Diagnostic accuracy of the Molteno Adapted Scale for developmental delay in South African toddlers

Background: There is currently a great need in South Africa for culturally appropriate neurodevelopmental screening measures in order to facilitate early identification of neurodevelopmental problems in children. Neurodevelopmental screening has the potential to decrease the burden at health-care facilities as it is time, resource and cost effective. Aim: To assess the use of the Molteno Adapted Scale (MAS), a locally developed screening measure, to suggest an optimal cut-off score and investigate its accuracy in detecting developmental delays. Method: The MAS was assessed by evaluating three components: accuracy, efficacy and usefulness. For each of 136 participants, MAS scores were compared with dichotomised scores from the Griffiths Mental Development Scales (GMDS). Receiver operating characteristic (ROC) curves were generated to determine the accuracy of the MAS in identifying developmental delay defined by the GMDS. Sensitivity, specificity and predictive values were calculated for potential MAS cut-off scores. Results: The MAS had an excellent area under the ROC curve, indicating good test accuracy. A developmental quotient of 83 was identified as optimal for screening purposes, with acceptable sensitivity (71.4%) and specificity (90.7%) as well as predictive values (29.4% positive predictive value and 98.3% negative predictive value) for developmental delay on the GMDS. Conclusion: The present study provides preliminary evidence supporting the use of the MAS for screening.