total score ranges from 0 to 40, with higher scores indicating more severe binge eating symptoms.

The questions cover areas like:

How much time is occupied by thoughts about binge eating
How much binge eating interferes with work or social activities
Level of distress caused by binge eating thoughts and behaviors
Ability to resist binge eating urges
Degree of control over binge eating

Key findings on the structure and reliability of the Y-BOCS-BE

Measuring distinct aspects of binge eating

The researchers found that the Y-BOCS-BE measures three main aspects of binge eating:

Obsessive/compulsive: This includes time spent on binge eating thoughts and behaviors, how much they interfere with life, and the distress they cause.
Restraint: The ability to resist thoughts and urges related to binge eating.
Control: The degree of control over binge eating thoughts and behaviors.

However, they determined that looking at the total score as an overall measure of binge eating severity was most appropriate for clinical use.

Reliability improves over time

The study found that the reliability of the Y-BOCS-BE - how consistently it measures binge eating symptoms - was initially low at the start of treatment but improved substantially over time.

For example, when looking at how well individual items on the scale related to the total score:

At the start of treatment, correlations ranged from 0.20 to 0.56
By week 12 of treatment, correlations improved to 0.74 to 0.85

The overall internal consistency of the scale also improved from 0.77 at baseline to 0.96 at week 12.

This suggests that as patients undergo treatment and become more aware of their binge eating patterns, they may be better able to accurately report their symptoms. The experience of regularly evaluating their binge eating through the Y-BOCS-BE likely contributes to this improved insight as well.

Test-retest reliability

The researchers also looked at test-retest reliability - how consistent scores are when the test is given multiple times to the same person. They found:

Low reliability between baseline and week 4 (correlations of 0.34 to 0.59)
Much better reliability between week 4 and week 12 (correlations of 0.77 to 0.90)

Again, this indicates that the Y-BOCS-BE becomes a more reliable measure over time as patients gain insight into their binge eating patterns.

Validity of the Y-BOCS-BE

Validity refers to how well a scale measures what it’s intended to measure. The researchers examined this by comparing Y-BOCS-BE scores to other measures of eating behaviors and binge eating symptoms.

They found that correlations between the Y-BOCS-BE and other measures were initially weak at the start of treatment. However, by week 12, the Y-BOCS-BE showed strong correlations with most other measures, indicating good validity.

The researchers suggest this pattern may be due to poor insight into binge eating symptoms at the beginning of treatment. People with BED often have difficulty recognizing and describing their emotions and bodily sensations related to binge eating. As they undergo treatment and regularly evaluate their symptoms, their ability to accurately report binge eating behaviors likely improves.

Determining meaningful change in Y-BOCS-BE scores

An important question when using any assessment tool is: How much does the score need to change to reflect a meaningful improvement in symptoms?

The researchers used several methods to estimate what would constitute a clinically meaningful improvement in Y-BOCS-BE scores. They determined that a reduction of 12 to 17 points in the total score (out of 40) likely represents a meaningful improvement in binge eating symptoms.

This is valuable information for both clinicians and researchers to interpret changes in Y-BOCS-BE scores over the course of treatment.

Effectiveness of lisdexamfetamine in improving Y-BOCS-BE scores

While not the main focus of this study, the researchers also looked at how effective the medication lisdexamfetamine was in improving Y-BOCS-BE scores compared to placebo.

They found that patients taking lisdexamfetamine showed significantly greater improvements in Y-BOCS-BE scores compared to those taking placebo. This was consistent across all three clinical trials analyzed.

These results provide further support for the Y-BOCS-BE as a useful tool for assessing treatment effects in binge eating disorder.

Conclusions

The Y-BOCS-BE is a valuable instrument for assessing binge eating disorder symptoms, measuring obsessive-compulsive aspects, restraint, and control related to binge eating.
The reliability and validity of the Y-BOCS-BE improve over time as patients gain insight into their binge eating patterns through treatment and self-monitoring.
A reduction of 12-17 points in the Y-BOCS-BE total score likely represents a clinically meaningful improvement in binge eating symptoms.

This study provides important information on the strengths and limitations of the Y-BOCS-BE for assessing binge eating disorder. The findings can help clinicians and researchers better interpret Y-BOCS-BE scores and use the scale effectively in treatment and research settings. Regular self-monitoring of binge eating symptoms may be valuable not only for assessing progress, but also for helping patients gain insight into their eating patterns.