New chart to evaluate weight faltering.

A new chart was designed to aid accurate identification of weight faltering and failure to thrive. It provides guidance on the lower limits of expected weight gain for children, whatever their initial centile position. The chart's theoretical basis, the process of its construction, and its evaluation are described in this paper. Evaluation was by a self completion questionnaire, where respondents answered questions about a range of standardised growth patterns, plotted on old and new charts. Forty five health visitors, 28 general practitioner principals and registrars, and nine community paediatricians provided 328 chart ratings. These showed that the new format significantly increased the proportion of correctly rated charts (old: 45 (28%); new: 82 (51%)), with the greatest impact in severe cases. This suggests that the new chart improves the precision of judgments made about weight gain in infancy.