Title
Inter-Tester Reliability and Agreement of the Cumulated Ambulation Score in Stroke patients: The InTRO-CAS-stroke study

Objective
To examine the inter-tester reliability of the total Cumulated Ambulation Score (CAS) and the three activities of the CAS, and to define limits for the smallest change in basic mobility that indicates a real change in patients with stroke.

Methods
An intertester reliability study. Setting: Participants: 60 participants from a specialized stroke unit with a mean age of 69.10 ± 13.23 years. The CAS describes a patient's independency in three activities – (1) getting in and out of bed, (2) sit to stand from a chair, and (3) walking ability and was assessed by two independent physiotherapists at median day 3 poststroke. Each activity was assessed on a three-point ordinal scale from 0 (not able to) to 2 (independent). The cumulated score for each activity provides a total CAS from 0 to 6, with 6 indicating independent basic mobility. Relative and absolute reliability was evaluated using weighted kappa, the standard error of measurement (SEM) and minimal detectable change (MDC).

Results
The weighted kappa for the total CAS score was 0.816 and ranged from 0.733 to 0.904 for the 3 CAS activities. The SEM and the MDC of the total CAS was 0.37 and 1.03 respectively.

Conclusions
The intertester reliability of the CAS is almost perfect, and a change of 1 CAS point for the total CAS indicates a real change in basic mobility, at group level and for an individual patient with stroke

Clinicaltrials.gov identifier
NCT05601089