Korean J Pediatr 2010;53(6):694-700 • DOI: 10.3345/kjp.2010.53.6.694 Table 3. Univariate Relationships Between Individual Neonatal Morbidity and Outcome at 18-24 Months of Corrected Age Neonatal morbidity BPD Brain injury ROP PNAC Present Absent Present Absent Present Absent Present Absent Poor outcome: death or neurosensory impairment* Components of poor outcome : Death and Individual impairments, No/Total (%) No/Total (%) 11/17 (64.7) 23/63 (36.5) 13/18 (72.2) 21/62 (33.9) 21/37 (56.8) 13/43 (30.2) 7/9 (77.8) 27/71 (38.0) OR (95% CI) 3.2 (1.0-9.8) 5.1 (1.6-16.2) 3.0 (1.2-7.6) 5.7 (1.1-29.5) P value 0.037 0.004 0.017 0.038 Death 5/17 (29.4) 1/63 (1.6) 1/18 (5.6) 5/62 (8.1) 4/37 (10.8) 2/43 (4.7) 5/ 9 (55.6) 1/71 (1.4) CP 1/12 (8.3) 10/62 (16.1) 7/17 (41.2) 4/57 (7.0) 7/33 (21.2) 4/41 (9.8) 1/ 4 (25.0) 10/70 (14.3) DD 6/12 (50.0) 14/62 (22.6) 9/17 (52.9) 11/57 (19.3) 12/33 (36.4) 8/41 (19.5) 2/ 4 (50.0) 18/70 (25.7) HL 1/12 (8.3) 6/62 (9.7) 0/17 (0) 7/57 (12.3) 6/33 (18.2) 1/41 (2.4) 0/ 4 (0) 7/70 (10.0) 697 Blindness 2/12 (16.7) 2/62 (3.2) 3/17 (17.7) 1/57 (1.8) 3/33 (8.1) 1/41 (2.4) 1/ 4 (25.0) 3/70 (4.3) *The rate of poor outcome in the entire cohort was 34/80 (43%) Abbreviations: OR, odds ratio; Cl, confidence interval; CP, cerebral palsy; DD, delayed development; HL, hearing loss; BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; PNAC, parenteral nutrition associated cholestasis 17 ELBW infants who developed BPD, 5 infants died after a postmenstrual age of 36 weeks and thus the mortality rate was 29.4 %. Of the 18 patients who developed brain injury, 1 patient died after a postmenstrual age of 36 weeks (5.6%). Of the 17 remaining patients, 7 patients had CP (41.2%). Of the 37 patients who developed ROP, 4 patients died (10.8%) and 3 showed blindness (8.1%) (Table 3). 3. The significance of the combination of morbidities for long term prognosis To adjust the effect of neonatal morbidities on each other, multiple logistic regression analysis was performed on the relationship of the 4 neonatal morbidities and poor long term prognosis. Severe BPD, severe brain injury, and severe ROP were significantly associated with poor long term outcomes, and the odds ratio was more increased [BPD, OR 4.9 (95% CI, 1.0-22.6), P =0.044; brain injury, OR 13.2 (95% CI, 3.0-57.3),P <.001; severe ROP, OR 5.3 (95% CI, 1.6-18.1), P =0.007]. After the removal of the effect of neonatal morbidities affecting each other, the correlation of the 3 neonatal morbidities to poor outcomes became higher than in univariate analysis. However, in multiple logistic regression analysis, PNAC was not significantly associated with poor long term outcomes [OR 3.4 (95% CI, 0.5-22.7), P =0.215]. As the morbidity count increased, the rate of poor long term outcomes also increased and they were significantly associated [OR 5.2 (95% CI, 2.2-11.9),P <0.001] (Table 4). Examining the rate of poor outcomes according to the com- bination of neonatal morbidities, it was found that in cases who were not affected by the 4 neonatal morbidities, 9% showed poor outcomes. On the other hand, poor outcome was seen in 46% of cases affected with any one of these 4 morbidities, 69 % of cases affected with 2 morbidities of any combination, and 100 % in Table 4. Logistic Regression Analysis of Long-term Outcome Model type, Terms Individual morbidities Intercept BPD Brain injury Severe ROP Severe PNAC Morbidity count* Intercept Morbidity count Regression coefficient (SE) -2.18 (0.58) 1.58 (0.79) 2.58 (0.75) 1.68 (0.62) 1.21 (0.98) -1.98 (0.51) 1.64 (0.43) OR (95% CI) P value 4.9 (1.0-22.6) 13.2 (3.0-57.3) 5.3 (1.6-18.1) 3.4 (0.5-22.7) 5.2 (2.2-11.9) 0.044 <.001 0.007 0.215 <.001 *Comprises the number present of BPD, brain injury, severe ROP and severe PNAC. Abbreviations: OR, odds ratio; Cl, confidence interval; BPD, bronch- opulmonary dysplasia; ROP, retinopathy of prematurity; PNAC, parenteral nutrition associated cholestasis cases affected with 3 morbidities of any combination (Table 5, Fig. 1). Additionally, the morbidity count predicted the poor outcomes equally well in each of the 2 strata for birth weight (<750 g) and gestational age (<28 weeks) (Fig. 2). Discussion The increased survival rate of ELBW infants highlights the necessity of the consideration of quality of life in ELBW infants1-6). We examined the prognostic impact of severe BPD, severe brain injury, severe ROP, and severe PNAC on poor outcomes such as late death or neurodevelopmental impairment in ELBW infants between 18 and 24 months of corrected age. Until now, birth weight and gestational age have traditionally been used as strong indicators for the risk of neonatal death13). Scoring systems use physiologic abnormalities (hypotension-