Tips for learners of evidence-based medicine: 2. Measures of precision (confidence intervals).
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Clinical Trials as Topic↗
Biomedical subjects
Thomas B Newman
Publications and source records attributed to Thomas B Newman.
Management and outcomes of care of fever in early infancy.
CONTEXT: Fever in infants challenges clinicians in distinguishing between serious conditions, such as bacteremia or bacterial meningitis, and minor illnesses. To date, the practice patterns of office-based pediatricians in treating febrile infants and the clinical outcomes resulting from their care have not been systematically studied. OBJECTIVES: To characterize the management and clinical outcomes of fever in infants, develop a clinical prediction model for the identification of bacteremia/bacterial meningitis, and compare the accuracy of various strategies. DESIGN: Prospective cohort study. SETTING: Offices of 573 practitioners from the Pediatric Research in Office Settings (PROS) network of the American Academy of Pediatrics in 44 states, the District of Columbia, and Puerto Rico. PATIENTS: Consecutive sample of 3066 infants aged 3 months or younger with temperatures of at least 38 degrees C seen by PROS practitioners from February 28, 1995, through April 25, 1998. MAIN OUTCOME MEASURES: Management strategies, illness frequency, and rates and accuracy of treating bacteremia/bacterial meningitis. RESULTS: The PROS clinicians hospitalized 36% of the infants, performed laboratory testing in 75%, and initially treated 57% with antibiotics. The majority (64%) were treated exclusively outside of the hospital. Bacteremia was detected in 1.8% of infants (2.4% of those tested) and bacterial meningitis in 0.5%. Well-appearing infants aged 25 days or older with fever of less than 38.6 degrees C had a rate of 0.4% for bacteremia/bacterial meningitis. Frequency of other illnesses included urinary tract infection, 5.4%; otitis media, 12.2%; upper respiratory tract infection, 25.6%; bronchiolitis, 7.8%; and gastroenteritis, 7.2%. Practitioners followed current guidelines in 42% of episodes. However, in the initial visit, they treated 61 of the 63 cases of bacteremia/bacterial meningitis with antibiotics. Neither current guidelines nor the model developed in this study performed with greater accuracy than observed practitioner management. CONCLUSIONS: Pediatric clinicians in the United States use individualized clinical judgment in treating febrile infants. In this study, relying on current clinical guidelines would not have improved care but would have resulted in more hospitalizations and laboratory testing.
Bacteremia↗
Impact of pulse oximetry and oxygen therapy on length of stay in bronchiolitis hospitalizations.
BACKGROUND: Infants hospitalized with bronchiolitis are frequently monitored with a pulse oximeter. However, there is little consensus on an acceptable lower limit of oxygenation. No previous studies have examined how the use of pulse oximetry and supplemental oxygen therapy affects length of stay. OBJECTIVE: To determine the extent to which bronchiolitis hospitalizations are prolonged by a perceived need for supplemental oxygen based on pulse oximetry readings. Design and Patients Retrospective case series of subjects younger than 2 years who were hospitalized with bronchiolitis at an academic medical center. Two investigators independently reviewed the hospitalization records of 73 infants and determined at what point an infant met all discharge criteria except oxygenation. We then calculated the extent to which hospitalizations were prolonged by a perceived need for supplemental oxygen therapy based on pulse oximetry readings alone. RESULTS: Sixty-two infants met inclusion criteria. There was high interrater reliability in determining whether hospitalizations were prolonged (kappa = 0.75). In 16 (26%) of 62 patients (95% confidence interval, 15%-37%), the hospitalization was prolonged because of oxygenation concerns. Length of stay was prolonged an average of 1.6 days (range, 1.1-2.0 days) per hospitalization for these 16 patients, or 0.4 day (range, 0.2-0.6 day) per hospitalization for all 62 patients. CONCLUSIONS: Hospitalizations of some infants with bronchiolitis are prolonged by a perceived need for supplemental oxygen therapy based on pulse oximetry readings. Further investigation into outcomes of different levels and durations of oxygen desaturation is needed and would have the potential to reduce practice variability and shorten the length of stay.
Age Distribution↗
Richardson score predicts short-term adverse respiratory outcomes in newborns >/=34 weeks gestation.
