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RehabMeasures Instrument

Disorders of Consciousness Scale

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Purpose

The DOCS is a structured clinical assessment tool that was developed to detect subtle changes in observable indicators of neurobehavioral functioning during recovery of consciousness following a severe traumatic brain injury. It can be used to monitor recovery of consciousness and evaluate the effects of interventions in order to better inform clinical decision-making and prognosis of recovery.

DOCS-25 is the most up-to-date and current version of this instrument. Four of the items from the DOCS-23 were removed and six new items were added with the purpose of improving the reliability and precision.

Link to Instrument

Acronym DOCS; DOCS-23 or DOCS-25

Cost

Free

Cost Description

Only cost associated with the administration kit. The average cost to create the kit is less than 100USD

Diagnosis/Conditions

  • Brain Injury Recovery

Populations

Key Descriptions

  • DOCS-23:
    -23 items
    -The rating scale describes levels of neurobehavioral integrity based on response to test stimuli. A score is assigned to the observed response for each test item. The rating scale points are:
    0: No Response
    1: Generalized Response
    2: Localized Response
    -Raw scores (0-46) are converted to interval level data (logits) and rescaled on a 0 to 100 point scale (0=min; 100=max)
    -Neuroanatomic structures important for function of each item are indicated in the manual
    -Repeated over time to compare to baseline assessment
    -7 Subscales of neurobehavioral functioning are included in the test items:
    1) Social Knowledge
    2) Taste & Swallowing
    3) Olfactory
    4) Proprioceptive
    5) Tactile
    6) Auditory
    7) Visual
  • DOCS-25:
    -25 items
    -Raw scores (0-50) are converted to interval level measures (logits) and rescaled on a 0 to 100 point scale (0=min;100=max)
    -The rating scale defines transitions from no response, to a generalized response, to a localized response to sensory stimuli
    -The items form four subscales of neurobehavioral functioning:
    1) Auditory-Language
    2) Somatosensory
    3) Visual
    4) Gustation/Olfaction

Number of Items

23 or 25

Equipment Required

  • Flavor extracts (vanilla, mint, orange)
  • Small amounts of juice, soda and/or a familiar taste
  • Cotton tipped applicators
  • Gloves
  • Towels and/or a washcloth
  • Two 3-dimensional objects (i.e. block, tennis ball, etc.)
  • Photographs of people familiar to the patient (familiar means that the patient knew the person for at least 1 year prior to the date of injury)
  • A hand-held mirror: 4 inches by 6 inches
  • Ice chips
  • Metal spoon
  • One mini vibrator massager
  • Feather
  • One can of pressurized air
  • Kitchen scrubs
  • Alcohol prep swabs
  • One 'do not disturb' sign
  • Pulse oximeter
  • One coaches whistle (only for DOCS-23)
  • One small/hand held school bell (only for DOCS-23)
  • One penlight (only for DOCS-23)
  • Hand warmer (only for DOCS-25)
  • Eye patch (only for DOCS-25)
  • Bite block (only for DOCS-25)
  • Sugar (only for DOCS-25)
  • Lemonade flavored drink mix powder (sour taste) (only for DOCS-25)
  • Toothbrush (only for DOCS-25)
  • Laminated Yes/No Cards (only for DOCS-25)

Time to Administer

40 minutes

40-60 minutes

Required Training

Training Course

Age Ranges

Adults

18 - 64

years

Instrument Reviewers

Initially reviewed by Erin Donnelly, PT, NCS and Karen McCulloch, PT, PhD, NCS and the TBI EDGE task force of the Neurology Section of the APTA in 7/2012; Updated by Jennifer Weaver, MA, OTR/L, CBIS; Elizabeth Elgin RN, BSN; Andrew Jones, BA; Theresa Louise-Bender Pape, DrPH, MA, CCC-SLP/L, FACRM; Ann Guernon, MS, CCC-SLP/L, CCRC; Trudy Mallinson, PhD, OTR/L, FAOTA, FACRM in January, 2019.

