Rasch-modeling the Portuguese SOCRATES in a clinical sample

Area of Science:

• Psychology
• Addiction Research
• Psychometrics

Background:

• Assessing patient motivation is crucial for effective substance abuse treatment and rehabilitation.
• The Stages of Change Readiness and Treatment Eagerness Scale (SOCRATES) is a key tool for measuring treatment motivation.
• Validating psychometric properties in diverse populations enhances scale utility.

Purpose of the Study:

• To evaluate the psychometric properties of the SOCRATES in a Portuguese substance-abusing population.
• To optimize the scale's response categories for improved measurement accuracy.
• To inform the development of more effective motivation-for-treatment scales.

Main Methods:

• Employed the Rasch Rating Scale Model for conjoint measurement of items and persons.
• Analyzed data from 166 individuals undergoing treatment for substance addiction.
• Re-analyzed the SOCRATES response categories to determine optimal functioning.

Main Results:

• The original five-category response system of the SOCRATES did not function optimally.
• A revised three-category response system significantly improved model fit and estimation accuracy.
• The study identified areas for improvement in item format and content.

Conclusions:

• A three-category response system is more appropriate for the SOCRATES in this population.
• Optimizing the SOCRATES enhances the accurate measurement of treatment motivation.
• Findings provide a basis for developing improved scales to assess motivation in addiction treatment.