Outcomes of Extracorporeal Cardiopulmonary Resuscitation for In-Hospital Cardiac Arrest Among Children With Noncardiac Illness Categories.

OBJECTIVES: The objective of this study was to determine the association of the use of extracorporeal cardiopulmonary resuscitation (ECPR) with survival to hospital discharge in pediatric patients with a noncardiac illness category. A secondary objective was to report on trends in ECPR usage in this population for 20 years. DESIGN: Retrospective multicenter cohort study. SETTING: Hospitals contributing data to the American Heart Association's Get With The Guidelines-Resuscitation registry between 2000 and 2021. PATIENTS: Children (<18 yr) with noncardiac illness category who received greater than or equal to 30 minutes of cardiopulmonary resuscitation (CPR) for in-hospital cardiac arrest. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Propensity score weighting balanced ECPR and conventional CPR (CCPR) groups on hospital and patient characteristics. Multivariable logistic regression incorporating these scores tested the association of ECPR with survival to discharge. A Bayesian logistic regression model estimated the probability of a positive effect from ECPR. A secondary analysis explored temporal trends in ECPR utilization. Of 875 patients, 159 received ECPR and 716 received CCPR. The median age was 1.0 [interquartile range: 0.2-7.0] year. Most patients (597/875; 68%) had a primary diagnosis of respiratory insufficiency. Median CPR duration was 45 [35-63] minutes. ECPR use increased over time ( p < 0.001). We did not identify differences in survival to discharge between the ECPR group (21.4%) and the CCPR group (16.2%) in univariable analysis ( p = 0.13) or propensity-weighted multivariable logistic regression (adjusted odds ratio 1.42 [95% CI, 0.84-2.40; p = 0.19]). The Bayesian model estimated an 85.1% posterior probability of a positive effect of ECPR on survival to discharge. CONCLUSIONS: ECPR usage increased substantially for the last 20 years. We failed to identify a significant association between ECPR and survival to hospital discharge, although a post hoc Bayesian analysis suggested a survival benefit (85% posterior probability).

Social connectedness and adolescent suicide risk.

BACKGROUND: Despite evidence of the importance of interpersonal connectedness to our understanding of suicide risk, relatively little research has examined the protective and buffering effects of connectedness among adolescents. The aims of this study were to determine: (a) whether overall connectedness (composite of family, peer, and school) and specific domains of connectedness were related to a lower likelihood of suicide attempts, and (b) whether these factors buffer the prospective risk of suicide attempt for high-risk subgroups (i.e., recent suicidal ideation and/or lifetime history of suicide attempt, peer victimization, or sexual and gender minority status). METHODS: Participants were 2,897 adolescents (64.7% biological female), ages 12 to 17 (M = 14.6, SD = 1.6), recruited in collaboration with the Pediatric Emergency Care Applied Research Network (PECARN) from 14 emergency departments for the Emergency Department Screen for Teens at Risk for Suicide Study (ED-STARS). Suicide risk and protective factors were assessed at baseline; 3- and 6-month follow-ups were completed (79.5% retention). Multivariable logistic regressions were conducted, adjusting for established suicide risk factors. RESULTS: Higher overall connectedness and, specifically, school connectedness were associated with decreased likelihood of a suicide attempt across 6 months. Overall connectedness and connectedness domains did not function as buffers for future suicide attempts among certain high-risk subgroups. The protective effect of overall connectedness was lower for youth with recent suicidal ideation or a suicide attempt history than for those without this history. Similarly, overall connectedness was protective for youth without peer victimization but not those with this history. Regarding specific domains, family connectedness was protective for youth without recent suicidal ideation or a suicide attempt history and peer connectedness was protective for youth without peer victimization but not youth with these histories. CONCLUSIONS: In this large and geographically diverse sample, overall and school connectedness were related prospectively to lower likelihood of suicide attempts, and connectedness was more protective for youth not in certain high-risk subgroups. Results inform preventive efforts aimed at improving youth connectedness and reducing suicide risk.

