Computerized Symbol Digit Modalities Test in a Swiss Pediatric Cohort Part 1: Validation

Céline Hochstrasser; Sarah Rieder; Ursina Jufer-Riedi; Marie-Noëlle Klein; Anthony Feinstein; Brenda L Banwell; Michelle Steiner; Li Mei Cao; Karen Lidzba; Sandra Bigi

doi:10.3389/fpsyg.2021.631536

Computerized Symbol Digit Modalities Test in a Swiss Pediatric Cohort Part 1: Validation

Front Psychol. 2021 Apr 22:12:631536. doi: 10.3389/fpsyg.2021.631536. eCollection 2021.

Authors

Affiliations

¹ Division of Child Neurology, Department of Pediatrics, University Children's Hospital Bern, University of Bern, Bern, Switzerland.
² Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
³ The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
⁴ Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
⁵ Department of Neurology, University Hospital Bern, University of Bern, Bern, Switzerland.

Abstract

Objective: The objective of this study was to validate the computerized Symbol Digit Modalities Test (c-SDMT) in a Swiss pediatric cohort, in comparing the Swiss sample to the Canadian norms. Secondly, we evaluated sex effects, age-effects, and test-retest reliability of the c-SDMT in comparison to values obtained for the paper and pencil version of the Symbol Digit Modalities Test (SDMT).

Methods: This longitudinal observational study was conducted in a single-center setting at the University Children's Hospital of Bern. Our cohort consisted of 86 children (45 male and 41 female) aged from 8 to 16 years. The cohort included both healthy participants (n = 38) and patients (n = 48) hospitalized for a non-neurological disease. Forty eight participants were assessed during two testing sessions with the SDMT and the c-SDMT.

Results: Test-retest reliability was high in both tests (SDMT: ICC = 0.89, c-SDMT: ICC = 0.90). A reliable change index was calculated for the SDMT (RCIp = -3.18, 14.01) and the c-SDMT (RCIp = -5.45, 1.46) corrected for practice effects. While a significant age effect on information processing speed was observed, no such effect was found for sex. When data on the c-SDMT performance of the Swiss cohort was compared with that from a Canadian cohort, no significant difference was found for the mean time per trial in any age group. Norm values for age groups between 8 and 16 years in the Swiss cohort were established.

Conclusion: Norms for the c-SDMT between the Swiss and the Canadian cohort were comparable. The c-SDMT is a valid alternative to the SDMT. It is a feasible and easy to administer bedside tool due to high reliability and the lack of motor demands.

Keywords: SDMT; age-effect; c-SDMT; information processing speed; norms; practice effects; sex-effect; test-retest reliability.