Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command following Scale in Japan

Masachika Niimi; Yuki Hasegawa; Kensuke Taguchi; Hiroshi Ito; Kenji Higuchi; Masahiro Abo

doi:10.4266/acc.000936

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Original Article Neurology Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command following Scale in Japan: Acute and Critical Care 2026;41(3):621-630.
DOI: https://doi.org/10.4266/acc.000936
Published online: July 23, 2026

Masachika Niimi¹

, Yuki Hasegawa^2,3

, Kensuke Taguchi³

, Hiroshi Ito⁴

, Kenji Higuchi³

, Masahiro Abo^2,4

¹Department of Rehabilitation Medicine, Nihon University School of Medicine, Tokyo, Japan

²Department of Rehabilitation Medicine, The Jikei University School of Medicine, Tokyo, Japan

³Department of Rehabilitation, The Jikei University Kashiwa Hospital, Kashiwa, Japan

⁴Department of Rehabilitation, The Jikei University Hospital, Tokyo, Japan

Corresponding author: Masachika Niimi Department of Rehabilitation Medicine, Nihon University School of Medicine, 30-1, Oyaguchi Kami-cho, Itabashi-ku, Tokyo 173-8610, Japan Tel: +81-3-3972-8111 Fax: +81-3-3972-0018 Email: pomardon2010@gmail.com

• Received: January 29, 2026 • Revised: March 4, 2026 • Accepted: March 5, 2026

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Abstract
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
KEY MESSAGES
NOTES
REFERENCES

Abstract

Background
We developed a novel evaluation for delirium and cognitive function named Jikei Command following Scale (JCoS). The objective of this study was to examine the reliability and validity of the JCoS.
Methods
JCoS consists of 8 subitems (1, hand holding and releasing; 2, plantar dorsiflexion; 3, eye opening and closing; 4, visual pursuit; 5, mouth opening; 6, neck movement; 7, two-step command; and 8, movement sustainment). Fifty patients in the intensive care unit (ICU) participated in this study. Cronbach's alpha coefficient of JCoS total score was used for internal consistency. Intraclass correlation coefficient (ICC case 2) was used for inter-examiner reliability. The kappa coefficients for each subitem score were calculated. Concurrent validity was examined by correlation with Confusion Assessment Method for the ICU (CAM-ICU) and intensive care delirium screening checklist (ICDSC). Mini-Mental State Examination (MMSE) 2 weeks after leaving the ICU was used for predictive validity.
Results
The Cronbach's alpha coefficient of the JCoS Score was 0.967. The ICC (2,1) of the JCoS Score was 0.933. The kappa coefficients of each subitem were 0.668 for 1, 0.534 for 2, 0.346 for 3, 0.721 for 4, 0.474 for 5, 0.625 for 6, 0.724 for 7, and 0.709 for 8. Correlation coefficient between JCoS and the ICDSC was –0.843, and the correlation ratio between JCoS and CAM-ICU was –0.881. Correlation coefficient between JCoS and MMSE was 0.632.
Conclusions
These results suggest that JCoS has sufficient reliability and validity for evaluating delirium and cognitive function in ICU.
Key Words: cognitive dysfunction; delirium; intensive care units; muscle weakness; rehabilitation

INTRODUCTION

Recent developments in intensive care medicine have improved survival rates of critically ill patients [1]. However, in critically ill patients admitted to the intensive care unit (ICU), physical [2] and cognitive dysfunction and mental health problems due to post-intensive care syndrome (PICS) [3] can reduce their levels of activities of daily living (ADL) [4]. In particular, it has been reported that cognitive dysfunction in PICS remains in approximately 60% of patients at ICU discharge and in 43% of patients even 12 months after ICU discharge [5]. Cognitive impairment is a major factor that necessitates assistance [6]. Previous studies have reported an association between the duration of delirium during ICU stay and long-term cognitive decline [7,8] and between postoperative delirium in the perioperative period and postoperative cognitive dysfunction [9]. Thus, prevention of the onset and prolongation of delirium during ICU stay is the basis of treatment strategies for cognitive dysfunction in PICS. According to the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5), delirium is a disturbance in attention and awareness that represents an acute change from baseline and tends to fluctuate in severity, which is a direct physiological consequence of another medical condition, and is accompanied by an additional disturbance in cognition [10]. It has been reported that delirium occurs in about 30%–90% of patients in ICUs [11]. Inflammation in the brain and the development of abnormal neural networks are suggested as possible mechanisms for the development of ICU delirium [12]. The Society of Critical Care Medicine has provided countermeasures for ICU delirium based on the Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU (PADIS Guidelines) [13]. The PADIS Guidelines describe the ABCDEF bundle, a multidisciplinary, multicomponent non-pharmacological intervention approach to manage delirium. The intensive care delirium screening checklist (ICDSC) [14] and the Confusion Assessment Method for the ICU (CAM-ICU) [15] recommended in the PADIS Guidelines are used to assess delirium. Both instruments have a strong diagnostic aspect to assess the presence of delirium. However, it is difficult to measure the degree of delirium and cognitive dysfunction during ICU stay and their changes over time with treatment using the ICDSC and the CAM-ICU. The Mini-Mental State Examination (MMSE) [16], which is a well-used cognitive function assessment, requires the patient to verbally respond, write, and copy, and is often not suitable for the intensive care area. These limitations suggest that a new evaluation method for delirium and cognitive function in patients admitted to the ICU is highly desired in investigating the prevention of cognitive dysfunction and the effectiveness of treatment in PICS. Therefore, we focused on command following, which is presumed to be related to patients’ delirium and cognitive function, and developed the Jikei Command following Scale (JCoS), a new evaluation chart that can be administered in the ICU. This study aimed to examine the reliability and validity of the JCoS.

