Measurement properties of core outcomes in patients with tennis elbow.
The study found that while the PRTEE and grip strength measures are reliable, there are significant concerns regarding content validity and the interpretation of Minimal Important Change.
Where it sits
this study against the rest of the selank corpusSummary and findings
This study evaluated the measurement properties of the Patient-Rated Tennis Elbow Evaluation (PRTEE), grip strength, and pain metrics in 100 participants with tennis elbow. The study assessed reliability, internal consistency, validity, responsiveness, and Minimal Important Change (MIC). The findings indicated acceptable reliability but questionable content validity for some measures.
Abstract
<h4>Background</h4>The Patient-Rated Tennis Elbow Evaluation (PRTEE), pain on gripping, pain-free, and maximum grip strength are widely used outcomes for tennis elbow. This study tested the measurement properties with a prospective test-retest study design.<h4>Methods</h4>100 participants with tennis elbow were included. The reliability, internal consistency, validity, responsiveness, and the Minimal Important Change (MIC) were evaluated.<h4>Results</h4>The reliability of all measures was acceptable. 8/15 PRTEE items were below the criteria for content validity. For PRTEE total score (0-100), the smallest detectable change 95% (SDC<sub>95%</sub>) was 17 points, and for the pain and function subscales (0-50) 8 and 12. For pain on gripping (0-10), the SDC<sub>95%</sub> was 4, and 6.4 kg for pain-free grip strength and 8.4 kg for maximum grip strength. The MIC for PRTEE total score was 9 points, 11 for pain and 4 for function. The MIC was 3.5 for pain on gripping, and 6.5 kg and 1 kg for pain-free and maximum grip strength. Construct validity was confirmed for PRTEE, pain-free grip strength, and pain on gripping. PRTEE pain and pain-free grip strength were responsive.<h4>Conclusion</h4>All measurements were reliable. PRTEE had questionable content validity. The interpretation of MIC is challenging due to large measurement errors.
Background
This paper addresses the measurement properties of core outcomes in patients with tennis elbow, a common musculoskeletal condition. Previous studies have utilized various metrics to assess outcomes, but there is limited understanding of their reliability and validity. This study is significant as it aims to clarify the measurement properties of widely used outcomes in this population.
Methods
The study employed a prospective test-retest design with 100 participants diagnosed with tennis elbow. It evaluated reliability, internal consistency, validity, responsiveness, and Minimal Important Change (MIC) across several outcome measures. Specific metrics included the Patient-Rated Tennis Elbow Evaluation (PRTEE), grip strength, and pain assessments.
Results
The reliability of all measures was found to be acceptable. The smallest detectable change (SDC95%) for the PRTEE total score was 17 points. For the pain and function subscales, the SDC95% was 8 and 12 points, respectively. The MIC for the PRTEE total score was determined to be 9 points, with additional MIC values reported for pain and grip strength metrics.
Interpretation
While the study confirms acceptable reliability for the evaluated measures, the questionable content validity of 8 out of 15 PRTEE items raises concerns about their overall utility. The effect sizes reported, while statistically significant, may not translate to clinically meaningful changes due to the large measurement errors associated with the MIC. The findings suggest that practitioners should exercise caution when interpreting these scores in clinical practice.
Key findings
- Smallest detectable change (SDC95%) for PRTEE total score was 17 points.
- SDC95% for pain and function subscales were 8 and 12 points, respectively.
- SDC95% for pain on gripping was 4.
- SDC95% for pain-free grip strength was 6.4 kg.
- SDC95% for maximum grip strength was 8.4 kg.
- MIC for PRTEE total score was 9 points, with 11 for pain and 4 for function.
Limitations
- Questionable content validity for 8 out of 15 PRTEE items.
- Challenges in interpreting MIC due to large measurement errors.