Active Precipitation of Radiation Belt Electrons Using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers.

Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.

Cumulative illness severity and progression from moderate to severe retinopathy of prematurity.

OBJECTIVE: To test cumulative neonatal illness severity (IS) and IS fluctuation as predictors of progression from moderate to severe retinopathy of prematurity (ROP). METHODS: Data from research databases and medical record review were collected for infants from four neonatal intensive care unit (NICUs) admitted between 1995 and 2001 and diagnosed with prethreshold ROP. Cumulative neonatal IS measured using daily Scores for Neonatal Acute Physiology (SNAP) for the first 28 days of life, and IS fluctuation as assessed by summing changes between daily SNAP scores, were tested as predictors of progression to threshold ROP using logistic regression. RESULTS: Infants progressing to threshold (n=79), compared to those not progressing to threshold (n=130), had significantly (P<0.05) lower gestational ages (25.2+/-1.1 versus 25.8+/-1.4 weeks), higher cumulative neonatal SNAP (255+/-77 versus 224+/-63 weeks) and had more severe hospitalizations as indicated by diagnoses and medical management. In regression analysis, gestational age, chronological age and presence of plus disease at first diagnosis of prethreshold were associated with development of threshold. After adjusting for these factors, cumulative neonatal SNAP was significantly associated with progression to threshold. However, addition of cumulative SNAP to the model only increased receiver-operating characteristic curve area from 0.77 to 0.78 (NS). Other factors, including SNAP fluctuation, were not associated with progression to threshold after adjustment using this model. CONCLUSIONS: Cumulative neonatal IS, as measured by cumulative SNAP, is an independent risk factor for progression from moderate to severe ROP. However, cumulative IS does not enhance assessment of risk for ROP progression after adjusting for simpler clinical factors.

The primary amine metabolite of sibutramine stimulates lipolysis in adipocytes isolated from lean and obese mice and in isolated human adipocytes.

Sibutramine is a satiety-inducing serotonin-noradrenaline reuptake inhibitor that acts predominantly via its primary and secondary metabolites. This study investigates the possibility that sibutramine and/or its metabolites could act directly on white adipose tissue to increase lipolysis. Adipocytes were isolated by a collagenase digestion procedure from homozygous lean (+/+) and obese-diabetic OB/OB mice, and from lean nondiabetic human subjects. The lipolytic activity of adipocyte preparations was measured by the determination of glycerol release over a 2-hour incubation period. The primary amine metabolite of sibutramine M2, caused a concentration-dependent stimulation of glycerol release by murine lean and obese adipocytes (maximum increase by 157+/-22 and 245+/-16%, respectively, p<0.05). Neither sibutramine nor its secondary amine metabolite M1 had any effect on lipolytic activity. Preliminary studies indicated that M2-induced lipolysis was mediated via a beta-adrenergic action. The non-selective beta-adrenoceptor antagonist propranolol (10 (-6) M) strongly inhibited M2-stimulated lipolysis in lean and obese murine adipocytes. M2 similarly increased lipolysis by isolated human omental and subcutaneous adipocytes (maximum increase by 194+/-33 and 136+/-4%, respectively, p<0.05) with EC50 values of 12 nM and 3 nM, respectively. These results indicate that the sibutramine metabolite M2 can act directly on murine and human adipose tissue to increase lipolysis via a pathway involving beta-adrenoceptors.

Association between variants in the genes for adiponectin and its receptors with insulin resistance syndrome (IRS)-related phenotypes in Mexican Americans.