MATERIALS AND METHODS

This study was conducted in compliance with the principles of the Declaration of Helsinki and was approved by the Ethics Committee of the Jikei University School of Medicine (No. 28-114 (8357). Informed consent was obtained using an opt-out approach.

Participants

This study was conducted in a tertiary care hospital. Patients were enrolled between June 2018 and July 2019. Those who fulfilled the following criteria were included. (1) aged 18 years or older, (2) ICU stay of more than 24 hours, (3) with rating of –2 to +2 on the Richmond Agitation-Sedation Scale (RASS) [17] at the time of evaluation. Patients with uncontrolled psychiatric disorders, those who did not understand Japanese, and those with significant hearing or visual impairment were also excluded. Patients who died during hospitalization were excluded. Figure 1 shows the flowchart of the screening and selection process in this study. Upon admission to the ICU, the patients were provided with a document outlining the study information and their families were provided in the waiting room. The patients and their families were informed that they were free to decline participation if they did not wish to participate in the study. To make the document easy to understand, it is written in simple language and large letters.

Evaluation Method of the JCoS

The selection of the JCoS assessment items was based on the following considerations: (1) applicability to patients under ventilatory management and assisted circulation management, (2) assessment of the whole body in the supine resting position, (3) assessment in a short period of time without the use of objects, and (4) measurement of changes over time as a scale assessment. Taking these into consideration, eight assessment items were selected: 1. hand holding and releasing, 2. plantar dorsiflexion, 3. eye opening and closing, 4. visual pursuit, 5. mouth opening, 6. neck movement, 7. two-step command, and 8. movement sustainment. The total score (0–24 points) of the patient's responses to the commands was used as the result of the JCoS assessment. Assessment items and procedures for the JCoS are shown in Table 1. For each command, if the command could not be performed with the first instruction, an example imitation was added with the second instruction. The command for 1. hand holding and releasing was “Please hold my hand and let go.” A score of 0 was given for “Not able,” 1 for “Partially able (e.g., possible to hold but not to release),” 2 for “Able with repeated command and example imitation,” and 3 for “Able to hold and release the hand repeatedly with verbal command alone." The command for 2. plantar dorsiflexion was “Please move your ankles.” A score of 0 was given for “Not able,” 1 for “Partially able,” 2 for “Able with repeated command and example imitation,” and 3 for “Able to perform plantar dorsiflexion repeatedly with verbal command alone.” The command for 3. eye opening and closing was “Please close your eyes and then open them.” A score of 0 was given for “Not able,” 1 for “Partially able (e.g., eyes can be opened, but not closed),” 2 for “Able with repeated command and example imitation,” and 3 for “Able to open and close the eyes repeatedly with verbal command alone.” The command for 4. visual pursuit was “Please follow my finger with your eyes.” A score of 0 was given for “Not able,” 1 for “Able to perform eye search movements (such as looking around with the eyes),” 2 for “Able to gaze (such as eye contact with the examiner) when spoken to,” and 3 for “Able to perform visual pursuit smoothly with a verbal command alone.” The command for 5. mouth opening was “Please open your mouth.” A score of 0 was given for “Not able,” 1 for “Partially able (e.g., weak lip movement),” 2 for “Able with repeated command and example imitation,” and 3 for “Able to open mouth repeatedly with verbal command alone.” The command for 6. neck movement was “Please shake your head from side to side.” A score of 0 was given for “Not able,” 1 for “Partially able (e.g., nodding),” 2 for “Able with repeated command and example imitation,” and 3 for “Able to perform neck movement repeatedly with verbal command alone.” The command for 7. two-step command was “Please squeeze and open your hand, and then move your ankle.” A score of 0 was given for “Not able,” 1 for “Partially able (e.g., move either the hand or ankle),” 2 for “Able with repeated command and example imitation,” and 3 for “Able to follow both elements of the two-step command with verbal commands alone.” In the command for 7, the patients need to memorize two movements and perform each in sequence, unlike command for 1 or 2, which requests one movement. The command for 8. movement sustainment was “Please close your eyes and count to 10, then open them.” A score of 0 is given for “Not able,” 1 for “Partially able (e.g., able to hold eye closure for at least a few seconds),” 2 for “Able to hold eye closure with repeated voice prompts (e.g., ‘Not yet, almost there,’ etc.),” and 3 for “Able to hold eye closure and open the eyes after 10 seconds with verbal command alone.” The main features of 7. two-step command and 8. movement sustainment are that they include the elements of “memory retention” and “sustained attention”, respectively, in addition to command following. In this study, the total JCoS Score and the subitem scores were evaluated.

