The reliability and validity of the PALOC-s: a post-acute consciousness level scale for the assessment of young patients with prolonged disturbed consciousness after brain injury.
Eilander, H.J., van de Wiel, M., Wijers, M., van Heugten, C.M., Buljevac, D., Lavrijsen, J.C., Hoenderdaal, P.L., de Letter-van der Heide, L., Wijnen, V.J., Scheirs, J.G., de Kort, P.L., & Prevo, A.J.
1 January 2009Abstract
The aim of the study was to validate the post-acute level of
Consciousness Scale (PALOC-s) for use in assessing consciousness levels of patients with severe brain injury in a vegetative state or in a minimally conscious state. A cohort of 44 sequentially admitted patients (aged 2 to 25 years), who were treated in an early intensive neurorehabilitation program, was included in the study. Each patient was examined once every two weeks using the Western Neuro Sensory Stimulation Profile (WNSSP) and the Disability Rating Scale (DRS), resulting in 327 studies (all on video). To determine the reliability of the PALOCs, six observers assessed one videotape of each patient. One of the observers assessed the same tapes a second time, 3-4 months later. Validity was determined by correlating 100 assessments from one observer with the scores on the WNSSP and the DRS. To determine the responsiveness of the PALOC-s, the magnitude of the change between the scores of the first and last exams was calculated. The correlations between observers and agreement scores ranged between .82 and .95. The intra-observer correlation and agreement scores ranged between .94 and .96. Correlations with the
WNSSP ranged between .88 and .93, and with the DRS between .75 and .88. Responsiveness was significantly high (t 1/4 8.2), with a standardized effect size of 1.30.
It is concluded that the PALOC-s is a reliable, valid and responsive observational instrument, provided that it is administered after a structured assessment by an experienced and trained clinician. The PALOC-s is feasible for use in clinical treatment, but also in outcome research.
Keywords
Level of consciousness; Minimal conscious state; Reliability;
Responsiveness; Severe brain injury; Validity; Vegetative state.