AIMS/HYPOTHESIS: The aim of this study was to examine whether genetic variation in ADIPOQ, ADIPOR1 and ADIPOR2 may contribute to increased susceptibility to components of the insulin resistance syndrome (IRS). MATERIALS AND METHODS: We genotyped single-nucleotide polymorphisms (SNPs) in ADIPOQ, ADIPOR1 and ADIPOR2 in Mexican American subjects (N=439) and performed an association analysis of IRS-related traits. RESULTS: Of the eight SNPs examined in the ADIPOQ gene, rs4632532 and rs182052 exhibited significant associations with BMI (p=0.029 and p=0.032), fasting specific insulin (p=0.023 and p=0.026), sum of skin folds (SS) (p=0.0089 and p=0.0084) and homeostasis model assessment of insulin sensitivity (HOMA-%S) (p=0.015 and p=0.016). Two other SNPs, rs266729 and rs2241767, were significantly associated with SS (p=0.036 and p=0.013). SNP rs7539542 of ADIPOR1 was significantly associated with BMI, SS and waist circumference (p=0.025, p=0.047 and p=0.0062). Fourteen of the ADIPOR2 SNPs were found to be significantly (p<0.05) associated with fasting plasma triglyceride concentrations. Four of these SNPs (rs10848569, rs929434, rs3809266 and rs12342) were in high pairwise linkage disequilibrium (r (2)=0.99) and were strongly associated with fasting triglyceride levels (p=0.00029, p=0.00016, p=0.00027 and p=0.00021). Adjusting for the effects of BMI and HOMA-%S on triglyceride concentrations increased significance to p=0.000060 for SNP rs929434. Bayesian quantitative trait nucleotide analysis was used to examine all possible models of gene action. Again, SNP rs929434 provided the strongest statistical evidence of an effect on triglyceride concentrations. CONCLUSIONS/INTERPRETATION: These results provide evidence for association of SNPs in ADIPOQ and its receptors with multiple IRS-related phenotypes. Specifically, several genetic variants in ADIPOR2 were strongly associated with decreased triglyceride levels.

Unstudied infants: outcomes of moderately premature infants in the neonatal intensive care unit.

BACKGROUND: Newborns of 30-34 weeks gestation comprise 3.9% of all live births in the United States and 32% of all premature infants. They have been studied much less than very low birthweight infants. OBJECTIVE: To measure in-hospital outcomes and readmission within three months of discharge of moderately premature infants. DESIGN: Prospective cohort study including retrospective chart review and telephone interviews after discharge. SETTING: Ten birth hospitals in California and Massachusetts. PATIENTS: Surviving moderately premature infants born between October 2001 and February 2003. MAIN OUTCOME MEASURES: (a) Occurrence of assisted ventilation during the hospital stay after birth; (b) adverse in-hospital outcomes-for example, necrotising enterocolitis; (c) readmission within three months of discharge. RESULTS: With the use of prospective cluster sampling, 850 eligible infants and their families were identified, randomly selected, and enrolled. A total of 677 families completed a telephone interview three months after hospital discharge. During the birth stay, these babies experienced substantial morbidity: 45.7% experienced assisted ventilation, and 3.2% still required supplemental oxygen at 36 weeks. Readmission within three months occurred in 11.2% of the cohort and was higher among male infants and those with chronic lung disease. CONCLUSIONS: Moderately premature infants experience significant morbidity, as evidenced by high rates of assisted ventilation, use of oxygen at 36 weeks, and readmission. Such morbidity deserves more research.

Moderately premature infants at Kaiser Permanente Medical Care Program in California are discharged home earlier than their peers in Massachusetts and the United Kingdom.

OBJECTIVE: To compare gestational age at discharge between infants born at 30-34(+6) weeks gestational age who were admitted to neonatal intensive care units (NICUs) in California, Massachusetts, and the United Kingdom. DESIGN: Prospective observational cohort study. SETTING: Fifty four United Kingdom, five California, and five Massachusetts NICUs. SUBJECTS: A total of 4359 infants who survived to discharge home after admission to an NICU. MAIN OUTCOME MEASURES: Gestational age at discharge home. RESULTS: The mean (SD) postmenstrual age at discharge of the infants in California, Massachusetts, and the United Kingdom were 35.9 (1.3), 36.3 (1.3), and 36.3 (1.9) weeks respectively (p = 0.001). Compared with the United Kingdom, adjusted discharge of infants occurred 3.9 (95% confidence interval (CI) 1.4 to 6.5) days earlier in California, and 0.9 (95% CI -1.2 to 3.0) days earlier in Massachusetts. CONCLUSIONS: Infants of 30-34(+6) weeks gestation at birth admitted and cared for in hospitals in California have a shorter length of stay than those in the United Kingdom. Certain characteristics of the integrated healthcare approach pursued by the health maintenance organisation of the NICUs in California may foster earlier discharge. The California system may provide opportunities for identifying practices for reducing the length of stay of moderately premature infants.

