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Objective : To assess whether very low birth weight (VLBW) increases the risk of hospitalization at school age. Design : Prospective, multisite cohort study. Participants : Selected from a previous multisite, hospital-based trial, 611 VLBW children, and, from a prior representative sample, 724 children who weighed 1501 to 2500 gm and 533 who welghed >2500 gm. All the children were recontacted at 8 to 10 years of age for this study. Methods : Maternal interview with the use of standardized questions. Main outcome : Hospitalization in year before interview. Results : The VLBW children were three or four times more likely to be rehospitalized than children of normal birth weight, both in the year before the interview (7% vs 2%) and since birth (50% to 60% vs 22%). Morbidity and Medicald coverage increased the risk of hospitalization in the year before the interview; non-white race decreased it. After control for other factors, however, lower birth weight remained a significant risk factor for hospitalization. Conclusions : The VLBW children continue to have an increased risk of hospitalization; the risk is similar in magnitude to that seen in infancy.

Severity-of-illness scales have proven valuable able in assessing clinical outcomes and resource consumption in adult and pediatric intensive care, but they have been less extensively developed for neonatal care. The National Therapeutic Intervention Scoring System (NTISS) was created by modifying the Therapeutic Intervention Scoring System (TISS). From the 76 original TISS items, 42 were deleted and 28 added to form the NTISS. Like TISS, NTISS assigns score points from 1 to 4 for various intensive care therapies. Admission-day NTISS scores were calculated for 1643 newborns admitted to three neonatal intensive care units (NICUs) between November 1, 1989, and September 30, 1990. NTISS scores ranged from 0 to 47 with a mean of 12.3 ± 8.7 (SD). There was little correlation with birth weight (r = -.11) or gestational age (r = -.17), but NTISS scores were highly correlated with expected markers of illness severity, including mortality risk estimates by neonatal attending physicians (r = .70, P < .0001), in-hospital mortality rates (P < .05), and a measure of nursing acuity (Medicus) (r = .05), and a measure of nursing acuity (Medicus) (r = .69, P < .0001). In addition, admission-day NTISS scores were found to be predictive of both NICU length of stay (r = .37, P < .0001) and total hospital charges for survivors (r = .65, P < .0001). It is concluded that NTISS is a valid measure of therapeutic intensity that is independent of birth weight and can be used as an indicator of neonatal illness severity and resource utilization. Further validation in other NICUs is required.

Summary. Longer-term follow-up of infants with specific health concerns, such as low birthweight, is critical to assessing the effect of medical interventions. This report examines the approach of reconstructing previously studied cohorts in terms of the factors discriminating between respondents and non-respondents. Follow-up was attempted during 1987-1988 for 1875 children born during a 6-month period in 1978 in three geographically defined regions in the United States, for whom 1-year assessments of health and developmental status were obtained at 1 year of age as part of a previous study. For a 25% sample, participation involved a clinic visit for developmental assessments; for the remainder an interview by telephone or home visit. Follow-up was obtained for 72.5% of the cohort. Refusal rates were low (7%); most non-response was due to an inability to locate the families. Predictors of non-response reflected primarily low socio-economic status; completion rates were not influenced by mode of assessment. The role of a tracing agency is discussed. We conclude that cohort reconstruction is feasible with response rates comparable to some prospective studies with ongoing cohort maintenance.

Background. Low birth weight is a major determinant of neonatal mortality. Yet birth weight, even in conjunction with other demographic markers, is inadequate to explain the large variations in neonatal mortality between intensive care units. This variation probably reflects differences in admission severity. The authors have recently developed the Score for Neonatal Acute Physiology (SNAP), an illness severity index specific for neonatal intensive care, and demonstrated illness severity to be a major determinant of neonatal mortality. Objective. To define the relative contributions of birth weight and illness severity to the risk of neonatal mortality and to identify other significant independent risk factors. Methods. Logistic regression was used to analyze data from a cohort of 1621 consecutive admissions to three neonatal intensive care units (92 deaths), to test six alternative predictive models. The best logistic model was then used to develop a simple additive clinical score, the SNAP Perinatal Extension (SNAP-PE). Results. These analyses demonstrated that birth weight and illness severity are powerful independent predictors across a broad range of birth weights and that their effects are additive. Below 750 g, there is an interaction between birth weight and SNAP. Other factors that showed independent predictive power were low Apgar score at 5 minutes and small size for gestational age. Separate derivation and test samples were used to demonstrate that the SNAP-PE is comparable to the best logistic model and has a sensitivity and specificity superior to either birth weight or SNAP alone (receiver-operator characteristic area .92 ± .02) as well as excellent goodness of fit. Conclusion. This simplified clinical score provides accurate mortality risk estimates for application in a broad array of clinical and research settings.

