Abstract
Test Description
General Description
The Advanced Clinical Solutions (ACS) for the Wechsler Adult Intelligence Scale–Fourth Edition (WAIS-IV; Wechsler, 2008) and the Wechsler Memory Scale–Fourth Edition (WMS-IV; Wechsler, 2009) was published by Pearson in 2009. It is a clinical tool for extending the assessment of individuals’ cognitive functioning. Generally, the ACS provides supplemental information for the results of the WAIS-IV and WMS-IV; it includes six components that are relatively independent, namely, additional scores, effort measures, demographically adjusted norms, reliable change scores, test of premorbid functioning, and social cognition subtests. These new elements were specially designed for forensic evaluations, readministrations, and neuropsychological evaluations.
The age range for the ACS varies for different elements, but for most tests it is 16 to 90, as consistent with the WAIS-IV and WMS-IV. A technician or graduate assistant with appropriate graduate-level training can administer and score the tests under supervision, but as stressed in the Administration and Scoring Manual results should only be interpreted by professionals with extensive training in assessment. In addition, to use the ACS for assessing neuropsychological functioning, examiners must have adequate background in neuropsychological assessment.
Specific Description
Across different subtests in the ACS, the examinee receives either visual or verbal stimuli (either in audio recording or read by examiners) and responds either verbally or by arranging the materials given. As the components are relatively independent, each is described separately below.
Additional scores
The additional scores reported in the ACS are computed based on results of the WAIS-IV and WMS-IV and require no additional responses from the examinee. These include eight index scores, four sets of subtest scores (logical memory, verbal paired associates, designs, and visual reproduction), two sets of contrast scaled scores for the WMS-IV, and a cancellation subtest score for the WAIS-IV. As the WMS-IV has an adult battery (ages 16-69) and an older adult battery (ages 65-90), some additional scores are age specific.
Effort
Five effort scores can be obtained using the ACS, including the Word Choice subtest, which is unique to the ACS, plus four other scores embedded in the WAIS-IV Reliable Digit Span, WMS-IV Logical Memory II Recognition, WMS-IV Verbal Paired Associates II Recognition, and WMS-IV Visual Reproduction II Recognition. The Administration and Scoring Manual advises that a minimum of three out of these five scores must be obtained to judge whether the examinee is exhibiting suboptimal effort. The effort measures are only available for ages 16 to 69.
Demographically adjusted norms
In addition to the age norms provided by the WAIS-IV and WMS-IV, the ACS provides norms that further take into account examinees’ educational and other demographic characteristics. These norms include education-only adjusted T-scores and full demographic adjusted T-scores (which incorporate sex, race/ethnicity, and years of education). The adjusted norms may make interpretation more complicated, and thus the Administration and Scoring Manual advises to reserve their use for specific clinical questions.
Reliable change scores
When the WAIS-IV and WMS-IV are readministered to the same examinee at a second time, the ACS software can provide reliable change scores, which are adjusted scores based on a regression model controlling for practice effect, cognitive functioning, and age.
Premorbid functioning
The ACS provides information about whether examinees have suffered from decline of cognitive functioning after certain points through (a) the administration of the Test of Premorbid Functioning (TOPF), which is a revision of the Wechsler Test of Adult Reading, or (b) the consideration of demographic characteristics including education, occupation, religion, sex, race/ethnicity, and other factors such as perceived wealth and parent education, or (c) both the TOPF and demographics. The TOPF requires the examinee to pronounce words from a given word card that do not follow conventional grapheme-to-phoneme pronunciations. Through the ACS software interpreters can choose between (a) the TOPF only model, (b) the demographics only predictive model, and (c) the demographics with TOPF predictive model. Based on different predictive models, examiners can compare the predicted versus the actual WAIS-IV and WMS-IV composite scores to determine the degree of cognitive decline.
Social cognition
Social cognition is a new area not included in the WAIS-IV and WMS-IV. The Social Cognition subtests were developed to address the increasing need for assessment of processing of social information. The three subtests are Social Perception, Faces, and Names. Social Perception measures competency in social situations and requires examinees to label emotions from visual or auditory stimuli and includes three tasks: affect naming, prosody-face matching, and prosody-pair matching. The Face subtest measures content and spatial memory of faces, and includes Faces I (immediate recall) and Faces II (delayed recall) conditions. The Names subtest measures competency in recalling face-name associations and again has Names I (immediate recall) and Names II (delayed recall) conditions.
Scoring System
Scoring varies for different components of the ACS. In general, scoring can be done by hand with the assistance of score booklets or through the ACS scoring software. The ACS yields raw scores, scaled scores, equated scaled scores, contrast scaled scores, index scores, and standard scores. The ACS provides normative tables to interpret final scores that are sensitive to individual demographic differences.
Test Materials and Stimuli
Materials in the ACS include the Administration and Scoring Manual, ACS software, additional scores booklet, Word Choice and social cognition stimulus books, different test record forms, faces card, and memory grid. The Administration and Scoring Manual provides elaborate instructions for using materials and instruments, step-by-step scoring, and other details of different subtests. Tables provided in the Administration and Scoring Manual are well organized, which facilitate the tedious score conversion and complex demographic adjustment. The record forms are well structured and provide enough space to record and score responses. The ACS software also contains audio stimuli for the Social Perception subtest. The voice is clear, with moderate speed, and exhibits an appropriate level of emotion.