OBJECTIVES: To develop a model to predict which newborns >/=34 weeks gestation with respiratory distress will die or will require prolonged (>3 days) assisted ventilation. METHODS: Retrospective cohort study using data from Northern California newborns >/=34 weeks gestation who presented with respiratory distress. We split the cohort into derivation and validation datasets. Bivariate and multivariate data analyses were performed on the derivation dataset. After developing a simple score on the derivation dataset, we applied it to the original as well as to a second validation dataset from Massachusetts. RESULTS: Of 2276 babies who met our initial eligibility criteria, 203 (9.3%) had the primary study outcome (assisted ventilation >3 days or death). A simple score based on gestational age, the lowest PaO 2 /FIO 2 , a variable combining lowest pH and highest PaCO 2 , and the lowest mean arterial blood pressure had excellent performance, with a c-statistic of 0.85 in the derivation dataset, 0.80 in the validation dataset, and 0.80 in the secondary validation dataset. CONCLUSIONS: A simple objective score based on routinely collected physiologic predictors can predict respiratory outcomes in infants >/=34 weeks gestation with respiratory distress.
Continuous Positive Airway Pressure↗
Kernicterus: epidemiological strategies for its prevention through systems-based approaches.
Kernicterus, thought to be due to severe hyperbilirubinemia, is an uncommon disorder with tragic consequences, especially when it affects healthy term and near-term infants. Early identification, prevention and treatment of severe hyperbilirubinemia should make kernicterus a preventable disease. However, national epidemiologic data are needed to monitor any preventive strategies. Recommendations are provided to obtain prospective data on the prevalence and incidence of severe hyperbilirubinemia and associate mortality and neurologic injury using standardized definitions, explore the clinical characteristics and root causes of kernicterus in children identified in the Kernicterus Pilot Registry, identify and test an indicator for population surveillance, validating systems-based approaches to the management of newborn jaundice, and explore the feasibility of using biologic or genetic markers to identify infants at risk for hyperbilirubinemia. Increased knowledge about the incidence and consequences of severe hyperbilirubinemia is essential to the planning, implementation and assessment of interventions to ensure that infants discharged as healthy from their birth hospitals have a safer transition to home, avoiding morbidity due to hyperbilirubinemia and other disorders. At a recent NIHCD-sponsored conference, key questions were raised about kernicterus and the need for additional strategies for its prevention. These questions and an approach to their answers form the basis of this report.
Female↗
Hyperbilirubinemia benchmarking.
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Benchmarking↗
Perinatal stroke in children with motor impairment: a population-based study.
OBJECTIVE: Risk factors for perinatal arterial stroke (PAS) are poorly understood. Most previous studies lack an appropriate control group and include only infants with symptoms in the newborn period. We set out to determine prenatal and perinatal risk factors for PAS. METHODS: In a population-based, case-control study nested within the cohort of 231 582 singleton infants who were born at >or=36 weeks' gestation in Northern California Kaiser hospitals from 1991 to 1998, we searched electronically for children with motor impairment and reviewed their medical records to identify diagnoses of PAS. Control subjects were randomly selected from the study population. A medical record abstractor reviewed delivery records without knowledge of case status. RESULTS: The prevalence of PAS with motor impairment was 17/100,000 live births. Of 38 cases, 26 (68%) presented after 3 months of age with hemiparesis or seizures. All 12 newborns with acute stroke symptoms had seizures. A delayed presentation was more common in children with moderate to severe motor impairment than among infants with only mild motor abnormalities (24 of 31 vs 2 of 7). Prepartum risk factors significantly associated with PAS in multivariate analysis were preeclampsia (odds ratio [OR]: 3.6; 95% confidence interval [CI]: 1.1-11.4) and intrauterine growth restriction (OR: 5.3; 95% CI: 1.5-18.6). Newborns with PAS were also at higher risk of delivery complications, such as emergency cesarean section (OR: 6.8; 95% CI: 2.7-16.6), 5-minute Apgar <7 (OR: 23.6; 95% CI: 4.1-237), and resuscitation at birth (OR: 4.5; 95% CI: 1.6-12.3). CONCLUSIONS: Preeclampsia and intrauterine growth restriction (IUGR) may be independent risk factors for perinatal stroke resulting in motor impairment. Large multicenter studies that include all children with perinatal stroke are needed to determine further the risk factors and outcome of perinatal stroke.
Age of Onset↗
The power of stories over statistics.
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Aircraft↗
Chorioamnionitis and cerebral palsy in term and near-term infants.
