Does it work? Why does it work? Reconciling difficult questions.

Area of Science:

• Speech-Language Pathology
• Evidence-Based Practice
• Research Methodology

Background:

• The hierarchy of medical evidence often prioritizes randomized controlled trials (RCTs), which are effective when a treatment has a strong theoretical basis.
• However, for treatments with less developed theoretical underpinnings, RCTs alone may not fully explain how they work, necessitating diverse research methods.

Purpose of the Study:

• To explore the types of evidence needed to confidently assess the benefits of treatments for individuals with communication difficulties.
• To demonstrate how synthesizing knowledge from various research methodologies can deepen understanding of a specific treatment, using the Lidcombe Program as a case example.

Main Methods:

• Review of frameworks for evaluating healthcare interventions.
• Analysis of research evidence for the Lidcombe Program of early stuttering intervention.
• Integration of evidence from RCTs, external research, and clinical/client experiences.

Main Results:

• Different types of evidence contribute uniquely to knowledge and practice in communication interventions.
• A practical example illustrates how combining systematic research, external studies, and practical experience enhances understanding of treatment approaches like the Lidcombe Program.
• Synthesis of diverse evidence informs both the efficacy ('Does it work?') and mechanistic ('How does it work?') aspects of treatments.

Conclusions:

• Addressing both 'Does it work?' and 'How does it work?' requires varied research methodologies.
• Relying on a single research method limits the information available to practitioners for justifying interventions and problem-solving.
• A multi-methodological approach, integrating various evidence types, is essential for comprehensive treatment evaluation and effective clinical application in communication disorders.