Understanding adolescent responses to differently worded suicide attempt questions: results from a large US pediatric sample.

BACKGROUND: Clinical assessments are a primary method for ascertaining suicide risk, yet the language used across measures is inconsistent. The implications of these discrepancies for adolescent responding are unknown, which is troubling as multiple research areas (i.e. on culture, mental health language, and suicide communication) indicate individuals from varying sociodemographic backgrounds may communicate differently regarding mental health concerns. The aims of the current study are to investigate whether a geographically diverse sample of adolescents respond differently to directly and indirectly phrased suicide attempt questions (i.e. directly phrased includes the term 'suicide' and indirectly asks about suicidal behavior without using 'suicide'), and to examine whether sociodemographic factors and history of mental health service usage relate to endorsement differences. METHODS: Participants were N = 5909 adolescents drawn from the Emergency Department Screening for Teens at Risk for Suicide multi-site study. The lifetime suicide attempt was assessed with two items from an adapted version of the Columbia Suicide Severity Rating Scale (C-SSRS; Posner et al., 2008): (1) a directly phrased question asking about 'suicide attempts' and (2) an indirectly phrased question providing the definition of an attempt. RESULTS: An adolescent majority (83.7%) consistently reported no lifetime suicide attempt across items, 10.1% consistently reported one or more lifetime attempts across items, and 6.2% of adolescents responded discordantly to the items. CONCLUSIONS: Multivariable models indicated multiple demographic and mental health service variables significantly predicted discordant responding, with a notable finding being that father/stepfather education level at or below high school education predicted endorsing only the direct question.

Spontaneous aortic thrombosis in neonates: a case report and review of literature.

Neonatal aortic thrombosis is a rare occurrence but can be life-threatening. Most aortic thrombosis in neonates is related to umbilical artery catheters. A case of a neonate with a spontaneous aortic thrombosis is described here along with a comprehensive review of the literature for cases of neonatal aortic thrombosis not related to any intravascular device or procedure. The aetiologies of these spontaneous thromboses and the relevance of hypercoagulable disorders are discussed. The cases were analysed for odds of death by treatment method adjusted for era. The reference treatment method was thrombolysis and anticoagulation. No other treatment modality had significantly lower odds than the reference. Surgery alone had higher odds for death than the reference, but this may be confounded by severity of case. The management recommendations for clinicians encountering neonates with spontaneous neonatal aortic thrombosis are discussed.

Explaining the Immigrant Paradox: The Influence of Acculturation, Enculturation, and Acculturative Stress on Problematic Alcohol Consumption.

The present study explored the Immigrant Paradox (IP), generational differences in problematic alcohol use (alcohol consumption and alcohol-related consequences), among immigrants and US born groups from a number of ethnic minority backgrounds. Our approach separates group differences in problematic alcohol consumption in a counterfactual manner for immigrants and the US born to answer the following counterfactual question: "What would problematic alcohol use levels be for the US born had they been exposed to the alcohol use generation (or protective) processes of immigrants and vice versa?" Multidimensional measures of enculturation (involvement with heritage culture), acculturation (involvement with US culture), acculturative stress, and demographic covariates were used to statistically explain these differences. The sample consisted of Asian American (n = 1,153), Black American (n = 833), and Latinx (n = 1,376) college students from 30 universities. Results indicated significant generational differences in mean levels of alcohol consumption but not alcohol-related consequences. Differences in measured characteristics (endowments) marginally explained differences between immigrants and the US born. On the other hand, endowments significantly explained generational differences and represented an increase in alcohol consumption among immigrants if they had the endowments of the U.S. born. Results are discussed in light of cultural and social factors that contribute to the IP.

Selecting trial centers using a standardized, automated site assessment survey instrument (SASI).