Reliability

The reliability of the JCoS Score was examined in terms of internal consistency and inter-examiner reliability. The JCoS assessments were performed within 48 hours of the patient's admission to the ICU. The JCoS was assessed independently by one physician and by one occupational therapist. The interval between each JCoS administration was limited to 6 hours to allow for clinical feasibility. Assessments were performed between 9:00 and 12:00 or between 13:00 and 16:00, taking into account circadian fluctuation in delirium, especially exacerbation associated with nocturnal delirium.

Validity

Concurrent validity and predictive validity were examined as criterion-related validity of the JCoS. The ICDSC and the CAM-ICU were used to assess concurrent validity. The ICDSC and CAM-ICU assessments were conducted by other occupational therapists immediately after an occupational therapist's JCoS assessment. The MMSE 2 weeks after leaving the ICU was used to evaluate predictive validity. The ICDSC is a screening tool for delirium based on the revised DSM-IV [17], and the reliability and validity of the Japanese version have been verified [18]. The eight items include (1) altered level of consciousness, (2) inattention, (3) disorientation, (4) hallucination, delusion, or psychosis, (5) psychomotor agitation or retardation, (6) inappropriate mood or speech, (7) sleep wake cycle disturbance, and (8) fluctuations, each given a score of 1 or 0, with a total score of 4 or more being considered delirium. In this study, the total score measured at the initial occupational therapy evaluation was used. The CAM-ICU is a delirium assessment designed for patients who are unable to speak, such as those on ventilators [15], and the reliability and validity of the Japanese version have been verified [19]. There are two steps: an assessment of agitation using the RASS followed by a delirium assessment. If the RASS is –4 or –5, the delirium assessment is not performed because the patient is considered comatose. If the RASS is –3 to +4, the delirium assessment is performed. The delirium assessment consists of (Feature 1) acute onset of mental status changes or fluctuating course, (Feature 2) inattention, (Feature 3) disorganized thinking, and (Feature 4) altered level of consciousness. Delirium is diagnosed when Features 1 and 2 with either 3 or 4 are present. The MMSE is a simple diagnostic tool for dementia and is widely used [16]. The MMSE consists of 11 items assessing orientation, memory, calculation, verbal ability, response to a three-stage command, and visuospatial ability. The maximum score is 30, with a score of 26 or less indicating a possibility of mild cognitive impairment and a score of 23 or less indicating a strong possibility of dementia. Since it was difficult to measure the MMSE while the patients were in the ICU, the total MMSE score two weeks after discharge from the ICU was used as a measure of cognitive function after discharge from the ICU. The ICDSC, the CAM-ICU, and the MMSE were evaluated by other occupational therapists blind to the JCoS results administered by a physician and an occupational therapist. JCoS evaluators were blinded to ICDSC and CAM-ICU results.

Statistical Analysis

To verify internal consistency, the Cronbach's α coefficient of the physician-measured JCoS Score was calculated. To verify inter-examiner reliability, the intraclass correlation coefficient (ICC case 2) was calculated for the JCoS Score measured on the same day by the physician and the occupational therapist. The κ coefficients for each subitem score were also calculated. Cronbach's α coefficient ranges from 0 to 1.0, with a value of 0.7 or higher generally considered desirable [20]. The criteria for judging ICC (2,1) and κ coefficients were as follows: κ < 0.00: poor; κ = 0.00–0.20: slight; κ = 0.21–0.40: fair; κ = 0.41–0.60: moderate; κ = 0.61–0.80: substantial; and κ > 0.81: almost perfect [21].