Technical Adequacy
Standardization
The ACS is an extension of the WAIS-IV and WMS-IV, so most of the subtests used the same normative samples for these two tests. For Social Cognition, representative samples were selected by stratified sampling, based on age, sex, race/ethnicity, and education level, which matched stratification of the U.S. Bureau of the Census in 2005. For the Faces and Names subtests, samples were relatively small and less stratified.
Reliability
A majority of WAIS-IV and WMS-IV additional scores showed moderate to high internal reliabilities across most age groups (0.80s to 0.90s). For the TOPF, both age groups and special groups had high reliabilities (0.96 and higher). Social Cognition had moderate to high (0.69 to 0.94) internal consistencies for age groups and even higher coefficients for special groups.
The scores for both tests of additional scores demonstrated a moderate to high degree (0.50 to 0.82) of test-retest reliability. The TOPF scores of age groups were also highly stable across time with test-retest reliability ranging from 0.89 to 0.95. For Social Perception scores, the only part of Social Cognition that had a retest, the SP Pairs showed high correlation between test administrations (0.83). The decision-consistency reliability of additional scores had high coefficients ranging from upper 0.80s to upper 0.90s. For Social Cognition, interscorer reliabilities of both objective and subjective subtests were higher than 98%.
Validity
Within the ACS, four subtests provided validity information: the Additional Scores, TOPF, Effort Measure, and Social Cognition. Most of the validity evidence on Additional Scores and TOPF was obtained from examinations of the subtests’ correlations with external tests designed to measure the same or similar constructs. Special group studies also provided evidence supporting the validity of these scores with special populations, such as older adults and individuals with different types of disorders.
Validity studies demonstrated that Additional Scores were highly correlated with WMS-IV scores and were valid to identify the varying natures of memory deficits in addition to overall memory problems. The validity of TOPF scores was supported by high correlations with tests designed to measure verbal functioning and sensitivity on Probable Dementia of the Alzheimer’s Type-Mild Severity (ALZ) and Traumatic Brain Injury (TBI) groups, which were consistent with the intention of these predictions. However, the prediction model would work best when a significant level of impairment was present.
One external validity measure and four embedded devices were developed to detect validity of the suboptimal effort measure in the ACS. The developers of the ACS suggested using the whole five measures to achieve the maximum effect, but a study conducted by Miller and colleagues (Miller et al., 2011) indicated that even using the Word Choice test alone would have a strong discriminating power.
For Social Cognition, which was developed specifically for the ACS, validity evidence was provided based on test content, response processes, and relationships with external variables. Throughout the construction of the test, processes associated with interpreting social interaction were adequately sampled, and information on response processes was collected to ensure that examinees engaged in the expected cognitive processes when responding to the tests. However, validity studies on the Social Perception, Faces, and Names subtests were conducted on different samples and special groups. Furthermore, a convenience sample was used, which might not represent the whole clinical population and influence the generalization of the test results. Finally, the special group samples were collected under various clinical situations and different diagnostic criteria and procedures might have been used for individuals within the same group. Therefore, clinicians are recommended to use the Social Cognition results with special caution if external diagnostic evidence from interviews and observations is not available.
Commentary and Recommendations
The ACS is specially designed to complement the WAIS-IV and the WMS-IV and serves different purposes including assessment of suboptimal effort, examination of social cognition, prediction of premorbid functioning, and adjustment for additional demographic information and multiple assessments. Thus, the ACS is a highly flexible clinical tool. The ACS has a number of strengths. First, most of the components of the ACS do not require separate assessment beyond the WAIS-IV and the WMS-IV, which saves demand on examinees. Second, instructions for converting scores from subtests of the WAIS-IV and WMS-IV are easy to follow. For scores based on more complicated statistical models, such as reliable change scores and demographic-adjusted norms, the ACS software greatly simplifies the work of examiners. Third, the inclusion of the social cognition component makes the WAIS-IV and WMS-IV more comprehensive. This is a response to the increase in neurological research findings and concern about how brain damage may impact one’s social life.
Nevertheless, several weaknesses of the ACS should also be mentioned. First, the introduction of demographically adjusted norms and premorbid functioning prediction models makes interpretation of results even more difficult. In addition, the efficacy of the TOPF is unclear, as stated in the Administration and Scoring Manual. To us, it seems insufficient to use only reading abilities and demographics to judge whether an examinee has suffered from decline in general cognitive functioning. In addition, the adequacy of the social cognition component still needs more evidence, given the low internal consistency and test-retest reliability of the Social Perception subtest and the small samples used in establishing its concurrent validity with special groups. Finally, the items in the Social Perception and Faces subtests arguably are culture specific and thus may not be suitable for people outside of the United States even if they understand English.
All in all, the ACS exposes the WAIS-IV and the WMS-IV to more options for interpretations in an efficient way. It would be beneficial if systematic guidelines are provided for when to use the ACS and which demographically adjusted norms or predictive model to use. It is also recommended that the Clinical and Interpretation Manual would include comparison with tests other than those in the Wechsler series, particularly for the social cognition component. More research on the validity and utility of the reliable change scores and test of premorbid functioning is highly encouraged.