Outcome Measures for Traumatic Brain Injury

Dhaval ShuklaDepartment of Neurosurgery

NIMHANS

Disability Continuum Impairment

Activity Limitation

Participation Restriction

Evolution of Outcome Scales

Useful

Worthwhile

Mental restitution

Fully active

Persistent dementia

Able to participate

TBI

Evolution of Outcome Scales

• Glasgow Outcome Scale (GOS) was proposed in 1975 to assess the outcome of comatose patients after TBI

• The poor precision of GOS was realized and various outcome scales have been proposed since 1981 to assess disability following TBI

Properties of an outcome scale

Validity

PrecisionReliability

Validity

• Face validity– Is this instrument measuring what it purports to measure?

• Predictive validity– Can this instrument predict a future state or event?

• Discriminative validity– Can this instrument differentiate in scale scores between two

groups?• Construct validity

– Can this instrument measure relationships between the data of a (highly abstract) construct and data for other constructs?

• Ecological validity– Is the assessment data relevant to real life situations?

Validity

• Practically an outcome measure should not require much expertise to administer, technical simple, can be understood by participant, easy to scoring, and should not be time consuming

• An effective outcome measures should be feasible in following settings: population with a varied demographic profile, broad range of injury severity, varying time intervals, and by proxies, telephone, or mail

Reliability

• How reproducible is this measurement?• Inter-rater reliability (IRR)• Test Retest (TRT) reliability• Kappa coefficient.

– 1.0 – most reliable– > 0.9 – for decision making– 0.7 – 0.8 – for research

Precision

• Detect this change over time• Detect differences at the whole range of

possible outcomes (best, intermediate, or worst)

• Floor effect– Lowest measurable level is higher

• Ceiling effect– Highest measurable level is lower

Administering an Outcome Measure

• Review actual content, syllabus, scoring, and instructions required for administration

• Observing and/or evaluating patient condition• Structured interview with patient or close care

taker• Best judgment• Only preinjury status and current status

should be considered

Administering an Outcome Measure

• Current outcome should not be compared with the worst condition of the patient after injury

• Disability must be a result of mental or physical impairment due to TBI

• Other factors like systemic injuries, medical co-morbidities; non willingness to go back to work, etc. should be excluded

Choosing an Outcome Measure

• Impairment– Glasgow Coma Scale (GCS)– Neurological Outcome Scale for TBI (NOS-TBI)

• Activity Limitation– Functional Independence Measure (FIM)

• Participation Restriction– Community Integration Questionnaire (CIQ)

• Global – Disability Rating Scale (DRS)– Glasgow Outcome Scale (GOS)– Quality of Life after Brain Injury (QOLIBRI)

Impairment Assessment

• Glasgow Coma Scale (GCS)• 3 (worst) to 15 (best)• Useful to assess result of intervention in acute

stage

• Neurological Outcome Scale for TBI (NOS-TBI)• Structured, quantified neurological examination• Similar to NIHSS for stroke• Useful for evaluation at discharge

Activity Limitation Assessment

Functional Independence Measure (FIM)• Most useful for assessment of progress during

inpatient rehabilitation• 18-item, seven level ordinal scale• Ratings based on observed performanceFunctional Assessment Measure (FAM) consists of

12 additional items on cognitive, behavioral, and communication tasks

• Time required to administer FIM+FAM ~ 35 min.

FIM + FAM Properties

• FAM more valid for TBI than FIM• The Kappa score for the FAM is 0.85• FAM does not contribute beyond FIM in

predicting length of inpatient stay• FAM cognitive scores have better prediction of

return to work• FAM has increased sensitivity beyond FIM • FAM at rehabilitation discharge has less "ceiling

effect" than the FIM

Participation Restriction Assessment

Returning to the mainstream of family and community life, by persons with impairments and disabilities due to injury

Craig Handicap Assessment and Reporting Technique (CHART)

• Not means primarily for TBI

Community Integration Questionnaire (CIQ)

Community Integration Questionnaire (CIQ)

Social Integration (S)

Productive Activities (P)

Home Integration (H)

CIQ - Properties

• Brevity: Time required 15 minutes• Suitability for use in an in-person or telephone

interview• Conducted with the person with TBI or with

proxy• Ability to detect changes to a wide variety of

living situations• No formal training is required• CIQ -2

Global Outcome Measures

FSE

Rancho LCFS

QOLIBRI

NFIDRS

GOSE

Glasgow Outcome Scale (GOS)• Jennett and Bond 1975

– 5 point GOS

• Jennett et al. 1981– 8 point GOS Extended

• Wilson et al. 1998– Structured interview for the GOS/GOSE

• Wilson et al. 2002– Postal Questionnaires – based on the structured interview

• Pettigrew et al. 2003– Telephone Administration – based on the structured interview

• Lu J et al. 2010– Method for reducing misclassification – 2 tier process: GOS followed by GOSE– Central Monitoring

Glasgow Outcome Scale (GOS)

GOSGOS

FavorableFavorable UnfavorableUnfavorable

Good

Recovery

Good

Recovery

Upper

Lower

Upper

Lower

Moderate

Disability

Moderate

Disability

Severe

Disability

Severe

Disability

Vegetative

State

Vegetative

State

DeathDeath

Upper

Lower

Upper

Lower

Upper

Lower

Upper

Lower

Vegetative State

• Unconscious and unaware of their

surroundings

• Continue to have a sleep/wake cycle

• Periods of alertness

Severe disability (SD)