For concurrent validity, Spearman's rank correlation coefficient (rs) between the physician-measured JCoS Scores and the ICDSC scores was calculated. The correlation ratio (η) between the physician-measured JCoS Scores and the CAM-ICU scores was also calculated. To test predictive validity, Spearman's rank correlation coefficient (rs) was calculated between the physician-measured JCoS Scores and the MMSE scores obtained two weeks after ICU discharge. Effect sizes were interpreted as fairly weak at 0 to 0.1, weak at 0.1 to 0.3, moderate at 0.3 to 0.5, and strongly correlated at 0.5 to 1.0 [22]. The receiver operating characteristic (ROC) curve of the JCoS for detecting delirium status defined by ICDSC and CAM-ICU was constructed and the areas under the ROC curves (AUCs) were calculated.

The required sample size was calculated as N=15 for detecting adequate Cronbach's alpha based on the formula presented in the review paper on sample size determination [23], assuming a null hypothesis Cronbach's alpha of 0.0, an expected Cronbach's alpha of 0.70, a type I error of 0.05, and a statistical power of 0.80. The required sample size was calculated as N=49 for detecting good ICC, with an expected ICC of 0.80, a null hypothesis ICC of 0.60, a type I error of 0.05, a statistical power of 0.80, and two raters, using R statistics (Package “ICC.Sample.Size,” version 1.0) [24]. The required sample size was calculated as N=33 for strong correlation with ICDSC, CAM-ICU, and MMSE, with an expected Spearman's rank correlation coefficient of 0.50, a type I error of 0.05, and a statistical power of 0.80.

Unless otherwise stated, IBM SPSS statistics version 28 (IBM Corp.) was used for statistical analyses, and the statistical significance was set at 5%.

RESULTS

The clinical characteristics of the patients are shown in Table 2. The mean age was 68.6±13.5 years, and there were 18 women and 32 men. Primary diseases on ICU admission included cardiovascular disease in 13 patients, respiratory disease in 13 patients, neurological disease in 4 patients, neoplastic disease in 4 patients, other medical diseases in 12 patients, and other surgical illnesses in 4 patients. The mean number of days of ICU stay was 12.5±10.7 days. The time interval between the two JCoS assessments was 119.4±78.5 minutes.

The results of each rating scale are shown in Table 3. The median JCoS Score as assessed by the physician was 22 (interquartile range, 19–24) and the median JCoS Score as assessed by the occupational therapist was 23 (interquartile range, 18–24). The MMSE was administered in 38 patients after discharge from the ICU. We could not administer the MMSE on the remaining patients due to sudden hospital transfer.

The results on the reliability of the JCoS are shown in Table 4. The Cronbach's α coefficient of the JCoS Score was 0.967, and good internal consistency was confirmed. The ICC (2,1) of the JCoS Score was 0.933 (P<0.001) and was judged to be “almost perfect”. The κ coefficients of each subitem were 0.668 (95% CI, 0.403–0.933) for 1. hand squeezing and releasing, 0.534 (95% CI, 0.225–0.844) for 2. plantar dorsiflexion, 0.346 (95% CI, 0.064–0.628) for 3. eye opening and closing, 0.721 (95% CI, 0.550–0.892) for 4. visual pursuit, 0.474 (95% CI, 0.253–0.696) for 5. mouth opening, 0.625 (95% CI, 0.303–0.946) for 6. neck movement, 0.724 (95% CI, 0.598–0.851) for 7. two-step command, and 0.709 (95% CI, 0.586–0.833) for 8. movement sustainment (P<0.001 for all).

Figure 2 shows the scatterplots between the JCoS Scores and the scores of the ICDSC, the CAM-ICU, and the MMSE at 2 weeks after ICU discharge. The effect size (rs) between the JCoS and the ICDSC was –0.843 (P<0.001), and the correlation ratio (η) between the JCoS Scores and the CAM-ICU scores was –0.881 (P<0.001), both showing a strong negative correlation. In addition, the effect size (rs) between the JCoS Scores and the MMSE scores at 2 weeks after ICU discharge was 0.632 (P<0.001), showing a strong positive correlation.

