Hospitalization as a measure of morbidity among very low birth weight infants with chronic lung disease

Objective: To examine the spectrum of hospitalization and rehospitalization among very low birth weight (VLBW, <1500 gm) infants with severe chronic lung disease during the first 2 years of life. Population: All 124 VLBW infants admitted to our center from October 1988 to September 1990 who were oxygen and ventilator dependent at 21 days of age. One hundred infants survived to discharge, of whom two subsequently died. The 98 surviving infants are the subject of this report. Methods: The duration of the neonatal stay, the use of a long-term care facility, and rehospitalizations were recorded to a postnatal age of 24 months. The duration of these hospitalizations and the total duration of hospitalization during the first year of lite were correlated with demographic and perinatal risk factors and 20-month outcome. Results: The 98 infants spent a median of 125 days (range, 44 to 365) of their first year hospitalized; the neonatal stay accounted for 85% of this time. Forty-nine of the infants (50%) were rehospitalized in their first year (median stay, 14 days), and 36 (37%) were rehospitalized in their second year (median stay, 7 days). Long-term care facility stay and rehospitalizations accounted for 6% and 9% of the first- year hospitalizations, respectively. A median of 9 days (range, 1 to 365) of the second year of life were spent in hospital. The infants rehospitalized during their first year of life did not differ significantly from those not requiring rehospitalization with regard to maternal demographic descriptors, birth data, severity of chronic lung disease, or measures of 20-month outcome. Both duration at neonatal stay and total hospital stay during the first year were significantly associated with all measures of chronic lung disease severity and with 20-month neurodevelopmental outcome measures, whereas the duration of rehospitalization was associated only with duration of oxygen dependence. Conclusion: Among infants with severe chronic lung disease, the total duration of hospitalization during the first year of life provides a better index of morbidity than the number or duration of rehospitalizations alone.