BACKGROUND: To improve the site selection process for clinical trials, we expanded a site survey to include standardized assessments of site commitment time, team experience, feasibility of tight timelines, and local medical community equipoise as factors that might better predict performance. We also collected contact information about institutional research services ahead of site onboarding. AIM: As a first step, we wanted to confirm that an expanded survey could be feasible and generalizable-that asking site teams for more details upfront was acceptable and that the survey could be completed in a reasonable amount of time, despite the assessment length. METHODS: A standardized, two-part Site Assessment Survey Instrument (SASI), examining qualitative components and with multiple contact list sections, was developed using a publicly accessible dashboard and later transferred to a REDCap platform. After multiple rounds of internal testing, the SASI was deployed 11 times for multicenter trials. Follow-up questionnaires were sent to site teams to confirm that an expanded survey instrument is acceptable to the research community and could be completed during a brief work shift. RESULTS: Respondents thought the SASI collected useful and relevant information about their sites (100%). Sites were "comfortable" (90%) supplying detailed information early in the site selection process and 57% completed the SASI in one to two hours. CONCLUSIONS: Coordinating centers and sites found the SASI tool to be acceptable and helpful when collecting data in consideration of multicenter trial site selection.

Prognostic value of patient-reported symptom interference in patients with late-stage lung cancer.

PURPOSE: Patient-reported outcomes (PROs) have been found to be significant predictors of clinical outcomes such as overall survival (OS), but the effect of demographic and clinical factors on the prognostic ability of PROs is less understood. Several PROs derived from the 12-item Short-Form Health Survey (SF-12) and M. D. Anderson Symptom Inventory (MDASI) were investigated for association with OS, with adjustments for other factors, including performance status. METHODS: A retrospective analysis was performed on data from 90 patients with stage IV non-small cell lung cancer. Several baseline PROs were added to a base Cox proportional hazards model to examine the marginal significance and improvement in model fit attributable to the PRO: mean MDASI symptom interference level; mean MDASI symptom severity level for five selected symptoms; SF-12 physical and mental component summaries; and the SF-12 general health item. Bootstrap resampling was used to assess the robustness of the findings. RESULTS: The MDASI mean interference level had a significant effect on OS (p = 0.007) when the model was not adjusted for interactions with other prognostic factors. Further exploration suggested the significance was due to an interaction with performance status (p = 0.001). The MDASI mean symptom severity level and the SF-12 physical component summary, mental component summary, and general health item did not have a significant effect on OS. CONCLUSIONS: Symptom interference adds prognostic information for OS in advanced lung cancer patients with poor performance status, even when demographic and clinical prognostic factors are accounted for.

Intravenous Magnesium: Prompt Use for Asthma in Children Treated in the Emergency Department (IMPACT-ED): Protocol for a Multicenter Pilot Randomized Controlled Trial.