CONTEXT: Half of all cases of cerebral palsy (CP) occur in term infants, for whom risk factors have not been clearly defined. Recent studies suggest a possible role of chorioamnionitis. OBJECTIVE: To determine whether clinical chorioamnionitis increases the risk of CP in term and near-term infants. DESIGN, SETTING, AND PATIENTS: Case-control study nested within a cohort of 231 582 singleton infants born at 36 or more weeks' gestation between January 1, 1991, and December 31, 1998, in the Kaiser Permanente Medical Care Program, a managed care organization providing care for more than 3 million residents of northern California. Case patients were identified from electronic records and confirmed by chart review by a child neurologist, and comprised all children with moderate to severe spastic or dyskinetic CP not due to postnatal brain injury or developmental abnormalities (n = 109). Controls (n = 218) were randomly selected from the study population. MAIN OUTCOME MEASURE: Association between clinical chorioamnionitis and increased risk of CP in term and near-term infants. RESULTS: Most CP cases had hemiparesis (40%) or quadriparesis (38%); 87% had been diagnosed by a neurologist and 83% had undergone neuroimaging. Chorioamnionitis, considered present if a treating physician made a diagnosis of chorioamnionitis or endometritis clinically, was noted in 14% of cases and 4% of controls (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.5-10.1; P =.001). Independent risk factors identified in multiple logistic regression included chorioamnionitis (OR, 4.1; 95% CI, 1.6-10.1), intrauterine growth restriction (OR, 4.0; 95% CI, 1.3-12.0), maternal black ethnicity (OR, 3.6; 95% CI, 1.4-9.3), maternal age older than 25 years (OR, 2.6; 95% CI, 1.3-5.2), and nulliparity (OR, 1.8; 95% CI, 1.0-3.0). The population-attributable fraction of chorioamnionitis for CP is 11%. CONCLUSION: Our data suggest that chorioamnionitis is an independent risk factor for CP among term and near-term infants.
Asphyxia Neonatorum↗
Effects and costs of requiring child-restraint systems for young children traveling on commercial airplanes.
CONTEXT: The US Federal Aviation Administration is planning a new regulation requiring children younger than 2 years to ride in approved child-restraint seats on airplanes. OBJECTIVES: To estimate the annual number of child air crash deaths that might be prevented by the proposed regulation, the threshold proportion of families switching from air to car travel above which the risks of the policy would exceed its benefits, and the cost per death prevented. DESIGN: Risk and economic analyses. RESULTS: Child-restraint seat use could prevent about 0.4 child air crash deaths per year in the United States. Increased deaths as a result of car travel could exceed deaths prevented by restraint seat use if the proportion of families switching from air to car travel exceeded about 5% to 10%. The estimate for this proportion varied with assumptions about trip distance, driver characteristics, and the effectiveness of child-restraint seats but is unlikely to exceed 15%. Assuming no increase in car travel, for each dollar increase in the cost of implementing the regulation per round trip per family, the cost per death prevented would increase by about $6.4 million. CONCLUSIONS: Unless space for young children in restraint seats can be provided at low cost to families, with little or no diversion to automobile travel, a policy requiring restraint seat use could cause a net increase in deaths. Even excluding this possibility, the cost of the proposed policy per death prevented is high.
Accident Prevention↗
Phototherapy use in jaundiced newborns in a large managed care organization: do clinicians adhere to the guideline?
OBJECTIVE: In 1994, the American Academy of Pediatrics (AAP) published a practice guideline with age-specific thresholds for phototherapy for healthy term newborns with hyperbilirubinemia. The purpose of this study was to examine adherence to the guideline in a large managed care organization. METHODS: We conducted a retrospective cross-sectional analysis of linked computerized databases from 11 Northern California Kaiser Permanente Medical Care Program hospitals. Newborn infants included were at least 37 weeks of gestation, had birth weights of at least 2500 g, and were born between January 1, 1995, and December 31, 1996. The primary outcome variable for the study was receipt of phototherapy according to the guideline. Total serum bilirubin (TSB) and infant age in hours at the time of bilirubin measurement were used to classify infants into 3 groups according to the AAP guideline: recommend phototherapy (R), consider phototherapy (C), and did not recommend phototherapy (N). Group R included infants with TSB levels of at least 15 mg/dL before 48 hours of age, at least 18 mg/dL before 72 hours, or at least 20 mg/dL after 72 hours. Group C included infants not in group R, with TSB levels of at least 12 mg/dL before 48 hours, 15 mg/dL before 72 hours, or at least 17 mg/dL after 72 hours. Group N included infants who were in neither group R nor group C and also did not have significant jaundice before 24 hours of age. Phototherapy codes from electronic databases were validated by chart review for a subset of 550 infants. RESULTS: Compared with chart review, phototherapy codes in the database were 94.4% sensitive (95% confidence interval [CI]: 89.1%-97.5%) and 100% specific (95% CI: 99.25%-100%). Among the 47 801 infants eligible, 2.3% received phototherapy. Phototherapy was administered to 54% of 1194 infants in group R (range across hospitals: 27%-77%), 16% of 2245 infants in group C (range: 5%-37%), and 0.2% of 44 362 infants in group N (range: 0.1%-0.6%). The predictors of phototherapy for group R, the group for whom phototherapy was recommended, determined by logistic regression were increasing TSB levels (odds ratio [OR]: 1.6/mg/dL; 95% CI: 1.4-1.7), reaching the AAP threshold at 24 to 47.9 hours of age compared with 48 hours or more (OR: 7.1; 95% CI: 4.3-11.9), gestational age of 37 weeks compared with 38 weeks or more (OR: 1.6; 95% CI: 1.1-2.3), age when phototherapy was first recommended (OR: 0.7/d; 95% CI: 0.6-0.8), and facility of birth (OR: 0.2-2.7). The facility of birth was a strong predictor of phototherapy use in all groups (R, C, and N). CONCLUSIONS: Clinicians provided phototherapy to only 54% of term infants with hyperbilirubinemia for whom it was recommended by the AAP. There is marked interhospital variation in phototherapy use in this large managed care system. Improved adherence to the guideline would require only a slight increase in the total rate of phototherapy use if unnecessary use for infants with lower levels of TSB were simultaneously decreased.