[Assessing the impact of delivery unit size on neonatal survival: estimation of potentially avoidable deaths in Hessen, Germany, 1990-2000]. / Hat die Grösse der Geburtsklinik Einfluss auf das neonatale Uberleben? Schätzung von "vermeidbaren" Todesfällen in Hessen 1990-2000.

BACKGROUND AND OBJECTIVE: There are only few analyses from Germany on the impact of delivery unit size on neonatal outcome. The objective of this study was to evaluate the influence of delivery unit size on neonatal survival in Germany. PATIENTS AND METHODS: Data from the perinatal birth register for Hessen for 1990-2000 comprising 640554 births, and the Neonatal Survey for 1989-1997 in Hessen were used. Potentially avoidable deaths were assessed according to delivery unit size and birth weight category. Additionally trend analyses and an extrapolation to potentially avoidable deaths in all of Germany were performed. RESULTS: Compared to large delivery units, smaller ones showed higher risk adjusted mortality rates. Calculation of potentially avoidable deaths gave an estimate of 257 early neonatal deaths in 11 years. Although trend analyses revealed a decline of potentially avoidable deaths, an extrapolation of such deaths for all of Germany still yielded an estimate of more than 300 potentially avoidable deaths per year using data from 1997-2000 only. CONCLUSION: A valid inference as to the magnitude of the observed effect remains even in the face of a very cautious interpretation of our results. During the study period of 11 years, more than 200 neonatal deaths could be attributed to the fact that births in Hessen are dispersed among many small hospitals. If this pattern of births in small units is common throughout Germany, it suggests that several hundred neonatal deaths per year may be attributed to this risk factor when extrapolating these results nationally. Further research is necessary to describe the nation-wide magnitude of this problem and to identify the role of underlying causal risk factors more precisely. Additionally policy discussions regarding structural changes in obstetrical care should be undertaken in the meantime, aimed at reducing the observed mortality rates.

Inter-neonatal intensive care unit variation in discharge timing: influence of apnea and feeding management.

BACKGROUND: Premature infants need to attain both medical stability and maturational milestones (specifically, independent thermoregulation, resolution of apnea of prematurity, and the ability to feed by mouth) before safe discharge to home. Current practice also requires premature infants to be observed in hospital before discharge for several days (margin of safety) after physiologic maturity is recognized. OBJECTIVE: To compare postmenstrual age (PMA) at discharge in a homogeneous population of premature infants cared for in different neonatal intensive care units (NICUs) and to assess the impact on hospital stay of the recognition and recording of physiologic maturity and the required margin of safety. METHODS: We studied premature infants delivered at 30 to 34 6/7 weeks gestational age (GA), free of significant medical or surgical complications. Medical records of 30 eligible infants consecutively discharged from the hospital before July 1997 from each of 15 NICUs in Massachusetts (9 level 2 and 6 level 3) were reviewed. RESULTS: A total of 435 infants were included in the study sample. Mean (+/- standard deviation) GA and birth weight of the study population were 33.2 +/- 1.2 weeks and 2024 +/- 389 g, respectively. Infants were discharged at a similar PMA regardless of GA at birth. Considerable variation in the PMA at discharge between hospital sites was observed (range, 35.2 +/- 0.5 weeks to 36.5 +/- 1.2 weeks). Despite the homogeneous study population, hospitals in which infants had the latest PMA at discharge also recorded mature cardiorespiratory and feeding behavior at an older age. Longer duration of pulse oximetry use was associated with later resolution of apnea. Differences in the duration of the margin of safety between sites did not contribute to variation in hospital stay. CONCLUSION: NICUs vary widely in length of hospital stay for healthy premature infants. We speculate that this variation results in part from differences in monitoring for and documentation of apnea of prematurity and feeding behavior.

Variations in prevalence of hypotension, hypertension, and vasopressor use in NICUs.

