Behavior as a diagnostic aid in failure-to-thrive.

The presence of a defined set of behaviors was examined in 67 hospitalized infants, 3-24 months old; 17 with organic failure-to-thrive (OFTT), 17 with nonorganic failure-to-thrive (NOFTT), and 33 with no signs of failure-to-thrive. The usefulness of assessing these behaviors to distinguish nonorganic from organic failure-to-thrive infants was evaluated. The frequency of behaviors per infant as well as the intensity of behaviors was greater for NOFTT. The order of decreasing frequency of behaviors was similar in both OFTT and NOFTT infants. Four of the 7 most prevalent behaviors occurred significantly more frequently in NOFTT than OFTT infants. The presence of these behaviors does not rule in NOFTT or rule out OFTT. However, when a number of the behaviors are present, particularly if they occur in high intensity, and when no organic disease is found, a diagnosis of NOFTT is suggested. Response to appropriate treatment remains the most reliable confirmation of the diagnosis.