Question
Is the SCAN 3 a screening or diagnostic test?
Answer
I received the inquiry asking whether SCAN:3 (the versions for both children and Adolescents/Adults) is a screening or diagnostic test. The short answer is that it is both, since SCAN:3 contains three screening measures that can be used to determine if the entire battery should be administered. If a person fails the screening test, or if there is a referral for diagnostic testing, then the audiologist can proceed with the diagnostic portion of the test.
The screening measures include a gap detection test, an auditory figure ground test at +8dB S/N ratio, and a free recall dichotic word test. The criterion referenced norms provide cut-off scores for pass or fail of the screening measures. The diagnostic tests include the same four tests used previously in the SCAN-C and SCAN-A tests in developing the composite score including filtered words, auditory figure ground, dichotic words under directed ear listening conditions, and competing sentences. There are optional tests available to investigate responses to time-compressed speech, and auditory-figure ground abilities at other speech to noise ratios.
The SCAN:3 diagnostic tests include standard scores with percentile ranks and confidence intervals that are so important in the interpretation of test findings. The 9 tests of the SCAN:3 test batteries include all of the behavioral measures recommended in the recent Guidelines for the Diagnosis, Treatment, and Management of children and adults with central auditory processing disorder published in 2010 by the American Academy of Audiology. Further to the point, most audiologists recognize that both SCAN-C and SCAN-A were diagnostic procedures that included four tests validated in previous studies of patients with confirmed central auditory lesions. Only the original SCAN test published in the 1980s was considered a screening measure.