Overview
This lecture reviews critical appraisal of interventional studies using the PEDro scale, with step-by-step analysis of two research articles, to help physical therapists assess study quality for evidence-based practice.
Introduction to the PEDro Scale
- The PEDro scale is used to assess the quality of interventional studies, focusing on objective measures in methods and results sections.
- The scale contains 11 items, but only items 2–11 are scored; item 1 relates to generalizability and is not included.
- Items 2–9 address internal validity; items 10–11 address statistical conclusion validity.
- Detailed notes for each criterion are available on the PEDro scale form, aiding users in administration.
Importance of Critical Appraisal
- Critical appraisal helps identify potential bias, often present as "spin" in research articles.
- Only about half of physical therapists can critically appraise articles; lack of this skill is a barrier to evidence-based practice.
- High PEDro scores and significant results do not automatically mean an intervention should be adopted.
PEDro Scale Example: Mirror Therapy for Unilateral Neglect
- The study met criteria for eligibility specified, random assignment, concealed allocation, similar groups at baseline, and assessor blinding.
- Did not meet criteria for participant or therapist blinding, nor intention-to-treat analysis.
- Key outcomes were measured in >85% of participants; between-group comparisons and point/variability measures were provided.
- Final PEDro score: 7/10 (high quality).
PEDro Scale Example: Pilates Exercise for Health Workers
- Eligibility criteria were specified; groups were similar at baseline; assessor blinding achieved for one key outcome.
- Did not meet random assignment, concealed allocation, or blinding of participants/therapists, or intention-to-treat analysis.
- Key outcomes measured in >85% of participants; point/variability measures provided but no between-group statistical comparison.
- Final PEDro score: 4/10 (fair quality).
Study Validity and Evidence-Based Practice
- PEDro scores categorize studies as poor (≤3), fair (4–5), or high quality (≥6).
- Clinical significance, effect size, and context are important, not only PEDro scores.
- Most needed information is in the methods and results sections, making critical appraisal more manageable.
Key Terms & Definitions
- PEDro scale — A checklist to assess methodological quality of physical therapy trials.
- Random assignment — Allocating participants to groups by chance to reduce bias.
- Concealed allocation — Keeping upcoming group assignments hidden during enrollment to prevent selection bias.
- Blinding — Keeping participants, therapists, or assessors unaware of group assignments to minimize bias.
- Intention-to-treat analysis — Including all randomized participants in the analysis, regardless of protocol adherence.
Action Items / Next Steps
- Practice applying the PEDro scale to new interventional articles.
- Focus on reading methods and results sections for objective appraisal.
- Consider joining the APTA Kansas research committee if interested in research or publication.
- Complete the Qualtrics survey for feedback on the session.