BACKGROUND: Children managed for asthma in an emergency department (ED) may be less likely to be hospitalized if they receive intravenous magnesium sulfate (IVMg). Asthma guidelines recommend IVMg for severely sick children but note a lack of evidence to support this recommendation. All previous trials of IVMg in children with asthma have been too small to answer whether IVMg is effective and safe. A few major questions remain about IVMg. First, it has not been tested early in the course of ED treatment, when the impact on hospitalization would be greatest. Second, the clinical impact of hypotension, a known adverse effect of IVMg, has not been well characterized in previous research. Third, no trials have compared different IVMg doses or serial serum magnesium (total and ionized) concentrations to optimize dosing, so the most effective dose is unknown. A large, conclusive, randomized, placebo-controlled clinical trial of IVMg might be challenging due to the need to enroll and complete study procedures quickly, a lack of understanding of blood pressure changes after IVMg, and a lack of pharmacologic information to guide the optimal doses of IVMg to be tested. Therefore, a pilot study to inform the above gaps is warranted before conducting a definitive trial. OBJECTIVE: The objectives of this study are to (1) demonstrate the feasibility of enrolling children with severe acute asthma in the ED in a multicenter, randomized controlled trial of a placebo, low-dose IVMg, or high-dose IVMg; (2) demonstrate the feasibility of timely delivery of study medication, assessment of blood pressure, and evaluation of adverse events in a standardized protocol; and (3) externally validate a previously constructed pharmacokinetic model and develop a combined pharmacokinetic/pharmacodynamic model for IVMg using magnesium (total and ionized) serum concentrations and their correlation with measures of efficacy and safety. METHODS: This pilot trial tests procedures and gathers information to plan a definitive trial. The pilot trial will enroll as many as 90 children across 3 sites, randomize each child to 1 of 3 study arms, measure blood pressure frequently, and collect 3 blood samples from each participant with corresponding clinical asthma scores. RESULTS: The project was funded by the National Heart, Lung, and Blood Institute (1 R34HL152047-2) in March 2022. Enrollment began in September 2022, and 43 children have been enrolled as of April 2023. We will submit the results for publication in late 2023. CONCLUSIONS: The results of this study will guide the planning of a large, definitive, multicenter trial powered to evaluate if IVMg reduces hospitalization. Blood pressure measurements will inform a monitoring plan for the larger trial, and blood samples and asthma scores will be used to validate pharmacologic models to select the optimal dose of IVMg to be evaluated in the definitive trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT05166811; https://clinicaltrials.gov/ct2/show/NCT05166811. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48302.

A Randomized Clinical Trial Testing Hydroxychloroquine for Reduction of SARS-CoV-2 Viral Shedding and Hospitalization in Early Outpatient COVID-19 Infection.

Early in the COVID-19 pandemic, no effective treatment existed to prevent clinical worsening of COVID-19 among recently diagnosed outpatients. At the University of Utah, Salt Lake City, Utah, we conducted a phase 2 prospective parallel group randomized placebo-controlled trial (NCT04342169) to determine whether hydroxychloroquine given early in disease reduces the duration of SARS-CoV-2 shedding. We enrolled nonhospitalized adults (≥18 years of age) with a recent positive diagnostic test for SARS-CoV-2 (within 72 h of enrollment) and adult household contacts. Participants received either 400 mg hydroxychloroquine by mouth twice daily on day 1 followed by 200 mg by mouth twice daily on days 2 to 5 or oral placebo with the same schedule. We performed SARS-CoV-2 nucleic acid amplification testing (NAAT) on oropharyngeal swabs on days 1 to 14 and 28 and monitored clinical symptomatology, rates of hospitalization, and viral acquisition by adult household contacts. We identified no overall differences in the duration of oropharyngeal carriage of SARS-CoV-2 (hazard ratio of viral shedding time comparing hydroxychloroquine to placebo, 1.21; 95% confidence interval [CI], 0.91, 1.62). Overall, 28-day hospitalization incidence was similar between treatments (4.6% hydroxychloroquine versus 2.7% placebo). No differences were seen in symptom duration, severity, or viral acquisition in household contacts between treatment groups. The study did not reach the prespecified enrollment target, which was likely influenced by a steep decline in COVID-19 incidence corresponding to the initial vaccine rollout in the spring of 2021. Oropharyngeal swabs were self-collected, which may introduce variability in these results. Placebo treatments were not identical to hydroxychloroquine treatments (capsules versus tablets) which may have led to inadvertent participant unblinding. In this group of community adults early in the COVID-19 pandemic, hydroxychloroquine did not significantly alter the natural history of early COVID-19 disease. (This study has been registered at ClinicalTrials.gov under registration no. NCT04342169). IMPORTANCE Early in the COVID-19 pandemic, no effective treatment existed to prevent clinical worsening of COVID-19 among recently diagnosed outpatients. Hydroxychloroquine received attention as a possible early treatment; however, quality prospective studies were lacking. We conducted a clinical trial to test the ability of hydroxychloroquine to prevent clinical worsening of COVID-19.