Figure 3 shows the ROC curve of the JCoS for detecting delirium status defined by ICDSC and CAM-ICU. To detect delirium status defined by ICDSC, the AUC was 0.948 (95% CI, 0.883–1.013), with an optimal cutoff value for JCoS of 22.5, sensitivity of 0.821, and specificity of 0.999. To detect delirium status defined by CAM-ICU, the AUC was 0.985 (95% CI, 0.960–1.010), with an optimal cutoff value for JCoS of 21.5, sensitivity of 0.905, and specificity of 0.966.

DISCUSSION

In this study, a high value of Cronbach's α coefficient demonstrated JCoS Score has good internal consistency. The ICC (2,1) of the JCoS Score was judged to be “almost perfect,” indicating high inter-examiner reliability. A strong negative correlation was found with the ICDSC and the CAM-ICU indicating good concurrent validity, and a strong positive correlation was found with the MMSE scores two weeks after discharge from ICU indicating adequate predictive validity. Accordingly, the JCoS was shown to have criterion-related validity for assessing delirium and future cognitive function in patients in the ICU. Based on our results, it is expected that the JCoS can be used as a reliable assessment instrument in both clinical and research settings. ICU patients represent a heterogeneous population with diverse underlying conditions. Therefore, the Society of Critical Care Medicine’s international consensus emphasized the importance of diagnosis-independent and standardized approaches for assessing PICS [25]. In this study, we prioritized creating a general-purpose evaluation scale rather than a disease-specific one, and did not limit the diseases of the patients. Although disease heterogeneity could potentially reduce reliability and validity, the JCoS demonstrated good internal consistency, interrater reliability, and criterion-related validity.

The Consensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist, a standard international criterion for scale research, proposes the need to verify the reliability and validity of scientific rating scales [26]. Based on the COSMIN checklist, the JCoS was shown to have good internal consistency, inter-rater reliability, concurrent validity, and predictive validity at this stage, indicating that it is an adequate scientific assessment instrument. The lowest item was 3. eye opening and closing (κ coefficient: 0.346), and the largest was 7. two-step instruction (κ coefficient: 0.724), showing variability in κ coefficients from “fair” to “substantial”. Variabilities in κ coefficients were also observed in previous studies that verified the reliability of the Japanese version of the ICDSC (κ coefficient: minimum 0.22–maximum 0.55) [18] and the Japanese version of the CAM-ICU (κ coefficient: minimum 0.22–maximum 0.90) [19], suggesting that target diseases and difference in interpretation among examiners may have had an influence on the reliability. It seems that education and training on JCoS evaluation methods are needed to improve the reliability in the future. Taking these into account, it would be preferable to use the JCoS subitems after controlling the subjects and evaluation methods if only the subitems will be used in clinical interpretation and research.

The capability of the JCoS to measure changes over time in the degree of delirium and cognitive dysfunction is an element that can contribute to the realization of regular delirium assessments, improving cognition and optimizing mobility in the ABCDEF bundle. The eight evaluation items are assumed to include comprehensive and multifaceted elements such as head and facial movement, limb movement, memory retention, and sustained attention, and the items will provide novel information that are not included in the existing evaluations. If we are to apply the current results in clinical practice, a high JCoS Score would suggest high command following ability, suggesting a smaller possibility of delirium and cognitive dysfunction, which in turn indicates that relatively advanced task training can be performed. On the other hand, if the JCoS Score is low and the command following ability is low, then the possibility of delirium and cognitive dysfunction is high, and it can be judged that task training is difficult. In this way, it is expected that the JCoS will function as the basis for the application of rehabilitation and the selection of training content at ICU, including cognitive function training and early mobilization. Álvarez et al. [27] examined the effects of early mobilization by physical therapists and cognitive and ADL training by occupational therapists, on ICU delirium in a randomized controlled trial and reported that it was effective in preventing the onset of delirium and cognitive decline. If the JCoS scale developed in this study can be used to evaluate patients' delirium, cognitive function, and command following ability in detail, and if this allows the selection of training content, this will lead to an efficient implementation of rehabilitation tailored to the patient.

This study has several limitations. First, the number of cases was small and the diseases and treatments were biased; therefore, the generalizability of the results may be limited. In order to generalize JCoS, it is necessary to conduct studies involving a larger number of cases and minimize bias in diseases and treatments. In addition, this study did not examine scale characteristics such as interpretability and construct validity [26]. The interpretability and construct validity need to be verified and improved in order to develop more accurate rating scales. In clinical practice emphasizing feasibility, criterion-related validity often takes precedence over construct validity, but construct validity is also important in developing new assessment scales to obtain a theoretical construct [28]. More than 200 cases are required to verify construct validity [29]. Lastly, many patients were admitted to our hospital's ICU on an emergency basis, making it difficult to obtain data on cognitive impairment before admission. Therefore, this study cannot distinguish whether delirium and cognitive impairment were present before or after admission.

