Validation of a consciousness level scale for palliative care.

The main objective of this study is to validate a Consciousness Scale for palliative care. The scale was named Consciousness Scale for palliative care (CSPC). The validation had two phases: 1) face validity--the scale was assessed by seven healthcare professionals, both doctors and nurses, experienced in palliative care; 2) reliability and construct validity--performed by four investigators, two nurses and two doctors. The construct validation was performed by comparing the CSPC with a Visual Analogue Scale (VAS) of 100 mm, anchored in the terms 'awake' and 'unarousable', and then with the Glasgow Coma Scale (GCS). In this study, all four observers completed 44 periods of observation relative to 38 patients resulting in a total of 176 observations. In the phase of face validation, there were no discrepancies in relation to the issue: the scale provides measures for measurement; the scale can be useful to clinical practice; the scale can improve communication among professionals and the scale is easy to use. As a measure of internal consistency, Cronbach's alpha was found to be very high (0.99). The inter-rater reliability was also very high with an intraclass correlation coefficient of 0.99 (P < 0.001). The correlation of the CSPC to the VAS was 0.94 (P < 0.001) and the CSPC to the GCS was -0.82 (P < 0.001). The CSPC can be a very useful tool for assessing consciousness in palliative care patients. It is very ease to use, not time consuming and can be used with minimal training. Communication between professionals can be improved in the clinical setting and in the research environment.