The Methodological Quality Scale (MQS) for intervention programs: validity evidence.

Area of Science:

• Program Evaluation
• Psychometrics
• Intervention Research

Background:

• Assessing the methodological quality (MQ) of intervention programs is crucial.
• Existing instruments often lack comprehensive metric quality studies.
• There is a need for a reliable and valid tool for MQ assessment.

Purpose of the Study:

• To introduce and validate the Methodological Quality Scale (MQS).
• To provide a simple, useful tool with adequate reliability, validity, and metric properties for assessing MQ.
• To address the gap in metric quality studies for MQ assessment instruments.

Main Methods:

• The MQS was independently applied by two coders to primary studies.
• Factor analyses were performed to determine MQ facets.
• Reliability, average discrimination, and validity facet scores were analyzed and interpreted using Shadish, Cook, and Campbell's model.

Main Results:

• Empirical validation of MQS across external, internal, and construct validity facets was achieved.
• The MQS demonstrated adequate metric properties and ease of application.
• MQ profiles can be generated for various intervention areas and methodologies.

Conclusions:

• The MQS is a practical and psychometrically sound instrument for evaluating intervention program quality.
• It is beneficial for meta-analysis researchers, evaluators, and intervention designers.
• The scale aids in understanding and improving the quality of intervention programs.