Establishing Minimal Clinically Important Differences for the Cognitive and Linguistic Scale (CALS) in Pediatric Neurorehabilitation.

Objective: The Cognitive and Linguistic Scale (CALS) was developed to serially monitor cognitive recovery of children and young people after severe acquired brain injury, during inpatient rehabilitation. The CALS can be used to derive Cognitive Ability Estimates (CAE), which are Rasch-propertied (unidimensional, interval-scale) and therefore may be ideally applied for use in research including within the context of clinical trials. Here, we used established statistical distribution-based and expert consensus-based methods to estimate the minimal clinically important difference (MCID) for CAE derived from the CALS.

Design: Retrospective study.

Setting: Pediatric inpatient rehabilitation hospital.

Participants: 252 patients consecutively admitted for inpatient rehabilitation after acquired brain injury (46% traumatic brain injury); age at injury ranging from 1.9 to 21.6 years (median, 11.8 years).

Interventions: Not applicable.

Main Outcome Measures: MCID estimates.

Results: Together, results suggest a MCID of approximately 4-7 CAE units.

Conclusions: These data can be used to aid in the design and interpretation of clinical studies proposing to use the CALS CAE as an outcome measure.