Minimal important change for the aphasia quotient of the Chinese Western Aphasia Battery.

Background: There is limited research on the Minimal Important Change (MIC) of the Chinese Western Aphasia Battery (WAB). Since an MIC for Chinese WAB has yet to be established, the clinical implications of data using the Chinese WAB remain unclear.

Aim: This study was to establish the MIC of the Aphasia Quotient (AQ) of the Chinese WAB.

Design: The study is a prospective, longitudinal study.

Setting: The rehabilitation department of a Class A tertiary hospital.

Population: One hundred six patients with aphasia after stroke were included and analyzed in the study.

Methods: Patients were evaluated by a speech and language therapist using the Chinese version of WAB before and after the 2 week intervention. Patients and their primary therapist and caregiver provided a global rating of changes in patients' oral communication ability using the 7-point Likert Scale after the speech and language therapy. Three anchor-based methods were used to examine the MIC: the ROC-based method (MICROC), the predictive modeling method (MICpred), and the MICpred-based method adjusted for the proportion of improvement (MICadj).

Result: MICadj was the best parameter in this study. The participant, caregiver, and therapist anchor-based MICadj estimated in the present study was 6.98, 6.73, and 6.00, respectively.

Conclusions: Our data provide the first estimate of MIC value for the Chinese WAB-AQ. Future studies with larger sample sizes are needed to refine the estimated value.

Clinical Rehabilitation Impact: The current study has advanced the research on the properties of Chinese WAB.