OBJECTIVE: Very low birth weight infants are vulnerable to hypotension and its associated complications. Vasopressors are used to raise blood pressure (BP), but indications for use are uncertain. Our objectives were (1) to study variations in BP stability among NICUs, (2) to investigate inter-NICU differences in vasopressor use, and (3) to address the association between intraventricular hemorrhage (IVH) and abnormal BPs. STUDY DESIGN: A total of 1288 infants with birth weight <1500 g were admitted to six NICUs in Massachusetts and Rhode Island over 21 months. The lowest and highest mean BPs were collected within the first 12 hours. Also recorded were the use of vasopressors within the first 24 hours and the occurrence of IVH. Logistic regressions were used to model outcomes, controlling for gestational age and illness severity using the Score for Neonatal Acute Physiology. RESULTS: Two of the six NICUs had significantly higher percentages of infants with at least one hypotensive BP, with prevalences of 24% to 45%. Percentages of infants treated with vasopressors ranged from 4% to 39%. This range of vasopressor use could not be explained by inter-NICU differences in birth weight, illness severity, or rates of hypotension. We found a borderline association between severe IVH and hypotension (odds ratio 1.6, p=0.055), but not between severe IVH and hypertension. CONCLUSION: Wide differences exist in the prevalence of hypotension, hypertension, and vasopressor use among NICUs. We also found an association between hypotension and IVH, but not between hypertension and IVH.

A critical review of cost reduction in neonatal intensive care. I. The structure of costs.

Neonatal intensive care is expensive. In the current era of intense cost containment in hospital care, neonatologists and hospital administrators are under intense pressure to find strategies for cost reduction for neonatal services. Few neonatal clinicians are trained in economics, management, or accounting, and few hospital administrators are familiar with neonatal intensive care. In this review, we describe the structure and sources of hospital costs and the accounting systems needed to isolate and measure such costs. We discuss where efficiencies might be found and consider specific issues in capitated settings such as health maintenance organizations in the United States, the Canadian health care system and the National Health System in the United Kingdom.

A critical review of cost reduction in neonatal intensive care. II. Strategies for reduction.

Neonatal intensive care is extremely expensive; there is both a financial and an ethical obligation to practice efficiently. In the current era of intense cost containment in hospital care, neonatologists and hospital administrators are under pressure to find strategies for cost reduction for neonatal services. In this review, we address reducing discretionary admissions, the high costs of low-cost testing, minimizing use of selected high-cost technologies (ventilators and parenteral nutrition), shortening length of stay, and optimizing nursing allocation.

Relationship of race and severity of neonatal illness.

OBJECTIVE: Our goal was to determine whether there are racial differences in the severity of illness on admission for premature newborn infants independent of gestational age. STUDY DESIGN: The study population consisted of all African American and Caucasian singleton infants with gestational ages <34 weeks who were admitted to the neonatal intensive care unit at Brigham and Women's Hospital between December 1994 and November 1995. Illness severity was measured with a neonatal severity of illness score, the SNAP score (Score for Neonatal Acute Physiology). The SNAP score is a physiologic scoring system that ranks the worst physiologic derangements in each organ system in the first 12 hours of life. It is an objective measure of neonatal illness severity with scores ranging from 0 (healthy) to 42 (most severely ill). Student t tests, chi(2) analysis, and Fisher exact tests were used to assess statistical significance. Linear and logistic regression analyses were used to examine associations while confounding factors were controlled for. RESULTS: There were 129 (79%) Caucasian and 36 (22%) African American newborns included in the analysis. Caucasian newborns had significantly higher mean SNAP scores than African American newborns (8.8 vs. 6.3; P <.05). Compared with African American newborns, Caucasian newborns were more than twice as likely to have a SNAP score >10 (33% vs. 14%; P <.05). In a linear regression analysis in which we controlled for gestational age, birth weight, preterm premature rupture of membranes, preterm labor, preeclampsia, intrapartum fever > or =100.4 degrees F, route of delivery, and other maternal and fetal factors, African American newborns were predicted to have a SNAP score that was on average 3.0 points lower than that of Caucasian newborns (P =.005). In a logistic regression in which we controlled for the above-mentioned confounders, African American newborns were only 14% as likely to have a SNAP score >10 when compared with Caucasian newborns (odds ratio, 0.14; 95% confidence interval, 0.04-0.51). CONCLUSIONS: Over a broad range of prematurity, Caucasian newborns were more ill than African American newborns on admission to the neonatal intensive care unit.

SNAP-II and SNAPPE-II: Simplified newborn illness severity and mortality risk scores.

