SCAN-C: Screening or Diagnostic Tool

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The SCAN (before it was ever -C, or -A) was designed to screen auditory processing skills, specifically dichotic listening (by way of competing words and competing sentences tests) and auditory closure (by way of filtered words and auditory figure-ground tests). It's -1SD from the mean "pass-fail" criterion is, in general, the "cut-off" of choice for a screening instrument. It does a pretty good job of screening these skills. That it lacks a temporal screening task is an issue for some as temporal processing is such an important skill. Since its debut, some professionals have pointed to so-called over-referrals based on SCAN-C results, as if that's a bad thing. It's not. I, for one, would much rather have a client fail a screener and then "pass" the diagnostic battery than the other way around. That's the goal of screening - to cast a broad net for those at-risk for a disorder so that they may be directed to appropriate examiners for diagnostic testing. However, since its debut, a number of audiologists have chosen to use the SCAN-C or SCAN-A as part of their diagnostic battery. It is not good scientific methodology to use any tool designed for screening to diagnose as, typically, screening tests have not be validated on a population of listeners with known neurologic disorder, but instead rely simply on what's outside the "norm" to determine pass-fail. Remember, screeners identify those "at-risk" and diagnostic tests rule in/rule out the disorder and specify its nature. Tests designed to screen for CAPD should be used to screen for the disorder, not as a diagnostic tool. To do otherwise risks "diagnosing" a problem that may not exist, which wastes resources and disserves our clients.

Jeanane M. Ferre, PhD Audiologist, CCC-A. Fellow of American Speech-Language-Hearing Association Central Auditory Evaluation and Treatment Oak Park, IL.