In conclusion, the results of this study showed that the JCoS is a reliable and valid method of assessing the command following ability for delirium and cognitive function in patients admitted to the ICU.

KEY MESSAGES

▪ A novel evaluation for delirium and cognitive function in the intensive care unit (ICU) was developed based on ability of command following. The evaluation is easy to perform and requires no equipment.

▪ The evaluation has good internal consistency. The intraclass correlation coefficient case 2 (2,1) of the evaluation indicates high inter-examiner reliability.

▪ The evaluation has a strong negative correlation with the intensive care delirium screening checklist and Mini-Mental State Examination (MMSE), indicating good concurrent validity. In addition, a strong positive correlation was found with the MMSE scores 2 weeks after discharge from ICU indicating adequate predictive validity.

NOTES

CONFLICT OF INTEREST

No potential conflict of interest relevant to this article was reported.

FUNDING

This work was partially supported by JSPS KAKENHI Grant Number 22K11379.

ACKNOWLEDGMENTS

None.

AUTHOR CONTRIBUTIONS

Conceptualization: MN, HI. Data curation: YH, KT. Formal analysis: MN. Funding acquisition: YH. Methodology: MN, KT. Project administration: MN, YH. Visualization: KT. Writing – original draft: MN, KT. Writing – review & editing: KH, MA. All authors read and agreed to the published version of the manuscript.

Figure 1.

Flowchart of the screening and selection process. ICU: intensive care unit.

Figure 2.

The validity of the JJikei Command following Scale (JCoS). (A) Relationship between the JCoS Scores and the intensive care delirium screening checklist (ICDSC) scores. The correlation coefficient was –0.843 (P<0.001). (B) Relationship between the JCoS Scores and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) scores. The correlation ratio (η) was v0.881 (P<0.001). (C) Relationship between the Mini-Mental State Examination (MMSE) scores 2 weeks after ICU discharge and the JCoS Scores. The correlation coefficient was 0.632 (P<0.001).

Figure 3.

The receiver operating characteristic (ROC) curve of the Jikei Command following Scale (JCoS) for detecting delirium. (A) To detect delirium status defined by intensive care delirium screening checklist, the area under the ROC curve (AUC) was 0.948 (95% CI, 0.883–1.013), with an optimal cutoff value for JCoS of 22.5, sensitivity of 0.821, and specificity of 0.999. (B) To detect delirium status defined by Confusion Assessment Method for the Intensive Care Unit, the AUC was 0.985 (95% CI, 0.960–1.010), with an optimal cutoff value for JCoS of 21.5, sensitivity of 0.905, and specificity of 0.966.

Table 1.

Assessment items and procedures for the Jikei Command following Scale

Items and commands		Response	Score
1	Hand holding and releasing “Please hold your hand and let go.”	Not able	0	□
		Partially able (e.g., possible to hold but not to release)	1	□
		Able with repeated command and example imitation	2	□
		Able to hold and release the hand repeatedly with verbal command alone	3	□
2	Plantar dorsiflexion “Please move your ankles.”	Not able	0	□
		Partially able	1	□
		Able with repeated command and example imitation	2	□
		Able to perform plantar dorsiflexion repeatedly with verbal command alone	3	□
3	Eye opening and closing “Please close your eyes and then open them.”	Not able	0	□
		Partially able (e.g., eyes can be opened, but not closed)	1	□
		Able with repeated command and example imitation	2	□
		Able to open and close the eyes repeatedly with verbal commands alone	3	□
4	Visual pursuit “Please follow my finger with your eyes.”	Not able	0	□
		Able to perform eye search movements (such as looking around with the eyes)	1	□
		Able to gaze (such as eye contact with the examiner) when spoken to	2	□
		Able to perform visual pursuit smoothly with verbal command alone	3	□
5	Mouth opening “Please open your mouth.”	Not able	0	□
		Partially able (e.g., weak lip movement)	1	□
		Able with repeated command and example imitation	2	□
		Able to open mouth repeatedly with verbal command alone	3	□
6	Neck movement “Please shake your head from side to side.”	Not able	0	□
		Partially able (e.g., nodding)	1	□
		Able with repeated command and example imitation	2	□
		Able to perform neck movement repeatedly with verbal command alone	3	□
7	Two-step command "Please hold and open your hand, and then move your ankles.”	Not able	0	□
		Partially able (e.g., move either the hand or ankle)	1	□
		Able with repeated command and example imitation	2	□
		Able to follow both elements of the two-step command with verbal command alone	3	□
8	Movement sustainment “Please close your eyes and count to 10, then open them.”	Not able	0	□
		Partially able (e.g., able to hold eye closure for at least a few seconds)	1	□
		Able to hold eye closure with repeated voice prompts (e.g., ‘Not yet, almost there,’ etc.)	2	□
		Able to hold eye closure and open the eye after 10 seconds with verbal command alone	3	□
Total score for items 1 to 8			____/ 24

Table 2.