• Dependant on activities of daily living (ADL)

• Require actual assistance or reminder for ADL

• Upper level of SD

– Can be left alone for >8 hours

Moderate Disability (MD)

• Independent for ADL but dependant on

– Work or study

– Social and leisure activities

– Family and friendship

• Upper level of MD

– Can work in sheltered environment

Good Recovery (GR)

• None of the disabilities

• Return to normal life

• Post concussion syndrome

• Lower level of GR

– Bothersome symptoms

GOS - Properties

• Very good IRR and TRT• Validated for use through mail and telephone• GOS-E scores are associated with

neuropsychological test findings• Disproportionate weight of the physical (in

comparison to the cognitive and emotional) deficits for favorable outcome

Disability Rating Scale (DRS)Disability Rating Scale (DRS)• Most versatile outcome measure• Coma to community• Overcome the poor precision of GOS• Address all 3WHO categories:

– Impairment, disability, and handicap

DRS - Content

• Impairment– Modification of GCS

• Disability– Cognitive ability for Feeding– Cognitive ability for Toileting– Cognitive ability for Grooming

• Handicap– Level of Functioning– Employability

DRS -Properties

• Brevity (30 seconds to 15 minutes)• Reliability and validity tested• Can be administered over the phone• “Difficult” to rate

– Expertise required– Content difficulty

• Not sensitive to mild injuries• Not meant to measure change over short periods

of time

DRS – Relation with GOS

Neurobehavioral Functioning Inventory (NFI)

Aggression

Somatic

Depression

Memory/Attention

Critical Items

Communication

Motor

NFI - Properties

• Is a QOL measure• Identifies areas of least and greatest concern• Helpful in

– Characterizing the long-term sequelae of injury– Treatment planning– Compensatory strategy development

• Can be completed in 10-15 minutes

NFI – Relation with GOS

Neuropsychological Assessment

• Cognitive deficits are often overlooked in assessing outcome

• Disagreement among psychologists on an optimum test battery

• Test battery is often long or complicated– < 10 % of severe disability patients complete the

battery of tests– ~ 70 % of moderate disability and good recovery

patients complete the battery of tests

NIMHANS Neuropsychology Test Battery

• Behavioural Observation– Alertness, Attention, Arousability, Rapport, – Motivation, Co-operation, Comprehension

• Motor Speed– Finger Tapping

• Attention– Color Trails– Digit Vigilance

• Category Fluency– Animals Name

• Spatial Working Memory– Spatial Span

• Planning– Tower of London

NIMHANS Neuropsychology Test Battery

• Concept Formation and Set Shifting– Wisconsin Card Scoring

• Response Inhibition– Stroop

• Verbal Comprehension– Token

• Verbal Learning and Memory– Rey’s Auditory Verbal Learning

• Visual Learning and Memory– Rey’s Complex Figure

• Visuoconstruction Ability– Rey’s Complex Figure

• Parietal Lobe Signs– Apraxia, Aphasia, Body schema disturbance, Route finding, Agnosia

Time taken ~ 4 hoursRequirements•Trained neuropsychologist•Neuropsychology Lab

American Brain Injury Consortium (ABIC)

Test Area Addressed

Rey Complex Figure Visuoconstruction & memory

Controlled Oral Word Association Oral fluency

Symbol Digit Modalities (oral) Sustained attention

Grooved Pegboard Fine motor dexterity

Neurobehavioral Functioning

Inventory

Behavior/QOL

Composite Neuropsychological Score (CNPS)

• CNPS is average all of the percentile scores of the individual tests of the ABIC battery

• With appropriate training, this battery can be administered by nurses or other trained medical personnel

• Time ~ 30 minutes• Completion Rate

– > 60 % for full completion– ~ 20 % for partial completion

CNPS – Relation with GOS

Quality of Life after TBI(QOLIBRI)

Part 1 (Life satisfaction)– Overall satisfaction (6 items)– Cognition (7)– Emotion & self-perception (8)– ADLs (activities of daily living) & autonomy (8)– Social (6)Part 2 (Bothered by)– Negative feelings (5)– Restrictions & problems (4)– Physical condition (4)– An overall ‘bothered’ item

QOLIBRI Relation with GOSE

QOLIBRI – Properties

• Reliability – Satisfaction scales = excellent– Bothered scale = a work in progress– ICC Test-retest = good

• Scales unidimensionality– Satisfaction scales = excellent– Bothered scales = a work in progress

• Construct validity tests with other scales– Moderate correlations as expected

• Sensitivity tests (GOSE)– Satisfaction scales = excellent

Milestone Assessment

MonthsDays Weeks Years

GCSNOS-TBI

DRS

FIM+FAM

GOSE

QOLIBRI

Conclusion

• Survivors of TBI have complex variety of deficits leading to various problems in daily life affecting almost every sphere of life

• Outcome assessments vary in scope and mode of measurement

• What one wants to measure• Multimodal assessments are often necessary• GOSE remains the most widely used and accepted

instrument for TBI and in combination with neuropsychological tests is considered a near complete instrument for assessment of outcome after TBI