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Bridging the Gap: Traditional Assessments vs. Integrated Measures of Function Kathleen Baines, MS, CCC-SLP and Heidi McMartin, MS, CCC-SLP

Chelsea Community Hospital, Chelsea, Michigan

ALFA SUBTESTS: Addressing and Envelope & Solving Daily Math Problems

PRE- AND POST-TREATMENT SAMPLE ENVELOPES

TABLE 2. PRE-, POST-TREATMENT CHANGE IN ALFA SCORES

RELATIVE FUNCTIONAL GAIN FOR EACH ALFA SUBTEST

REFERENCES

Traditional measures of cognitive-communicative function assess language and cogni-tive modalities individually, e.g., word-finding, auditory comprehension, working memory. Clinicians are then obliged to extrapolate performance on functional tasks from individual measures. Rating scales can be subjective and suffer from rater bias (1,2). Neuroimaging studies of language, spatial perception and executive functions suggest that various cognitive tasks utilize different “pools” of cognitive resources. These form distributed cortical networks that support higher-level cognitive function (3,4). We assume that functional tasks utilize a broader distribution of cognitive resources than activities within isolated modalities. Therefore, behavioral measures of cognitive-communicative function should be taken in the context of familiar, functional tasks that engage language and cognition concurrently.

BRIDGING THE GAP

Reliable, quantifiable functional tasks can be used to assess many aspects of language and cognition (5). The Assessment of Language-Related Functional Activities (ALFA) (6) was developed to provide for the quick, objective measurement of language-related functional activities such as telling time, counting money, addressing an envelope, or daily problem-solving without having to extrapolate client performance to a real-life setting. This often reduces the need for lengthy cognitive testing. Language and cognitive modalities such as auditory comprehension, sentence-level reading, dual-tasking, processing speed and working memory are observed directly in the context of these functional activities, thus bridging the gap between isolated measures and functional tasks.

OBJECTIVES

To answer the questions:• Does the ALFA measure statistically significant change in the performance of neurologically impaired subjects?

• Are ALFA initial scores predictive of discharge disposition?

DESIGN

A prospective cohort study of pre- and post-treatment performance on the Assessment of Language-Related Functional Activities was conducted. Test subjects consisted of 464 consecutive admissions to the rehabilitation unit of a small community hospital. Subjects were sorted into four diagnostic categories: first incidence of left hemisphere stroke; first incidence of right hemisphere stroke; bilateral stroke, or new onset of stroke in persons with a history of previous stroke; and an “other” category which included subjects with traumatic brain injury or degenerative neurological disorders (e.g. Parkinson’s Disease, MS, brain tumor) with or without concurrent diagnosis of CVA. Cases with a history of psychological disorder, dementia, or ETOH abuse were excluded. The first four subtests of the ALFA were administered prior to and following treatment: ‘Telling Time’, ‘Counting Money’, ‘Addressing an Envelope’, and ‘Solving Daily Math Problems’. Performance on each subtest was scored on a scale of 1 (worst) to 10 (best). Cases with initial scores of 9 or 10 on any of the ALFA subtests were excluded from the data analysis to avoid a ceiling effect (Table 1). We calculated the ratio of pre- to post-treatment absolute functional gain (AFG) to potential gain (Relative Functional Gain, RFG) for each subtest*. Mean AFG, mean RFG, and 95% confidence intervals were examined. Logistic regression was used to study the relationship between discharge disposition and ALFA initial scores, controlling for diagnosis, age and the number of speech therapy days.

*Relative Functional Gain (RFG) is the ratio of absolute gain (actual change in score from pre- to post- treatment) to potential gain (the highest gain possible post-treatment). For example, if initial score is 2, and discharge score is 6, absolute gain is 4 (as 6 – 2 = 4). Potential gain at post-testing is 8 (as 10 – 2 = 8). Relative Functional Gain is the ratio of the absolute gain divided by the potential post-treatment gain which in this caseis .5 (as 4/8 = .5).

OUTCOMES

Assessment of Language-Related Functional Activities:• Telling Time subtest• Counting Money subtest• Addressing an Envelope subtest• Solving Daily Math Problems subtest

Discharge disposition: home vs. other location

RESULTS

OPTIONALLOGO HERE ASHA 2009

ALFA SUBTESTS: Telling Time & Counting Money

Table 1. All cases with an initial score of 9 or 10 out of a possible 10 points were tallied and then excluded from the data set to avoid a ceiling effect. We examined the impact of the ceiling effect on each of the four ALFA subtests. The graph above illustrates the results. Over twice as many cases were excluded due to high initial score for the ‘Telling Time’ subtest compared to the other three ALFA subtests for each diagnostic category. This suggests that the skills involved in telling time are different from the other three functional tasks and are more preserved across these diagnostic categories.

