Prediction of Length of Hospital Stay in Neonatal Units for Very Low Birth Weight Infants

Abstract

OBJECTIVE:

To develop models for estimating the length of hospital stay (LOS) of very low birth weight infants (VLBW), based on perinatal risk factors present during the first week of life and during the entire hospitalization period.

STUDY DESIGN:

The files of 155 VLBW were analyzed, and the influence of individual risk factors were initially evaluated by univariate analysis, using multiple-regression. Two mathematical models were built to estimate the LOS.

RESULTS:

The first model, using risk factors present during the first 3 days of life, is as follows: LOS = −0.074A + 22.06B + 22.85C − 16.78D − 2.07E + 10.51F + 203.12 (R² = 0.63). (The letters are added to show what each number represents: A: birth weight; B: occurrence of respiratory distress syndrome; C: endotracheal intubation during resuscitation; D: 1-minute Apgar score; E: gestational age; F: presence of complications during delivery.) The second model, using factors present during the entire hospitalization period, is: LOS = 0.61G + 29.19H + 24.68I + 14.21J + 23.56K + 9.54L + 7.41M + 20.43 (R² = 0.82). (G: age receiving nutritional support of ≥120 kcal/kg per day; H: occurrence of systemic candidiasis; I: birth weight < 1000 gm; J: presence of delivery complication; K: occurrence of bronchopulmonary dysplasia; L: birth weight ≥ 1000 gm and ≤ 1249 gm; M: occurrence of anemia).

CONCLUSION: Both models are applicable for estimating the hospitalization period, and the addition of variables present during the entire hospitalization period improved the accuracy of the model.