Validation of a culturally modified short form of the McCarthy Scales of Children’s Abilities in 6 to 8 year old Zimbabwean school children: a cross section study

BACKGROUND: The burden of cognitive impairment among school children from developing communities is under reported due to lack of culturally appropriate screening tools. The objective of this study was to validate a culturally modified short form of the McCarthy Scales of Children Abilities (MSCA) in school children aged 6–8 years from varied backgrounds. METHODS: One hundred and one children aged 6–8 years attending mainstream classes were enrolled cross-sectionally from three schools: one rural and two urban. Two assessments were conducted on each child and the Short form MSCA was compared to an independent assessment by the educational psychologist. RESULTS: When comparing the results of the MSCA to local standard at -2SD, -1.5 SD and -1SD the sensitivity rates ranged from 17 to 50% with lower sensitivity at -2SD cut-off point. Specificity rates had less variation ranging from 95% to 100%. The number of children identified with cognitive impairment using -2SD, -1.5SD and -1SD below the mean for MSCA as a cut-off point were 3(3%), 7(7%) and 13(13%) respectively while the psychologist identified 18 (18%). The overall mean score on MSCA was 103 (SD 15). The rural children tended to score significantly lower marks compared to their peers from urban areas, mean (SD) 98(15) and 107(15) respectively, p=0.006. There was no difference in the mean (SD) scores between boys and girls, 103(17) and 103(15) respectively, p=0.995. CONCLUSION: The culturally modified short form MSCA showed high specificity but low sensitivity. Prevalence of cognitive impairment among 6 to 8 year children was 3%. This figure is high when compared to developed communities.