Bilirubin↗
Infants with bilirubin levels of 30 mg/dL or more in a large managed care organization.
OBJECTIVE: To describe the incidence, etiology, treatment, and outcome of newborns with total serum bilirubin (TSB) levels >or=30 mg/dL (513 micro mol/L). DESIGN: Population-based case series. SETTING: Eleven Northern California Kaiser Permanente Medical Care Program hospitals and 1 affiliated hospital. PATIENTS: Eleven infants with TSB levels of >or=30 mg/dL in the first 30 days after birth, identified using computer databases from a cohort of 111,009 infants born 1995-1998. OUTCOME MEASURES: Clinical data from the birth hospitalization, rehospitalization, and outpatient visits in all infants; psychometric testing at age 5 (N = 3), neurologic examinations by child neurologists at age 5 (N = 3), or primary care providers (N = 7; mean age: 2.2 years); Parent Evaluation of Developmental Status (N = 8; mean age: 4.2 years). RESULTS: Maximum TSB levels of the 11 infants ranged from 30.7 to 45.5 mg/dL (525 micro mol/L to 778 micro mol/L; mean: 34.9 mg/dL [597 micro mol/L]). Four were born at 35 to 36 weeks gestation, and 7 were exclusively breastfed. Two had apparent isoimmunization; the etiology for the other 9 remained obscure, although only 4 were tested for glucose-6-phosphate dehydrogenase deficiency and 1 was bacteremic. None had acute neurologic symptoms. All received phototherapy and 5 received exchange transfusions. One infant died of sudden infant death syndrome; there was no kernicterus at autopsy. Two were lost to follow-up but were neurologically normal when last seen for checkups at 18 and 43 months. One child was receiving speech therapy at age 3. There were no significant parental concerns or abnormalities in the other children. CONCLUSIONS: In this setting, TSB levels >or=30 mg/dL were rare and generally unaccompanied by acute symptoms. Although we did not observe serious neurodevelopmental sequelae in this small sample, additional studies are required to quantify the known, significant risk of kernicterus in infants with very high TSB levels.
Adult↗
Neonatal jaundice and urinary tract infections.
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Circumcision, Male↗
Pulse oximetry in bronchiolitis patients.
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Bronchiolitis↗
Urine testing and urinary tract infections in febrile infants seen in office settings: the Pediatric Research in Office Settings' Febrile Infant Study.
OBJECTIVE: To determine the predictors and results of urine testing of young febrile infants seen in office settings. DESIGN: Prospective cohort study. SETTING: Offices of 573 pediatric practitioners from 219 practices in the American Academy of Pediatrics Pediatric Research in Office Settings' research network. SUBJECTS: A total of 3066 infants 3 months or younger with temperatures of 38 degrees C or higher were evaluated and treated according to the judgment of their practitioners. MAIN OUTCOME MEASURES: Urine testing results, early and late urinary tract infections (UTIs), and UTIs with bacteremia. RESULTS: Fifty-four percent of the infants initially had urine tested, of whom 10% had a UTI. The height of the fever was associated with urine testing and a UTI among those tested (adjusted odds ratio per degree Celsius, 2.2 for both). Younger age, ill appearance, and lack of a fever source were associated with urine testing but not with a UTI, whereas lack of circumcision (adjusted odds ratio, 11.6), female sex (adjusted odds ratio, 5.4), and longer duration of fever (adjusted odds ratio, 1.8 for fever lasting > or = 24 hours) were not associated with urine testing but were associated with a UTI. Bacteremia accompanied the UTI in 10% of the patients, including 17% of those younger than 1 month. Among 807 infants not initially tested or treated with antibiotics, only 2 had a subsequent documented UTI; both did well. CONCLUSIONS: Practitioners order urine tests selectively, focusing on younger and more ill-appearing infants and on those without an apparent fever source. Such selective urine testing, with close follow-up, was associated with few late UTIs in this large study. Urine testing should focus particularly on uncircumcised boys, girls, the youngest and sickest infants, and those with persistent fever.
