What constitutes a clinically important change in Mayo Elbow Performance Index and range of movement after open elbow
Ziyang Sun1, Juehong Li1, Gang Luo1
1Department of Orthopedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
Aims:
This study aimed to determine the minimal detectable change (MDC), minimal clinically important difference (MCID), and substantial clinical benefit (SCB) under distribution- and anchor-based methods for the Mayo Elbow Performance Index (MEPI) and range of movement (ROM) after open elbow arthrolysis (OEA). We also assessed the proportion of patients who achieved MCID and SCB; and identified the factors associated with achieving MCID.
Methods:
A cohort of 265 patients treated by OEA were included. The MEPI and ROM were evaluated at baseline and at two-year follow-up. Distribution-based MDC was calculated with confidence intervals (CIs) reflecting 80% (MDC 80), 90% (MDC 90), and 95% (MDC 95) certainty, and MCID with changes from baseline to follow-up. Anchor-based MCID (anchored to somewhat satisfied) and SCB (very satisfied) were calculated using a five-level Likert satisfaction scale. Multivariate logistic regression of factors affecting MCID achievement was performed.
Results:
The MDC increased substantially based on selected CIs (MDC 80, MDC 90, and MDC 95), ranging from 5.0 to 7.6 points for the MEPI, and from 8.2° to 12.5° for ROM. The MCID of the MEPI were 8.3 points under distribution-based and 12.2 points under anchor-based methods; distribution- and anchor-based MCID of ROM were 14.1° and 25.0°. The SCB of the MEPI and ROM were 17.3 points and 43.4°, respectively. The proportion of the patients who attained anchor-based MCID for the MEPI and ROM were 74.0% and 94.7%, respectively; furthermore, 64.2% and 86.8% attained SCB. Non-dominant arm (p = 0.022), higher preoperative MEPI rating (p < 0.001), and postoperative visual analogue scale pain score (p < 0.001) were independent predictors of not achieving MCID for the MEPI, while atraumatic causes (p = 0.040) and higher preoperative ROM (p = 0.005) were independent risk factors for ROM.
Conclusion:
In patients undergoing OEA, the MCID for the increased MEPI is 12.2 points and 25° increased ROM. The SCB is 17.3 points and 43.3°, respectively. Future studies using the MEPI and ROM to assess OEA outcomes should report not only statistical significance but also clinical importance. Cite this article: Bone Joint J 2021;103-B(2):366-372.
Insights
This study determined the minimal clinically important difference (MCID) for elbow performance and range of motion after open elbow arthrolysis. Key findings establish benchmarks for meaningful patient recovery following the procedure.
Area of Science:
- Orthopedic Surgery
- Rehabilitation Medicine
- Clinical Outcomes Measurement
Background:
- Open elbow arthrolysis (OEA) is a surgical procedure to improve elbow function.
- Assessing the meaningful improvement in patient outcomes after OEA is crucial for clinical practice and research.
- Establishing minimal detectable change (MDC), minimal clinically important difference (MCID), and substantial clinical benefit (SCB) provides valuable benchmarks.
Purpose of the Study:
- To determine the MCID and SCB for the Mayo Elbow Performance Index (MEPI) and range of motion (ROM) after OEA using distribution- and anchor-based methods.
- To assess the proportion of patients achieving MCID and SCB.
- To identify factors associated with achieving MCID.
Main Methods:
- A cohort of 265 patients undergoing OEA were evaluated for MEPI and ROM at baseline and two-year follow-up.
- Distribution-based MDC and anchor-based MCID/SCB were calculated using established methodologies and a Likert satisfaction scale.
- Multivariate logistic regression analyzed factors influencing MCID achievement.
Main Results:
- Anchor-based MCID for MEPI was 12.2 points and for ROM was 25.0°. SCB was 17.3 points for MEPI and 43.4° for ROM.
- 74.0% of patients achieved MCID for MEPI, and 94.7% for ROM. SCB was achieved by 64.2% (MEPI) and 86.8% (ROM).
- Factors like non-dominant arm, preoperative MEPI, and postoperative pain predicted MEPI MCID achievement; atraumatic causes and preoperative ROM predicted ROM MCID achievement.
Conclusions:
- The MCID after OEA is 12.2 points for MEPI and 25° for ROM, with SCB at 17.3 points and 43.3°, respectively.
- A significant proportion of patients achieve clinically important improvements after OEA.
- Future studies should report both statistical significance and clinical importance (MCID/SCB) for OEA outcomes.
