OBJECTIVE: to assess the agreement between two trained psychologists who administered the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits in a cohort of children within the Northern Adriatic Cohort II (NAC II) longitudinal study, which aims to assess the impact of mercury exposure through food consumption of mothers in pregnancy on their children's neurodevelopment. DESIGN: a reliability study was carried out. Two trained psychologists administered the test, each one scoring the test independently, and serving as the primary examiner for half of the sample and as the observer for the other half. SETTING AND PARTICIPANTS: a sample of 53 children of 18 months of age was enrolled consecutively within the Italian NAC II, and tested using the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits. MAIN OUTCOME MEASURES: the cognitive, language, and motor scales of the BSID III were evaluated and the respective Intraclass Correlation Coefficients (ICC) were calculated. RESULTS: overall, the ICCs for the cognitive and language scales were very high (≥0.98), while the ICCs for the motor scales were slightly lower, ranging from 0.86 (gross motor, scaled) to 0.97 (fine motor, scaled), but still higher than 0.80, reported as the general acceptable benchmark for psychological testing. CONCLUSION: the interrater reliability of all BSID III scales for this sample of 18-month-old children is very high and assures comparable results between the two psychologists involved in the Italian NAC II study. The reasons are a common training, the joint evaluation of many children during the preliminary phase of the study, the discussion of inconsistent results, but also the "go no-go" nature of the items in BSID III.
OBJECTIVE: to assess the agreement between two trained psychologists who administered the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits in a cohort of children within the Northern Adriatic Cohort II (NAC II) longitudinal study, which aims to assess the impact of mercury exposure through food consumption of mothers in pregnancy on their children's neurodevelopment. DESIGN: a reliability study was carried out. Two trained psychologists administered the test, each one scoring the test independently, and serving as the primary examiner for half of the sample and as the observer for the other half. SETTING AND PARTICIPANTS: a sample of 53 children of 18 months of age was enrolled consecutively within the Italian NAC II, and tested using the Bayley Scale of Infant Development III (BSID III) to detect neurodevelopment deficits. MAIN OUTCOME MEASURES: the cognitive, language, and motor scales of the BSID III were evaluated and the respective Intraclass Correlation Coefficients (ICC) were calculated. RESULTS: overall, the ICCs for the cognitive and language scales were very high (≥0.98), while the ICCs for the motor scales were slightly lower, ranging from 0.86 (gross motor, scaled) to 0.97 (fine motor, scaled), but still higher than 0.80, reported as the general acceptable benchmark for psychological testing. CONCLUSION: the interrater reliability of all BSID III scales for this sample of 18-month-old children is very high and assures comparable results between the two psychologists involved in the Italian NAC II study. The reasons are a common training, the joint evaluation of many children during the preliminary phase of the study, the discussion of inconsistent results, but also the "go no-go" nature of the items in BSID III.