OBJECTIVES: Illness severity scores for newborns are complex and restricted by birth weight and have dated validations and calibrations. We developed and validated simplified neonatal illness severity and mortality risk scores. The primary outcome was in-hospital mortality. STUDY DESIGN: Thirty neonatal intensive care units in Canada, California, and New England collected data on all admissions during the mid 1990s; patients moribund at birth or discharged to normal newborn care in <24 hours were excluded. Starting with the 34 data elements of the Score for Neonatal Acute Physiology (SNAP), we derived the most parsimonious logistic model for in-hospital mortality using 10,819 randomly selected Canadian cases. SNAP-II includes 6 physiologic items; to this are added points for birth weight, low Apgar score, and small for gestational age to create a 9-item SNAP-Perinatal Extension-II (SNAPPE-II). We validated SNAPPE-II on the remaining 14,610 cases and optimized the calibration. RESULTS: In all birth weights, SNAPPE-II had excellent discrimination and goodness of fit. Area under the receiver operator characteristic curve was .91 +/- 0.01. Goodness of fit (Hosmer-Lemeshow) was 0.90. CONCLUSIONS: SNAP-II and SNAPPE-II are empirically validated illness severity and mortality risk scores for newborn intensive care. They are simple, accurate, and robust across populations.

Economics of prematurity in the era of managed care.

Both the acute intensive care of premature infants and the management of their long-term medical and educational sequelae are costly. Because neonatal intensive care is very effective in reducing mortality, however, its cost effectiveness as described previously is actually quite favorable when compared with other well-accepted medical interventions, such as coronary artery bypass grafting and renal dialysis. This article has highlighted the relatively scant literature on which those estimates of costs and cost effectiveness of both neonatal intensive care and its component interventions rest. This is particularly true with respect to long-term resource use by graduates of NICUs. Without such information, we cannot hope to allocate resources in a way that ensures optimal care of this vulnerable population.

Variation in the use of alternative levels of hospital care for newborns in a managed care organization.

OBJECTIVE(S): To assess the extent to which variation in the use of neonatal intensive care resources in a managed care organization is a consequence of variation in neonatal health risks and/or variation in the organization and delivery of medical care to newborns. STUDY DESIGN: Data were collected on a cohort of all births from four sites in Kaiser Permanente by retrospective medical chart abstraction of the birth admission. Likelihood of admission into a neonatal intensive care unit (NICU) is estimated by logistic regression. Durations of NICU stays and of hospital stay following birth are estimated by Cox proportional hazards regression. RESULTS: The likelihood of admission into NICU and the duration of both NICU care and hospital stay are proportional to the degree of illness and complexity of diagnosis. Adjusting for variation in health risks across sites, however, does not fully account for observed variation in NICU admission rates or for length of hospital stay. One site has a distinct pattern of high rates of NICU admissions; another site has a distinct pattern of low rates of NICU admission but long durations of hospital stay for full-term newborns following NICU admission as well as for all newborns managed in normal care nurseries. CONCLUSIONS: Substantial variations exist among sites in the risk-adjusted likelihood of NICU admission and in durations of NICU stay and hospital stay. Hospital and NICU affiliation (Kaiser Permanente versus contract) or affiliation of the neonatologists (Kaiser Permanente versus contract) could not explain the variation in use of alternative levels of hospital care. The best explanation for these variations in neonatal resource use appears to be the extent to which neonatology and pediatric practices differ in their policies with respect to the management of newborns of minimal to moderate illness.

Intrapartum maternal fever and neonatal outcome.

