Development of a nutritional risk screening tool for preterm children in outpatient settings during a complementary feeding period: a pilot study

BACKGROUND: A complementary feeding (CF) period is necessary for nutritional and developmental reasons. Preterm children encounter more feeding problems than their term counterparts in the CF period. The goal of this study was to develop a nutritional risk screening tool specific to preterm children (the NRSP) in outpatient settings in the CF period, with the expectation of providing a standardised process to determine feeding problems and subsequently offering targeted nutritional advice. METHODS: This study was a 2-phase study consisting of the development and evaluation phases. In the development phase, the items of the NRSP were initially developed based on references and the Delphi expert consultation method. Second, 329 preterm individuals with corrected ages from 5 to 36 months were enrolled. The participating preterm children were interviewed with the NRSP and anthropometric measurements, and underwent intellectual developmental tests and biochemistry detection (haemoglobin, red blood cell count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, serum iron, vitamin D). Third, preterm children’s anthropometric parameters were remeasured 1 month (for infants whose corrected age was 5–11 months) or 3 months (for children whose corrected age was 12–36 months) after the interview. Data in the development phase were analysed via univariate and binary logistic regression analysis sequentially to assign scores for items of the NRSP and to generate the models to predict underweight, stunting, and microcephaly of the NRSP. In the evaluation phase, another 605 preterm individuals were recruited to undergo the interview, anthropometric measurements, intellectual developmental tests, and biochemistry detection as in the development phase. Interrater reliability, test-retest reliability, area under the curve (AUC), accuracy, sensitivity, specificity, the positive/negative predictive value (P/NPV), the positive/negative likelihood ratio (LR+/−), and the correlation coefficient by Spearman’s correlation analysis (r(s)) were used to assess the reliability and validity of the NRSP. Finally, anthropometric parameters, biochemistry levels, and intellectual development quotients (DQs) from the development and evaluation phases between the high- and low-risk groups classified by the NRSP were compared using a t-test. RESULTS: The κ coefficients of the interrater and test-retest reliability of the NRSP were all above 0.600, which meant that the reliability of the NRSP was moderate to substantial. The NRSP exhibited relatively higher efficiency in predicting underweight and stunting, with AUCs, accuracies, specificities, and NPVs near to or greater than 0.900, sensitivities above 0.600, PPVs above 0.400, LR + s near to or greater than 10, and r(s)s above 0.400. On the other hand, the NRSP manifested a weaker ability in predicting microcephaly, with most of the values of validity indicators lower than those of underweight and stunting prediction. Z scores of body weight, body length and head circumference, as well as DQs, were all higher in the low-risk groups than in the high-risk groups. There were no significant differences with respect to biochemistry levels between the high- and low-risk groups. CONCLUSION: The NRSP shows moderate to substantial reliability and validity in predicting underweight, stunting, and microcephaly. Health care staff should shed light on improving the feeding practices of preterm children with high nutritional risk classified by the NRSP to facilitate their physical growth and intellectual development. More research is expected to promote the NRSP models. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-022-03774-5.