Delivery of Lung-protective Ventilation for Acute Respiratory Distress Syndrome: A Hybrid Implementation-Effectiveness Trial.

Rationale: Lung-protective ventilation (LPV) improves outcomes for patients with acute respiratory distress syndrome (ARDS), but adherence remains inadequate. Objectives: To measure the process and clinical impacts of implementation of a science-based intervention to improve LPV adherence for patients with ARDS, in part by increased use of clinical decision support (CDS). Methods: We conducted a type III hybrid implementation/effectiveness pilot trial enrolling adult patients with ARDS admitted to three hospitals before and after the launch of a multimodal implementation intervention to increase the use of mechanical ventilation CDS and improve LPV adherence. The primary outcome was patients' percentage of time adherent to low tidal volume (⩽6.5 ml/kg predicted body weight) ventilation (LTVV). Secondary outcomes included adherence to prescribed oxygenation settings, the use of the CDS tool's independent oxygenation and ventilation components, ventilator-free days, and mortality. Analyses employed multivariable regression to compare adjusted pre- versus postintervention outcomes after the exclusion of a postintervention wash-in period. A sensitivity analysis measured process outcomes' level and trend change postintervention using segmented regression. Results: The 446 included patients had a mean age of 60 years, and 43% were female. Demographic and clinical characteristics were similar pre- versus postintervention. The adjusted proportion of adherent time increased postintervention for LTVV (9.2%; 95% confidence interval [CI], 3.8-14.5%) and prescribed oxygenation settings (11.9%; 95% CI, 7.2-16.5%), as did the probability patients spent ⩾90% of ventilated time on LTVV (adjusted odds ratio [aOR] 2.58; 95% CI, 1.64-4.10) and use of ventilation CDS (aOR, 41.3%; 95% CI, 35.9-46.7%) and oxygenation CDS (aOR, 54.3%; 95% CI, 50.9-57.7%). Ventilator-free days (aOR, 1.15; 95% CI, 0.81-1.62) and 28-day mortality (aOR, 0.78; 95% CI, 0.50-1.20) did not change significantly after intervention. Segmented regression analysis supported a causal relationship between the intervention and improved CDS usage but suggested trends before intervention rather than the studied intervention could explain increased LPV adherence after the intervention. Conclusions: In this pilot trial, a multimodal implementation intervention was associated with increased use of ventilator management CDS for patients with ARDS but was not associated with differences in clinical outcomes and may not have independently caused the observed postintervention improvements in LPV adherence. Clinical trial registered with www.clinicaltrials.gov (NCT03984175).

Stratification of risk for emergent intracranial abnormalities in children with headaches: a Pediatric Emergency Care Applied Research Network (PECARN) study protocol.

INTRODUCTION: Headache is a common chief complaint of children presenting to emergency departments (EDs). Approximately 0.5%-1% will have emergent intracranial abnormalities (EIAs) such as brain tumours or strokes. However, more than one-third undergo emergent neuroimaging in the ED, resulting in a large number of children unnecessarily exposed to radiation. The overuse of neuroimaging in children with headaches in the ED is driven by clinician concern for life-threatening EIAs and lack of clarity regarding which clinical characteristics accurately identify children with EIAs. The study objective is to derive and internally validate a stratification model that accurately identifies the risk of EIA in children with headaches based on clinically sensible and reliable variables. METHODS AND ANALYSIS: Prospective cohort study of 28 000 children with headaches presenting to any of 18 EDs in the Pediatric Emergency Care Applied Research Network (PECARN). We include children aged 2-17 years with a chief complaint of headache. We exclude children with a clear non-intracranial alternative diagnosis, fever, neuroimaging within previous year, neurological or developmental condition such that patient history or physical examination may be unreliable, Glasgow Coma Scale score<14, intoxication, known pregnancy, history of intracranial surgery, known structural abnormality of the brain, pre-existing condition predisposing to an intracranial abnormality or intracranial hypertension, head injury within 14 days or not speaking English or Spanish. Clinicians complete a standardised history and physical examination of all eligible patients. Primary outcome is the presence of an EIA as determined by neuroimaging or clinical follow-up. We will use binary recursive partitioning and multiple regression analyses to create and internally validate the risk stratification model. ETHICS AND DISSEMINATION: Ethics approval was obtained for all participating sites from the University of Utah single Institutional Review Board. A waiver of informed consent was granted for collection of ED data. Verbal consent is obtained for follow-up contact. Results will be disseminated through international conferences, peer-reviewed publications, and open-access materials.

