Research Summary

Defining Meaningful Change in Childhood Epilepsy Care

Miranda Manier, BA

Key Highlights:

  • This is the first study to estimate minimum clinically important difference (MCID) values for the QOLCE-55 and QOLCE-16.
  • Anchor-based MCID estimates were 10 points for the QOLCE-55 and 13 points for the QOLCE-16.
  • These estimates provide clinicians with benchmarks for determining meaningful improvements in health-related quality of life in children with epilepsy.
  • Results support prioritizing anchor-based methods when interpreting MCID.

In a first-of-its-kind analysis, researchers have established the minimum clinically important difference (MCID) for two widely used parent-reported measures of health-related quality of life (HRQOL) in children with epilepsy: the 55-item QOLCE-55 and the 16-item QOLCE-16. Using an anchor-based approach, the MCID was determined to be 10 points for the QOLCE-55 and 13 points for the QOLCE-16. Distribution-based estimates yielded slightly lower thresholds (6 and 7 points, respectively). These findings provide benchmarks for clinicians interpreting HRQOL changes in practice and research.

Children with epilepsy (CWE) are at significant risk for psychiatric, behavioral, and cognitive comorbidities, all of which can negatively affect HRQOL. Despite the common use of HRQOL tools like the QOLCE-55 and QOLCE-16, there has been no prior research establishing what constitutes a clinically meaningful change in score. Understanding the MCID for these instruments is important, as statistically significant differences may not always reflect changes that are important to patients or their families.

The study used data from 74 CWE aged 4 to 10 years enrolled in the Making Mindfulness Matter in Epilepsy (M3-E) trial, a randomized controlled trial evaluating a mindfulness-based intervention. MCID was estimated using both anchor-based and distribution-based methods. The anchor-based approach used the Patient Centered Global Ratings of Change (PCGRC) scale, while the distribution-based approach used half the standard deviation of the HRQOL change scores. Linear regression analysis determined the mean HRQOL score change associated with a PCGRC rating of 3 (somewhat better) as the anchor-based MCID.

Using the anchor-based approach, the estimated MCID was 9.8 points for the QOLCE-55 and 13.3 points for the QOLCE-16. Distribution-based estimates were 5.9 and 6.6 points, respectively. The anchor-based estimates were prioritized due to their greater relevance to patient-perceived improvement. The study emphasized that MCID interpretation may vary depending on the context of use; for instance, higher thresholds may be preferable in drug trials, while lower thresholds might be appropriate in exploratory interventions like education or mindfulness.

Limitations of the study include its small sample size and limited generalizability, as participants were restricted to children under age 11 and families with high educational attainment and two-parent households. The MCID values also apply only to improvements, not deterioration, in HRQOL.

“This is the first study to report MCID values for the QOLCE-55 and the QOLCE-16,” Leda et al. concluded. “Although using both distribution-based and anchor-based methods is recommended, some authors argue that anchor-based methods should be primarily used to estimate the MCID. Therefore, the MCID values obtained through anchor-based methods may be considered the primary estimates … Ultimately, the MCID values should be used with caution awaiting replication in studies with larger samples.”

 

Reference:
Leda M, Puka K, Bax K, Gagnier JJ, Tassiopoulos K, Speechley KN. Establishing the minimum clinically important difference of the Quality of Life in Childhood Epilepsy Questionnaire. Epilepsia. 2024;65(12):3536-3544. doi:10.1111/epi.18140