Adult↗
Jaundice noted in the first 24 hours after birth in a managed care organization.
OBJECTIVE: To investigate the significance of jaundice noted in the first 24 hours after birth in a community setting. DESIGN: Supplementary analyses of a nested case-control study. SETTING: Northern California Kaiser Permanente Medical Care Program. PATIENTS: Six hundred thirty-one randomly selected newborns (controls) and 140 cases with total serum bilirubin levels of 25 mg/dL (428 micro mol/L) or higher from a cohort of 105 384 newborns of at least 2000 g birth weight and at least 36 weeks' gestational age, born between January 1, 1995, and December 31, 1998. MAIN OUTCOME MEASURES: Notations of jaundice in the medical record, timing and results of bilirubin testing, use of phototherapy, and development of bilirubin levels of 25 mg/dL or higher. RESULTS: Among the controls, the cumulative probability of a notation of jaundice (corrected for early hospital discharge using survival analysis) was 2.8% within 18 hours and 6.7% within 24 hours. In these newborns, cumulative proportions that had bilirubin levels measured were 38% within 12 hours and 43% within 24 hours of when jaundice was first noted. About 40% of bilirubin levels measured within 24 hours were above the estimated 95th percentile for age. Compared with newborns not noted to be jaundiced on the first day, newborns noted to be jaundiced within 24 hours were more likely to receive phototherapy (18.9% vs 1.7%; relative risk, 10.1; 95% confidence interval, 4.2-24.4) and to develop a bilirubin level of 25 mg/dL or higher (odds ratio, 2.9; 95% confidence interval, 1.6-5.2), but the absolute risk increase for total serum bilirubin levels of 25 mg/dL or higher was 0.2%. CONCLUSION: Jaundice noted in the medical record in the first 24 hours after birth was uncommon and often clinically significant in this setting, but other factors also need to be considered in determining its importance.
Bilirubin↗
Rehospitalization for neonatal dehydration: a nested case-control study.
OBJECTIVES: To determine the incidence of neonatal dehydration leading to rehospitalization, whether clinical and health services data could predict its occurrence, and the outcome of dehydrated infants. METHODS: We employed a retrospective case-control design nested within a cohort of 51 383 newborns weighing 2000 g or more, with a gestational age of 36 weeks or more born at 11 Kaiser Permanente hospitals during 1995 and 1996. Cases were 110 infants who were rehospitalized within 15 days of discharge with dehydration, and who either had 12% or greater weight loss or a serum sodium level of 150 mEq/L or greater. Controls were 402 randomly selected infants. We reviewed subjects' paper medical records and telephoned their families at 24 to 36 months of age to ascertain neurological outcomes. RESULTS: Rehospitalization for dehydration occurred in 2.1 per 1000 live births (95% confidence interval [CI], 1.8-2.6). Among vaginal births, the most important risk factors were being born of a first-time mother (adjusted odds ratio [AOR], 5.5; 95% CI, 3.1-9.6); exclusive breastfeeding (AOR, 11.2; 95% CI, 3.9-32.6); maternal age equal to or older than 35 years (AOR, 3.0; 95% CI, 1.5-6.0); and gestational age younger than 39 weeks (AOR, 2.0, 95% CI, 1.2-3.5). Among cesarean births, having a birth hospitalization length of stay less than 48 hours was associated with dehydration (odds ratio [OR], 14.8; 95% CI, 1.4-154.1). Adherence to the American Academy of Pediatrics follow-up guideline did not decrease risk of readmission. Among surviving infants, 1 of 110 cases and 12 of 400 controls had evidence of possible neurological problems 24 to 36 months after discharge (P =.3). No cases of limb gangrene, amputation, or intracranial infarction occurred. CONCLUSIONS: In this population with good access to medical care, serious sequelae of neonatal dehydration are rare. Interventions to decrease the frequency of neonatal dehydration should focus on first-time mothers and those who breastfeed exclusively.
Birth Weight↗