ICF Domain

Body Function

Professional Association Recommendation

Recommendations for use of the instrument from the Neurology Section of the American Physical Therapy Association’s  Spinal Cord Injury Taskforce (SCI EDGE) and Traumatic Brain Injury Taskforce (TBI EDGE). These recommendations were developed by a panel of research and clinical experts using a modified Delphi process.

For detailed information about how recommendations were made, please visit:  

Abbreviations:

 

HR

Highly Recommend

R

Recommend

LS / UR

Reasonable to use, but limited study in target group  / Unable to Recommend

NR

Not Recommended

 

Recommendations based on level of care in which the assessment is taken:

 

Acute Care

Inpatient Rehabilitation

Skilled Nursing Facility

Outpatient

Rehabilitation

Home Health

TBI EDGE

NR

R

LS

LS

LS

 

Recommendations for use based on ambulatory status after brain injury:

 

Completely Independent

Mildly dependant

Moderately Dependant

Severely Dependant

TBI EDGE

N/A

N/A

N/A

N/A

 

Recommendations for entry-level physical therapy education and use in research:

 

Students should learn to administer this tool? (Y/N)

Students should be exposed to tool? (Y/N)

Appropriate for use in intervention research studies? (Y/N)

Is additional research warranted for this tool (Y/N)

TBI EDGE

No

Yes

Yes

Not reported

Considerations

DOCS testing procedures allow for various response modes (gestures, verbal, eye gaze) in response to sensory stimuli at a localized or generalized level. Time of day may influence assessment results. It is recommended to control the external environment by reducing extraneous sensory input. Additionally, the patient should be continuously monitored to determine optimal positioning.

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Brain Injury

back to Populations

Standard Error of Measurement (SEM)

Brain Injury

DOCS-25: (Mallinson et al. 2016; n = 92. Mean age: 36.5 +/- 17 years. Time post injury: <90 days = 129, 91-180 days = 39, >180 days =4)

  • Standard Error of Measurements for all participants (n=92) = 4.14
  • Standard Error of Measurements for improvers (n=57) = 4.05
  • Standard Error of Measurements for non-improvers (n=35) = 3.6

Minimal Detectable Change (MDC)

Brain Injury

DOCS-25: (Mallinson et al. 2016; n = 92. Mean age: 36.5 +/- 17 years. Time post injury: <90 days = 129, 91-180 days = 39, >180 days =4)

Minimal Detectable Change with 95% Confidence Interval (MDC95)

  • MDC95 for entire group (n=92): 5.6 (using 0-100 transformed scale)
  • MDC95 for improvers (n=57): 5.5 (using 0-100 transformed scale)
  • MDC95 for non-improvers (n=57): 5.3 (using 0-100 transformed scale)

Minimally Clinically Important Difference (MCID)

Brain Injury

DOCS-25: (Mallinson et al. 2016; n = 92. Mean age: 36.5 +/- 17 years. Time post injury: <90 days = 129, 91-180 days = 39, >180 days =4)

Anchor-based MCID (GCS change of 2): 8.6 (using 0-100 transformed scale)

Distribution based Minimal Clinically Important Difference:

  • 0.20 SD: 2.6 (using 0-100 transformed scale)
  • 0.33 SD: 4.4 (using 0-100 transformed scale)
  • 0.50 SD: 6.6 (using 0-100 transformed scale)

Interrater/Intrarater Reliability

Brain Injury (CHI, anoxia, aneurysm, open-head injury, AV malformation, hemorrhage)

Docs-23: (Pape et al, 2005a; n= 95; mean age at injury= 36 years old; mean time post injury= not documented) 

  • Interrater reliability is based on ratings done by 44 clinicians (speech pathologists, PT, OT, RN, neuropsych doctoral candidates and respiratory therapists) where exact agreement on ratings was 54.4% (Pape et al, 2005a) A consensus process by American Congress of Rehabilitation Medicine, found fault with this method of reporting IRR (Seel et al., 2010). Pape et al.(2011) reported that the reliability is analogous to K=.95.

