Table 1.
Description of the cognitive and motor measures used in the study.
| PCA Components | Name of Test | Domain | Description of Measure | Absolute Scores (Min, Max) |
|---|---|---|---|---|
| Verbal and non-verbal IQ | Block design | Non-verbal IQ | The measure is adapted from the British Ability Scales-third edition [26]. The child is asked to copy and construct items with wooden blocks following a demonstration by the assessor. | 0, 16 |
| Picture vocabulary scale | Verbal IQ | The measure is adapted from the Kilifi Vocabulary Test [27]. The child is asked to point out and identify items from 24 black and white picture items familiar to them. | 0, 24 | |
| Executive function | Verbal fluency | Working memory | The measure is adapted from the Developmental NEuroPSYchological Assessment [28]. The child is asked to name items including foods and animals as fast as possible in a minute. | * |
| Picture search | Selective attention | The measure is adapted from the Sky Search in Tests of Everyday Attention for Children [29]. The child is presented with three A3 sheets each with a target picture on top and about 100 others at the bottom including copies of the target picture. The child is asked to locate as many copies of the target pictures as possible within 10 s. | ** | |
| Wisconsin card sort test | Cognitive flexibility | The measure is adapted from Berg’s card sort test [30]. The child is given four playing cards of different suits and a pack of 12 cards and asked to sort the cards by number (block 1) and suit (block 2). | 0, 12 | |
| Motor function | Coin box | Fine motor function | The measure is adapted from the Kilifi Developmental Inventory [31]. The child is asked to slot coins through a small opening on a coinbox within 20 s in two trials. | 0, 20 † |
| Balancing on one leg | Gross motor function | The measure is adapted from the Movement Assessment Battery for Children [32]. It entails timed attempts (two per leg) of balancing on one leg for one minute. | 0, 60 † |
PCA, principal components analysis; IQ, intelligence quotient; Min, minimum score; Max, maximum score. *One point is awarded for each correct name and a total score is calculated from the total correct names in a minute. **A total score is calculated from the number of target pictures identified within 10 s. † An average score is calculated after timed attempts of the tests. Block design and picture vocabulary tests loaded heavily on verbal and non-verbal IQ while verbal fluency, picture search and Wisconsin card sort tests loaded heavily on executive function. Coinbox and balancing on one leg tests loaded heavily on motor function. The resulting scores were centred on zero with higher scores representing better and lower scores worse development.