Telephone interviews offer an economical method of obtaining information, but little published experience addresses the use of telephone interviews for the sometimes lengthy questionnaires composed of scales with multiple-category items often required in developmental and behavioral research. In a study of the outcomes of very low birth weight infants, circumstances required that we administer a questionnaire, including seven scales composed of several Likert-type items each, to a substantial portion of the study population. Those contacted by telephone (n = 1067) differed from those responding face-to-face (n = 822) in being less likely to have a very low birth weight child and more likely to be white and of higher maternal education. The length of the interview was only slightly shorter by telephone (60.7 +/- 27.9 vs 66.4 +/- 21.0 minutes, p < .001), but respondent fatigue, as indicated by lower completion rates for scales at the end of the interview (92.5%) compared with those near the beginning (99.5%) did not differ by mode. Internal consistency of parental response (Cronbach's alpha) was high for most scales and did not differ by mode. Because assignment to mode was not random, other factors may influence our findings. However, high completion rates and comparable consistency of response supports the use of telephone interviews.

Objective. —To assess the effect of improved survival of increasingly premature infants by examining the outcomes at school age of a large group of children born at different birth weights. Design. —Inception cohort. Setting/Participants. —Participants were selected from two previously studied multisite cohorts: very low—birth-weight (≤1500 g) children referred to participating intensive care units and heavier birth-weight children drawn from a stratified random sample of births in geographically defined regions. Follow-up at 8 to 10 years of age was by a combination of telephone interview and home/clinic visits for 65.1% (1868) of those eligible. Main Outcome Measures. —The presence or absence of 17 specific conditions, limitations in activities of daily living due to health, mental health (affective health, behavior problems), and, for a subset, IQ scores. Results. —Decreasing birth weight was associated with an increased morbidity for all measures except affective health; those with birth weights of 1500 g or less were more likely to experience multiple health problems. Maternal educational attainment did not influence the association of birth weight with morbidity except for IQ among children whose birth weight was above 1000 g, for which socioeconomic disadvantage worsened the status of all children irrespective of birth weight. Conclusions. —Children born at lower birth weights experience increased morbidity at early school age. These results reinforce the importance of postdischarge, early intervention programs to reduce the risk of these later health problems. (JAMA. 1992;267:2204-2208)

Objective. To describe the mental and emotional well-being of children born at different birth weights assessed at school age and to identify neonatal, intervening health, and sociodemographic and environmental factors associated with mental and emotional well-being. Methods. To address this issue, we used a prospective cohort study involving two previously studied cohorts, which were recontacted at 8 to 10 years of age to provide a multisite sample of 247 children weighing 1000 g or less at birth, 364 weighing 1001 to 1500 g, 724 weighing 1501 to 2500 g, and 533 weighing more than 2500 g. Maternal reports were obtained on three standardized measures of mental and emotional well-being (the Rand General Well-being Scale, the Behavior Problem Index, and the Harter Scale of Child Competence) and on intervening health, sociodemographic, and environmental variables. Neonatal variables were derived from records at birth. Statistical techniques included analysis of variance and ordinary least squares multiple regression. Results. Lower birth weight children did not differ on the General Well-being Scale but were more likely to have behavior problems and to be considered less competent. Other important correlates of mental and emomotional well-being included childhood illness, maternal mental health, home environment score, and exposure to household cigarette smoking. Conclusion. Although lower birth weight children have poorer mental and emotional well-being, a substantial portion of this adverse outcome reflects modifiable environmental factors.