Reliability and Validity of the Lowenstein Communication Scale.

Background/objectives: The Lowenstein Communication Scale (LCS) is a tool for the evaluation of communicative performance in patients with disorders of consciousness (DOC). This study investigated the reliability and validity of the LCS.

Methods: We evaluated 23 inpatients with unresponsive wakefulness syndrome (UWS) and 18 in a minimally conscious state (MCS), at admission to a Consciousness Rehabilitation Department and one month later. The evaluations included assessments of LCS by two raters, and of the Coma Recovery Scale-Revised (CRS-R) by one rater.

Results: Total inter-rater agreement in LCS task scoring was found in 58-100% of the patients. Cohen's kappa values were >0.6 for most tasks. High correlations were found between the two raters on total scores and most subscales (r = 0.599-1.000, p < 0.001), and the differences between them were small. LCS subscales and total score intraclass correlations (ICC) were high. Internal consistency was acceptable (Cronbach's α > 0.7) for most LCS subscales and total scores. Moderate to strong correlations were found between LCS and CRS-R scores (r = 0.554-0.949, p < 0.05), and the difference in responsiveness between LCS and CRS-R was non-significant.

Conclusions: The findings indicate that the LCS is reliable and valid, making it a valuable clinical and research assessment tool for patients with DOC.