TABLE 3. ANALYSIS OF VARIANCE: AFG x DISCHARGE HOME

ALFA SUBTESTAbsolute Gain Relative Functional Gain

Mean Change

95% Confidence Interval

Mean Change

95% ConfidenceInterval

Telling Time 1.66 (1.32,2.00) 0.35 (0.28,0.42)

Counting Money 1.81 (1.52,2.11) 0.31 (0.25,0.37)

Addressing an Envelope

2.48 (2.13,2.77) 0.40 (0.36,0.45)

Solving Daily Math Problems

1.57 (1.29,1.85) 0.27 (0.21,0.33)

CONCLUSIONS

The ALFA is a clinically useful outcome measure of cognitive-communicative function. The absolute functional gain in post-treatment scores has been shown to be statistically significant for all four ALFA subtests. Another positive finding is that subjects with bilateral strokes or a history of more than one stroke make progress on the selected ALFA subtests. Based on a logistic regression model, the ‘Counting Money’ subtest has value as a predictor of the probability of discharge home, although further study is needed. Increasing the number of cases studied may add to the predictive value of the ALFA.

Relative Functional Gain (RFG) allows us to look at change in functional performance relative to the maximum score on a specific measure. The mean RFG would lend itself to the study of treatment efficacy for a specific intervention, i.e. practice adding coins to improve counting money skills, because it compares gain to potential gain.

There is missing data across all diagnostic categories, which leads us to examine the factors that influence the ability to collect pre- and post-treatment scores on this inpatient population. Potential factors include a change in medical status, transfer off the unit or early discharge, the need to prioritize treatment tasks, and other concurrentdeficits including dysphagia, motor speech and language dysfunction, and cognitive impairments.

PERCENT OF CASES EXCLUDED DUE TO HIGH INITIAL SCORESBACKGROUND

ALFA SUBTEST RELATIONSHIP TO DISCHARGE HOME

TELLING TIME Not Significant (p = 0.96)

COUNTING MONEY Significant (p = 0.05)

ADDRESSING AN ENVELOPE Not Significant (p = 0.51)

SOLVING DAILY MATH PROBLEMS Not Significant (p = 0.81)

88 year-old-male with history of left pontine CVA and left parietal temporal ischemic CVA’s

75-year-old female status post right hemisphere CVA with left homonymous hemianopia and left neglect

71-year-old female status post large infarct in right parietal lobe extending into insular cortex, as well as small chronic infarcts in the left posterior parietal lobe. Patient

complains letters run together.

78-year-old male 9 days post left CVA with history of previous left CVA, with complaints of visual blurring

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(2) Plant, M. A., Richards, J. S., Hansen, N. K. (1998). Potential for Bias of Data from Functional Status Measures, Arch Phys Med Rehab, 79(1), 104-106.

(3) Just, M. A., Carpenter, P.A., Miyake, A. (2003). Neuroindices of Cognitive Workload: Neuroimaging, Pupillometric and Event-Related Potential Studies of Brain Work,Theoretical Issues in Ergonomics Science, 4(1-2), 56-88.

(4) Kelly, C., Foxe, J. J., Garavan, H. (2006). Patterns of Normal Human Brain Plasticity After Practice and Their Implications for Neurorehabilitation, Arch Phys Med Rehab, 87(12), 20-29.

(5) Gillen, G. (2009) Cognitive and Perceptual Rehabilitation: Optimizing Function. Maryland Heights, MO: Mosby Elsevier.(6) Baines, K. A., Martin, A. W., McMartin Heeringa, H. (1999). Assessment of Language-

Related Functional Activities. Austin, TX: PRO-ED.

95% confidence intervals for mean Absolute Functional Gain (AFG) for each ALFA subtest demonstrated a statistically significant positive change between pre-treatment and post-treatment scores (Table 2). In the logistic regression model of discharge to home (Table 3), after controlling for patient age, diagnostic category, and number of speech therapy days, the AFG for the ALFA ‘Counting Money’ subtest is significantly and positively (p = 0.05) associated with the probability that a client will be discharged home. This provides external validation of the ‘Counting Money’ subtest as a measure of executive function and thelevel of recovery necessary for a discharge to home.