Clinical characteristics of the patients

Variable	Value
Age (yr)	68.6±13.5
Sex
Female	18 (36.0)
Male	32 (64.0)
APACHE Ⅱ score	19.1±6.4
Main disease for ICU admission
Cardiovascular	13 (26.0)
Respiratory	13 (26.0)
Neurological	4 (8.0)
Tumor	4 (8.0)
Internal (other than above)	12 (24.0)
Surgical (other than above)	4 (8.0)
Use of sedatives and/or analgesics (%)
Sedatives	4 (8.0)
Analgesics	10 (20.0)
Sedatives and analgesics	14 (28.0)
None	22 (44.0)
Day in ICU (day)	12.5±10.7

Values are presented as mean±standard deviation or number (%).

APACHE: Acute Physiology and Chronic Health Evaluation; ICU: intensive care unit.

Table 3.

The results of each evaluation scale

Evaluation scale	Value
JCoS Score by medical doctor	22 (19–24)
JCoS Score by occupational therapist	23 (18–24)
ICDSC	4 (2–5.25)
CAM-ICU (positive:negative)	21 (42.0):29 (58.0)
MMSE (2 weeks after leaving the ICU, n=38)	26 (22–30)

Values are presented as median (interquartile range) or number (%).

JCoS: Jikei Command following Scale; ICDSC: intensive care delirium screening checklist; CAM-ICU: Confusion Assessment Method for the Intensive Care Unit; MMSE: Mini-Mental State Examination.

Table 4.

The reliability of the JCoS

	Value
JCoS Score	κ coefficient	95% CI
Cronbach’s alpha	0.967
ICC (2,1)	0.933^a)
JCoS subitem
Hand holding and releasing	0.668^a)	0.403–0.933
Plantar dorsiflexion	0.534^a)	0.225–0.844
Eye opening and closing	0.346^a)	0.064–0.628
Visual pursuit	0.721^a)	0.550–0.892
Mouth opening	0.474^a)	0.253–0.696
Neck movement	0.625^a)	0.303–0.946
Two-step command	0.724^a)	0.598–0.851
Movement sustainment	0.709^a)	0.586–0.833

JCoS: Jikei Command following Scale; ICC: intraclass correlation coefficient.

^a)P<0.001.

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Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command following Scale in Japan

Acute Crit Care. 2026;41(3):621-630. Published online July 23, 2026

DOI: https://doi.org/10.4266/acc.000936

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Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command following Scale in Japan

Figure 1. Flowchart of the screening and selection process. ICU: intensive care unit.

Figure 2. The validity of the JJikei Command following Scale (JCoS). (A) Relationship between the JCoS Scores and the intensive care delirium screening checklist (ICDSC) scores. The correlation coefficient was –0.843 (P<0.001). (B) Relationship between the JCoS Scores and the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) scores. The correlation ratio (η) was v0.881 (P<0.001). (C) Relationship between the Mini-Mental State Examination (MMSE) scores 2 weeks after ICU discharge and the JCoS Scores. The correlation coefficient was 0.632 (P<0.001).

Figure 3. The receiver operating characteristic (ROC) curve of the Jikei Command following Scale (JCoS) for detecting delirium. (A) To detect delirium status defined by intensive care delirium screening checklist, the area under the ROC curve (AUC) was 0.948 (95% CI, 0.883–1.013), with an optimal cutoff value for JCoS of 22.5, sensitivity of 0.821, and specificity of 0.999. (B) To detect delirium status defined by Confusion Assessment Method for the Intensive Care Unit, the AUC was 0.985 (95% CI, 0.960–1.010), with an optimal cutoff value for JCoS of 21.5, sensitivity of 0.905, and specificity of 0.966.

Figure 1.

Figure 2.

Figure 3.

