Early gross motor development: Agreement between the AIMS and the BSID-III.

The infants were full-term and considered low-risk for gross motor delay, so the findings may not apply to preterm infants or infants with known high-risk conditions. Only 112 toddlers were analysed at 18 months after six losses to follow-up, and 11 scored below average, so the accuracy estimates have wide confidence intervals. The 23rd percentile cut-off was derived from this same sample, so it may not apply directly to other populations. Differences in infant care practices, such as back carrying or tummy time duration, were not accounted for. The sample came from low-income urban and peri-urban communities in Cape Town and included mothers with psychiatric diagnoses plus a comparison group, so it may not represent other populations.

Funding was provided by the South African Medical Research Council through its Division of Research Capacity Development under the Bongani Mayosi National Health Scholars Programme from the South African National Treasury, and by the University of Tampere and the National Research Foundation of South Africa. The authors state the content is their sole responsibility and does not necessarily represent the official views of the funders.

Do not treat a positive AIMS screen at 6 months as proof of later gross motor delay. The 10th percentile cut-off had a positive predictive value of 60%, and the proposed 23rd percentile cut-off had a positive predictive value of 28%.