Reliability, validity and normative data of a quick repetition test for Italian children

A quick repetition test can be useful as a screening or preliminary investigation to select children who need to be assessed with a more specific articulation test. Schindler's repetition test lasts about 2 min and requires the repetition of a 30 words list, each word targeting a specific phoneme or cluster. The aims of the study are: to assess reliability of Schindler's repetition test; to establish normative data for speech development in Italian-speaking children; to analyse validity of this instrument.

Six-hundred-two Italian children, aged range between 3;0 and 10;8 years, were included in the study: 557 without clinical sign of speech impairment and 45 had a speech sound disorder. Reliability. One-hundred-five children were tested the same day by two examiners (inter-rater reliability); the administration of the repetition test to 45 children was audio-recorded (intra-rater reliability); 105 children underwent the repetition test twice, with a 2 weeks interval (test-retest reliability). Data were compared through Intraclass Correlation Coefficient (ICC). Normative data. Percentages of children without clinical sign of speech impairment in each age group who repeated correctly, omitted or produced distorted target phonemes of Schindler's repetition test were reported.

To assess the ability of the test to record improvement in mean values with age (construct validity), the proportion of correct repetitions obtained by children from different age groups were compared through logistic regression. The speech abilities of 45 children were also analysed through a more comprehensive articulation test (concurrent validity). Scores were compared through Bland-Altman plot.

Reliability. All ICC were superior to 0.9. Normative data. Despite language-specific pattern of acquisition emerged, data showed many similarities to data reported in international studies on speech sound development.

Logistic regression demonstrated a significant effect of age groups. Bland-Altman plot showed relatively narrow limits of agreement between Schindler's repetition and Rossi's articulation test.

Schindler's repetition test can be considered a reliable and valid instrument for preliminary assessment of speech abilities in Italian-speaking children aged from 3 to 6 years old. Application of Schindler's repetition test is recommended in clinical practice, as a screening test or as a first clinical assessment instrument.