Comparison of mental-status scales for predicting mortality on the general wards

• Published in: Journal of hospital medicine Vol. 10; no. 10; pp. 658 - 663
• Main Authors: Zadravecz, Frank J., Tien, Linda, Robertson-Dick, Brian J., Yuen, Trevor C., Twu, Nicole M., Churpek, Matthew M., Edelson, Dana P.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-10-2015; Frontline Medical Communications
• Subjects: Adult; Aged; Cohort Studies; Critical Illness; Female; Glasgow Coma Scale; Hospital Mortality; Hospital Rapid Response Team; Hospital Units; Humans; Male; Middle Aged; Neurologic Examination - methods; Retrospective Studies
• ISSN: 1553-5592; 1553-5606
• DOI: 10.1002/jhm.2415

BACKGROUND
Altered mental status is a significant predictor of mortality in inpatients. Several scales exist to characterize mental status, including the AVPU (Alert, responds to Voice, responds to Pain, Unresponsive) scale, which is used in many early‐warning scores in the general‐ward setting. The use of the Glasgow Coma Scale (GCS) and Richmond Agitation Sedation Scale (RASS) is not well established in this population.
OBJECTIVE
To compare the accuracies of AVPU, GCS, and RASS for predicting inpatient mortality.
DESIGN
Retrospective cohort study.
SETTING
Single, urban, academic medical center.
PARTICIPANTS
Adult inpatients on the general wards.
MEASUREMENTS
Nurses recorded GCS and RASS on consecutive adult hospitalizations. AVPU was extracted from the eye subscale of the GCS. We compared the accuracies of each scale for predicting in‐hospital mortality within 24 hours of a mental‐status observation using area under the receiver operating characteristic curves (AUC).
RESULTS
There were 295,974 paired observations of GCS and RASS obtained from 26,873 admissions; 417 (1.6%) resulted in in‐hospital death. GCS and RASS more accurately predicted mortality than AVPU (AUC 0.80 and 0.82, respectively, vs 0.73; P < 0.001 for both comparisons). Simultaneous use of GCS and RASS produced an AUC of 0.85 (95% confidence interval: 0.82‐0.87, P < 0.001 when compared to all 3 scales).
CONCLUSIONS
In ward patients, both GCS and RASS were significantly more accurate predictors of mortality than AVPU. In addition, combining GCS and RASS was more accurate than any scale alone. Routine tracking of GCS and/or RASS on general wards may improve the accuracy of detecting clinical deterioration. Journal of Hospital Medicine 2015;10:658–663. © 2015 Society of Hospital Medicine