OBJECTIVE: Much of fever during term labor may not be infectious but rather a consequence of the use of epidural analgesia. Therefore, we investigated the association of elevated maternal intrapartum temperature with neonatal outcome when the infant does not develop an infection. METHODS: We studied 1218 nulliparous women with singleton, term pregnancies in a vertex presentation and spontaneous labor. Women were excluded if their temperature was >99.5 degrees F at admission for delivery, if they were diabetic or had an active genital herpes infection or if their infant developed a neonatal infection, had a congenital infection, or had a major malformation. Maximum intrapartum temperature was categorized as: 101 degrees F. RESULTS: During labor, 123 women (10.1%) developed a fever >100.4 degrees F; 62 (5.1%) women had a maximum temperature of 100.5 degrees F to 101 degrees F and 61 (5.0%) women had a maximum temperature >101 degrees F. Of febrile women, 97.6% had received epidural analgesia for pain relief. Infants of women developing a fever >100.4 degrees F were more likely to have a 1-minute Apgar score <7 (22.8% for >100.4 degrees F vs 8.0% for afebrile) and to be hypotonic after delivery (4.8% for >100.4 degrees F vs.5% for afebrile). Compared with infants of afebrile women, infants whose mothers' maximum temperature was >101 degrees F were more likely to require bag and mask resuscitation (11.5% vs 3.0%) and to be given oxygen therapy in the nursery (8.2% vs 1.3%). We also found a higher rate of neonatal seizure with fever (3.3% vs.2%), but the number of infants with seizure was small (n = 4). All associations remained essentially the same after controlling for confounding in logistic regression analyses. CONCLUSIONS: Intrapartum maternal fever, particularly if >101 degrees F, was associated with a number of apparently transient adverse effects in the newborn. Larger studies are needed to investigate the association of intrapartum fever with neonatal seizures and to determine whether any lasting injury to the fetus may occur.

Occurrence of nosocomial bloodstream infections in six neonatal intensive care units.

BACKGROUND: Nosocomial bloodstream infections (NBSIs) occur frequently in neonatal intensive care units (NICUs) and are associated with substantial morbidity and mortality. Little has been published regarding variation in NBSI among institutions. OBJECTIVE: To determine NBSI incidence among six NICUs and to explore how much variation is explained by patient characteristics and NICU practice patterns. METHODS: From October, 1994, to June, 1996, six regional NICUs prospectively abstracted clinical records of all neonates weighing <1,500 g. Occurrence of NBSI, defined as first positive culture occurring >48 h after admission, was analyzed in relation to baseline patient characteristics and several common therapeutic interventions. Variables significant in univariate analyses were analyzed by Cox proportional hazards regression. RESULTS: There were 258 NBSIs (incidence, 19.1%) among 1,354 inborn first admissions. Incidence varied significantly by site, from 8.5 to 42%. Birth weight, Broviac catheter use and parenteral nutrition were significantly associated with NBSI (P < 0.05). When controlling for these variables interinstitutional variation in NBSI occurrence decreased but remained significant. CONCLUSIONS: Neonatal NBSI incidence varies substantially among institutions despite adjustment for length of stay and some known risk factors. The uses of Broviac catheters and especially intravenous nutrition supplements were significant determinants of NBSI risk.

Cost-effectiveness and implications of newborn screening for prolongation of QT interval for the prevention of sudden infant death syndrome.

OBJECTIVE: To determine the cost-effectiveness of universal and high-risk neonatal electrocardiographic (ECG) screening for QT prolongation as a predictor of sudden infant death syndrome (SIDS) risk in a theoretical group of neonates. STUDY DESIGN: Incremental cost-effectiveness analysis with decision analytic modeling. A hypothetical cohort of healthy, term infants was modeled, comparing options of no screening, high-risk neonate screening, and universal screening. The high-risk strategy is speculative, because no currently accepted methodology is known for identifying infants at high risk for SIDS. Given the uncertain mechanisms of association between prolonged corrected QT interval (QTc) and SIDS, analyses were repeated under different assumptions. Sensitivity analyses were also performed on all input variables for both costs and effectiveness. RESULTS: Under the assumption that neonatal electrocardiographic screening detects long QT syndrome responsive to conventional therapy, the cost-effectiveness of high-risk screening was $3403 per life year gained, whereas universal screening cost $18,465 per additional life year gained. However, if the effectiveness of SIDS therapy falls below 10%, the cost-effectiveness deteriorates to $28,376 per life year saved for the high-risk strategy and $118,900 for universal screening. The analyses were robust to a broad array of sensitivity analyses. CONCLUSIONS: The acceptability of the cost-effectiveness of neonatal electrocardiographic screening is heavily dependent on the pathophysiologic mechanism of SIDS and on the efficacy of monitoring and antiarrhythmic treatment. The nature of this association must be elucidated before routine neonatal electrocardiographic screening is warranted.