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. Author manuscript; available in PMC: 2016 Jun 1.
Published in final edited form as: J Crit Care. 2015 Jan 30;30(3):653.e1–653.e7. doi: 10.1016/j.jcrc.2015.01.017

Fig. 2.

Fig. 2

Percent of accurate responses (of 100%) on the 2-back condition of the N-back test across clinical populations, with a red horizontal line reflecting the performance of normal controls (mean, 88) from an external non-Vanderbilt data set. Data portrayed here are derived from the current study (in the case of critically ill patients) or from published literature (all other populations). In obtaining data from published literature, we sought—whenever possible—to choose patients broadly similar to our cohort with regard to age, in particular, and to use data that were broadly representative of relevant literature at large. Means and SDs across populations are as follows: CI: 76 (23.4), PD: 77 (7.7), MS: 83.47 (14.8), MCI: 81 (4), MTBI: 83 (7.0), and AD: 55 (4). CI indicates critically ill; PD, Parkinson disease; MS, multiple sclerosis; AD, Alzheimer disease.