Hospitalization Burden and Incidence of Krabbe Disease.

OBJECTIVE: The purpose of our study was to understand the healthcare burden and incidence of Krabbe disease (Krabbe). METHODS: Retrospective analysis of Krabbe patients identified October 1, 2015 through December 31, 2020, ages birth through age 3, evaluated in two national databases. We estimated point prevalence and incidence from year 2016 data. RESULTS: We identified 98 unique Krabbe patients with 736 visits including 260 were inpatient admissions. Total healthcare charges were $51.5 million dollars. We determined a point prevalence of 34 68 Krabbe patients in 2016 ages 0 3 years. This estimates a birth incidence of ~1 in 310,000 live births. Significance: Krabbe disease patients had over $51 million in health care charges and hundreds of hospitalizations. Estimated prevalence and birth incidence is similar to rates observed from newborn screening. Our findings show the tremendous health impacts of Krabbe disease, and provide guidance for efforts in screening and treatment planning.

Evaluation of Posttraumatic Headache Phenotype and Recovery Time After Youth Concussion.

Importance: The Four Corners Youth Consortium was created to fill the gap in our understanding of youth concussion. This study is the first analysis of posttraumatic headache (PTH) phenotype and prognosis in this cohort of concussed youth. Objective: To describe the characteristics of youth with PTH and determine whether the PTH phenotype is associated with outcome. Design, Setting, and Participants: This cohort study examined outcomes from patients in a multi-institutional registry of traumatic brain injury (TBI) clinics from December 2017 to June 2019. Inclusion criteria included being between ages 5 and 18 years at enrollment and presentation within 8 weeks of a mild TBI. Data were analyzed between February 2019 and January 2021. Exposure: Mild TBI with standard care. Main Outcomes and Measures: Time to recovery and headache 3 months after injury; measurement device is the Postconcussion Symptom Inventory (PCSI). PTH with migraine phenotype was defined as moderate-severe headache that is new or significantly worse compared with baseline and associated with nausea and/or photophobia and phonophobia. Results: A total of 612 patients with 625 concussions were enrolled, of whom 387 patients with 395 concussions consented to participate in this study. One hundred nine concussions were excluded (concussions, rather than patients, were the unit of analysis), leaving 281 participants with 286 concussions (168 [58.7%] girls; 195 [75.6%] White; 238 [83.2%] aged 13-18 years). At the initial visit, 133 concussions (46.5%) were from patients experiencing PTH with a migraine phenotype, 57 (20%) were from patients experiencing PTH with a nonmigraine phenotype, and 96 (34%) were from patients with no PTH. Patients with any PTH after concussion were more likely to have prolonged recovery than those without PTH (median [interquartile range], 89 [48-165] days vs 44 [26-96] days; log-rank P < .001). Patients with PTH and a migraine phenotype took significantly longer to recover than those with nonmigraine phenotype (median [interquartile range], 95 [54-195] days vs 70 [46-119] days; log-rank P = .01). Within each phenotype, there was no significant difference between sexes in recovery or PTH at 3 months. Conclusions and Relevance: PTH with a migraine phenotype is associated with persistent symptoms following concussion compared with nonmigraine PTH or no PTH. Given that female sex is associated with higher rates of migraine and migraine PTH, our finding may be one explanation for findings in prior studies that girls are at higher risk for persistent postconcussion symptoms than boys.

