SCAN test-retest reliability for first- and third-grade children

Area of Science:

• Audiology
• Neuroscience
• Developmental Psychology

Background:

• The Screening test for Auditory Central Processing (SCAN) is a widely used tool for identifying potential central auditory processing disorder (CAPD) in children.
• Previous test-retest reliability data for SCAN, using a 6-month interval, suggested potential score unreliability.
• Despite concerns, SCAN has been utilized by both clinicians and researchers in assessing auditory processing in children.

Purpose of the Study:

• To investigate the test-retest reliability and stability of SCAN outcomes in children using a shorter retest interval.
• To examine score changes across SCAN subtests (filtered words, auditory figure ground, competing words) and composite scores.
• To determine the most reliable SCAN measure for clinical decision-making.

Main Methods:

• The study involved 25 first-grade and 22 third-grade children (ages 6-9) with normal hearing.
• Participants completed the SCAN test twice with a 6- to 7-week interval, keeping time of day and examiner constant.
• Analysis of variance (ANOVA) was used to compare scores from the initial test and retest.

Main Results:

• Significant improvements were observed in raw and standard scores for filtered words (FW), competing words (CW), and the composite (COMP) score from test to retest.
• The auditory figure ground (AFG) subtest was the only measure showing no significant test-retest difference.
• Test-retest correlations were moderately strong for CW and COMP scores (0.70 ≤ r ≤ 0.78).

Conclusions:

• The SCAN test's scores, particularly for FW, CW, and COMP, may improve with repeated administration, indicating potential learning effects or practice.
• The AFG subtest demonstrated greater stability compared to other SCAN measures.
• Clinicians are advised to rely solely on the COMP score for recommendations and acknowledge that a second administration might better reflect a child's optimal performance, though norms for second scores are lacking.