DOCS-25:

(Pape et al 2014; n = 39. Mean age & time since injury not reported for this subset of the sample of n=174)

       Inter-rater reliability

  • Excellent overall Inter-rater reliability: (ICC = 0.90)
  • Excellent Gustation/olfaction Inter-rater reliability: (ICC = 0.84)
  • Excellent Somatosensory Inter-rater reliability: (ICC = 0.91)
  • Excellent Auditory-language Inter-rater reliability: (ICC = 0.78)
  • Excellent Visual Inter-rater reliability: (ICC = 0.91) 

Internal Consistency

Brain Injury (CHI, anoxia, aneurysm, open-head injury, AV malformation, hemorrhage)

DOCS-23:(Pape et al, 2005a)

  • Excellent internal consistency (Cronbach’s alpha .85 for closed head injury, .77 for other head injury)

Brain Injury

DOCS-25:(Pape et al 2014; n = 174. Mean age: 36.5 + 17 years. Mean time post injury: 69.4 + 51.0 days)

  • Excellent internal consistency: Person separation reliability = 0.91, Separation Index = 3.22
  • Excellent: Cronbach’s Alpha: 0.86

Criterion Validity (Predictive/Concurrent)

Brain Injury (CHI, anoxia, aneurysm, open-head injury, AV malformation, hemorrhage)

DOCS-23:(Pape et al, 2005a)

  • True positive and negative rates for the baseline DOCS <48 or ≥ 48 indicate that the baseline DOCS detects recovery and lack of recovery of consciousness 71% and 68% of the time.
  • The AUC = .73 when comparing predicted recovery according to the baseline DOCS with actual recovery of consciousness indicates that the baseline DOCS accurately discriminates between these outcomes 73% of the time. 

Brain Injury, unconscious >28 days (closed head injury, anoxia, hemorrhage, aneurysm, blast injury):

DOCS-23: (Pape, et al., 2009; n= 113; mean age= 38 years old (TBI= 36 years old, OBI= 44.0 years old); mean days post injury= 48.3(TBI=45.93 days, OBI= 55.10 days))

  • Excellent predictive validity at 4 months post injury (Area Under Receiver Operating Characteristic Curve - AUC = .87)
  • Excellent predictive validity at 8 months post injury (AUC= .88)
  • Excellent predictive validity at 12 months post injury (AUC= .89 )

 

Brain Injury

DOCS-25:

Concurrent Validity: (Pape et al 2014; n = 174. Mean age: 36.5 + 17 years. Mean time post injury: 69.4 + 51.0 days)

  • Adequate concurrent validity using total DOCS-25 measures to GCS and CNC at baseline.
  • Poor concurrent validity using DOCS-25 subscales measures to GCS and CNC at baseline.

Concurrent Validity Results for DOCS-25 and Subscales

DOCS-25

GCS

CI

Total DOCS-25 measure (n=117)

ρ=0.55

0.39 to 0.70

Gustatory/Olfactory (n=108)

ρ=0.03

-0.17 to 0.22

Somatosensory (n=112)

ρ=0.16

-0.03 to 0.36

Visual (n=103)

ρ=0.27

0.08 to 0.46

Auditory-Language (n=110)

ρ=0.26

0.08 to 0.44

Reported as Spearman's rho. CI= 95% confidence interval.

Concurrent Validity of Results for DOCS-25 and Subscales

DOCS-25

CNC

CI

Total DOCS-25 measure (n=30)

ρ=-0.5

-0.87 to -0.13

Gustatory/Olfactory (n=23)

ρ=-0.18

-0.60 to 0.24

Somatosensory (n=23)

ρ=0.18

-0.24 to 0.59

Visual (n=23)

ρ=-0.1

-0.58 to 0.38

Auditory-Language (n=23)

ρ=0.22

-0.25 to 0.68

Reported as Spearman's rho. CNC= Coma/Near-Coma Scale. CI= 95% confidence interval.