Risk and protective factors for suicide among sexual minority youth seeking emergency medical services.

BACKGROUND: Differences in risk and protective factors (e.g., victimization, abuse, social support) have been used to explain elevated rates of suicidal ideation and suicide attempts in sexual minority youth (SMY) relative to heterosexual peers. However, little is known regarding how risk and protective factors may explain suicide risk differences among subgroups of SMY. The aims of this study were to 1) examine differences in prevalence and severity for suicide risk and protective factors among SMY, and 2) explore whether risk and protective factors are differentially associated with suicidal ideation and suicide attempts for SMY subgroups. METHODS: Participants were 6,423 adolescents (ages 12-17) recruited from 14 Emergency Departments across the United States who completed an assessment of suicide risk and protective factors. SMY were 20% of the sample (n = 1,275) and categorized as bisexual (8%), gay/lesbian (2%), mostly straight (5%), or other sexual minority (5%). RESULTS: Bisexual youth had elevated rates of suicidal ideation and attempts, more risk factors (e.g., bullying victimization, depression), and fewer protective factors (e.g., parent-family connectedness, positive affect) relative to mostly straight and other sexual minority youth. Bisexual and gay/lesbian youth only differed in parent-family connectedness (lower among bisexual youth). Depression and parent-family connectedness had weaker associations with suicidal ideation for bisexual youth. LIMITATIONS: Emergency departments were not nationally representative. Study design was cross-sectional, preventing causal inferences. CONCLUSIONS: Interventions seeking to mitigate risk factors and promote protective factors are greatly needed for SMY and may benefit from tailoring to address unique stressors for sexual minority subgroups.

Affinity-based measures of biomarker performance evaluation.

We propose new summary measures of biomarker accuracy which can be used as companions to existing diagnostic accuracy measures. Conceptually, our summary measures are tantamount to the so-called Hellinger affinity and we show that they can be regarded as measures of agreement constructed from similar geometrical principles as Pearson correlation. We develop a covariate-specific version of our summary index, which practitioners can use to assess the discrimination performance of a biomarker, conditionally on the value of a predictor. We devise nonparametric Bayes estimators for the proposed indexes, derive theoretical properties of the corresponding priors, and assess the performance of our methods through a simulation study. The proposed methods are illustrated using data from a prostate cancer diagnosis study.

Longitudinal BMI Growth Curves for Surviving Preterm NICU Infants Based on a Large US Sample.

BACKGROUND: Longitudinal growth curves, based on repeated measurements from the same group of infants, exist for preterm infant weight and length but not for BMI. Our existing BMI (weight divided by length squared) curves are based on cross-sectional birth data obtained from a different group of infants at each gestational age (GA). METHODS: We calculated BMI over time for 68 693 preterm infants between 24 and 36 weeks GA. Stratifying infants by sex, GA at birth, and quintiles based on birth BMI, we created longitudinal median curves using R and validated the resulting curves for empirical fit, proper classification, and normality of z scores. RESULTS: We created 2 sets of BMI growth charts. The first set displays fitted median curves for all 5 percentile groups in each GA group by sex. The second set displays fitted median curves with their corresponding third and 97th percentiles by percentile group, GA, and sex. In the validation analysis, percentage of daily observations below the median curve approximated the expected 50th percentile after the initial 3 days. Unlike the cross-sectional curves, the longitudinal curves reveal the pattern of change corresponding to nadir; postnadir, these curves remained consistently below the cross-sectional curves and varied by GA and sex as expected. The percentage of observations falling below the 50th percentile for cross-sectional curves (revealing optimal growth) was generally much higher than for longitudinal curves (revealing actual growth). CONCLUSIONS: These new longitudinal curves provide clinicians data on how premature infants' body proportionality changes over time.