Evaluation for delirium and cognitive function in intensive care unit: reliability and validity of the Jikei Command following Scale in Japan

Items and commands		Response	Score
1	Hand holding and releasing “Please hold your hand and let go.”	Not able	0	□
		Partially able (e.g., possible to hold but not to release)	1	□
		Able with repeated command and example imitation	2	□
		Able to hold and release the hand repeatedly with verbal command alone	3	□
2	Plantar dorsiflexion “Please move your ankles.”	Not able	0	□
		Partially able	1	□
		Able with repeated command and example imitation	2	□
		Able to perform plantar dorsiflexion repeatedly with verbal command alone	3	□
3	Eye opening and closing “Please close your eyes and then open them.”	Not able	0	□
		Partially able (e.g., eyes can be opened, but not closed)	1	□
		Able with repeated command and example imitation	2	□
		Able to open and close the eyes repeatedly with verbal commands alone	3	□
4	Visual pursuit “Please follow my finger with your eyes.”	Not able	0	□
		Able to perform eye search movements (such as looking around with the eyes)	1	□
		Able to gaze (such as eye contact with the examiner) when spoken to	2	□
		Able to perform visual pursuit smoothly with verbal command alone	3	□
5	Mouth opening “Please open your mouth.”	Not able	0	□
		Partially able (e.g., weak lip movement)	1	□
		Able with repeated command and example imitation	2	□
		Able to open mouth repeatedly with verbal command alone	3	□
6	Neck movement “Please shake your head from side to side.”	Not able	0	□
		Partially able (e.g., nodding)	1	□
		Able with repeated command and example imitation	2	□
		Able to perform neck movement repeatedly with verbal command alone	3	□
7	Two-step command "Please hold and open your hand, and then move your ankles.”	Not able	0	□
		Partially able (e.g., move either the hand or ankle)	1	□
		Able with repeated command and example imitation	2	□
		Able to follow both elements of the two-step command with verbal command alone	3	□
8	Movement sustainment “Please close your eyes and count to 10, then open them.”	Not able	0	□
		Partially able (e.g., able to hold eye closure for at least a few seconds)	1	□
		Able to hold eye closure with repeated voice prompts (e.g., ‘Not yet, almost there,’ etc.)	2	□
		Able to hold eye closure and open the eye after 10 seconds with verbal command alone	3	□
Total score for items 1 to 8			____/ 24

Variable	Value
Age (yr)	68.6±13.5
Sex
Female	18 (36.0)
Male	32 (64.0)
APACHE Ⅱ score	19.1±6.4
Main disease for ICU admission
Cardiovascular	13 (26.0)
Respiratory	13 (26.0)
Neurological	4 (8.0)
Tumor	4 (8.0)
Internal (other than above)	12 (24.0)
Surgical (other than above)	4 (8.0)
Use of sedatives and/or analgesics (%)
Sedatives	4 (8.0)
Analgesics	10 (20.0)
Sedatives and analgesics	14 (28.0)
None	22 (44.0)
Day in ICU (day)	12.5±10.7

Evaluation scale	Value
JCoS Score by medical doctor	22 (19–24)
JCoS Score by occupational therapist	23 (18–24)
ICDSC	4 (2–5.25)
CAM-ICU (positive:negative)	21 (42.0):29 (58.0)
MMSE (2 weeks after leaving the ICU, n=38)	26 (22–30)

	Value
JCoS Score	κ coefficient	95% CI
Cronbach’s alpha	0.967
ICC (2,1)	0.933^a)
JCoS subitem
Hand holding and releasing	0.668^a)	0.403–0.933
Plantar dorsiflexion	0.534^a)	0.225–0.844
Eye opening and closing	0.346^a)	0.064–0.628
Visual pursuit	0.721^a)	0.550–0.892
Mouth opening	0.474^a)	0.253–0.696
Neck movement	0.625^a)	0.303–0.946
Two-step command	0.724^a)	0.598–0.851
Movement sustainment	0.709^a)	0.586–0.833

Table 1. Assessment items and procedures for the Jikei Command following Scale

Table 2. Clinical characteristics of the patients

Values are presented as mean±standard deviation or number (%).

APACHE: Acute Physiology and Chronic Health Evaluation; ICU: intensive care unit.

Table 3. The results of each evaluation scale

Values are presented as median (interquartile range) or number (%).

JCoS: Jikei Command following Scale; ICDSC: intensive care delirium screening checklist; CAM-ICU: Confusion Assessment Method for the Intensive Care Unit; MMSE: Mini-Mental State Examination.

Table 4. The reliability of the JCoS

JCoS: Jikei Command following Scale; ICC: intraclass correlation coefficient.

P<0.001.