Preliminary Testing of the English Version of the Adolescent Screener for Intelligence and Learning Disabilities (SCIL) Among Adolescents in Nigeria

Background

There are few screening tools for intellectual disabilities that have been developed and used within Africa. This study aimed to examine the psychometric properties of the English version of the adolescent Screener for Intelligence and Learning Disabilities (SCIL) when used with Nigerian adolescents and young people.

Method

Two hundred nine adolescents and young people (aged 11–26 years) completed the SCIL and took part in an assessment of their level of general intellectual functioning and adaptive behaviour. Initially, principal components analysis was used to determine whether SCIL items should be retained or removed. Discriminative and convergent validity were then examined, along with the sensitivity, specificity, positive predictive (PPV) and negative predictive (NPV) values, using adjusted and nonadjusted diagnostic criteria for intellectual disability. The diagnostic criteria were adjusted because Western intelligence tests were not developed for use within Africa, and their use without adjustment remains contentious.

Results

All SCIL items were retained. The SCIL had good internal consistency, discriminative and convergent validity. Using adjusted diagnostic criteria, a SCIL cutoff score of 10 revealed sensitivity = 0.66, specificity = 1, PPV = 1 and NPV = 0.83 for identifying those with an intellectual disability. AUC was 0.91. Unadjusted diagnostic criteria and the original SCIL cutoff score of 15, revealed sensitivity = 0.67, specificity = 0.98, PPV = 0.96 and NPV = 0.82 with an AUC of 0.96.

Conclusions

The SCIL has good psychometric properties when used with Nigerian adolescents. Further factor analytic work is needed.