Construct Validity

Brain Injury (CHI, anoxia, aneurysm, open-head injury, AV malformation, hemorrhage)

DOCS-23: (Pape, et al., 2005a)

  • The DOCS possibly has unidimensional hierarchic interval characteristics when used with persons with closed head injury.
  • The unidimensional hierarchic structure in Other Brain Injury has not been adequately established.

Brain Injury

DOCS-25: (Pape et al 2014; n = 174. Mean age: 36.5 + 17 years. Mean time post injury: 69.4 + 51.0 days)

  • The DOCS-25 has excellent construct validity. The hierarchical ordering of the items makes clinical sense and all 25 items fit the measurement model. The principal components analysis produced an eigenvalue of 3.2 and the percent of unexplained variance in the first contrast was 8.5%. While the eigenvalue is above the expected threshold of 2.0, further analysis of the disattenuated correlations between the item clusters (r=.97-.99) indicated the items represent the same construct. No differential item functioning was found.

 

Content Validity

The DOCS has acceptable content validity but only for differentiating persons in MCS from those in VS based on Aspen Workgroup criteria, the ability to detect emergence from MCS has not been studied.

Responsiveness

Brain Injury

DOCS-25: (Mallinson et al. 2016; n = 92. Mean age: 36.5 +/- 17 years. Time post injury: <90 days = 129, 91-180 days = 39, >180 days =4)

  • Moderate Change: Effect Size for all participants (n=92) = 0.45
  • Large Change: Effect Size for non-improvers (n=35) = 0.58
  • Moderate Change: Effect Size for improvers (n=57) = 0.45
  • Moderate Change: Standardized Response Mean for all participants (n=92) = 0.43
  • Large Change: Standardized Response Mean for non-improvers (n=35) = 1.3
  • Large Change: Standardized Response Mean for improvers (n=57) = 1.3

Bibliography

Kelly, J. P., Hurder, A. G., et al. (2005). "A measure of neurobehavioral functioning after coma. Part I: Theory, reliability, and validity of the Disorders of Consciousness Scale." Journal of Rehabilitation Research & Development 42(1): 1-18. 

Mallinson, T., Pape, T. L., & Guernon, A. (2016). Responsiveness, minimal detectable change, and minimally clinically important differences for the disorders of consciousness scale. Journal of Head Trauma Rehabilitation, 31(4): E43-51.

Pape, T. L. B., Heinemann, A. W., Kelly, J. P., Hurder, A. G., & Lundgren, S. (2005). A measure of neurobehavioral functioning after coma. Part I: Theory, reliability, and validity of the Disorders of Consciousness Scale. Journal of Rehabilitation Research & Development, 42(1): 1-18.

Pape, T., Senno, R., et al. (2005). "A measure of neurobehavioral functioning after coma. Part II: Clinical and scientific implementation." Journal of Rehabilitation Research and Development 42(1): 19-28.

Pape, T. L. B., Tang, C., et al. (2009). "Predictive Value of the Disorders of Consciousness Scale (DOCS)." PM&R 1(2): 152-161. 

Pape, T. L., Guernon, A., Lundgren, S., Patil, V., Herrold, A. A., Smith, B., . . . Hoffmann, M. (2013). Predicting levels of independence with expressing needs and ideas 1 year after severe brain injury. Rehabil Psychol, 58(3), 253-262

Pape, T. L., Mallinson, T., & Guernon, A. (2014). Psychometric properties of the disorders of consciousness scale. ACRM, 95(9): 1672-1684.

Seel, R. T., Sherer, M., et al. (2010). "Assessment scales for disorders of consciousness: evidence-based recommendations for clinical practice and research." Archives of physical medicine and rehabilitation 91(12): 1795-1813.