John M. Tilford

Volume-outcome relationships in pediatric intensive care units.

Context. Pediatric intensive care units (PICUs) have expanded nationally, yet few studies have examined the potential impact of regionalization and no study has demonstrated whether a relationship between patient volume and outcome exists in these units. Documentation of an inverse relationship between volume and outcome has important implications for regionalization of care. Objectives. This study examines relationships between the volume of patients and other unit characteristics on patient outcomes in PICUs. Specifically, we investigate whether an increase in patient volume improves mortality risk and reduces length of stay. Design and Setting. A prospective multicenter cohort design was used with 16 PICUs. All of the units participated in the Pediatric Critical Care Study Group. Participants. Data were collected on 11 106 consecutive admissions to the 16 units over a 12-month period beginning in January 1993. Main Outcome Measures. Risk-adjusted mortality and length of stay were examined in multivariate analyses. The multivariate models used the Pediatric Risk of Mortality score and other clinical measures as independent variables to risk-adjust for illness severity and case-mix differences. Results. The average patient volume across the 16 PICUs was 863 with a standard deviation of 341. We found significant effects of patient volume on both risk-adjusted mortality and patient length of stay. A 100-patient increase in PICU volume decreased risk-adjusted mortality (adjusted odds ratio: .95; 95% confidence interval: .91–.99), and reduced length of stay (incident rate ratio: .98; 95% confidence interval: .975–.985). Other PICU characteristics, such as fellowship training program, university hospital affiliation, number of PICU beds, and childrens hospital affiliation, had no effect on risk-adjusted mortality or patient length of stay. Conclusions. The volume of patients in PICUs is inversely related to risk-adjusted mortality and patient length of stay. A further understanding of this relationship is needed to develop effective regionalization and referral policies for critically ill children.

Relationship of illness severity and length of stay to functional outcomes in the pediatric intensive care unit : A multi-institutional study

Objective: The purpose of this study was to establish relationships between illness severity, length of stay, and functional outcomes in the pediatric intensive care unit (PICU) by using multi‐institutional data. We hypothesized that a positive relationship exists between functional outcome scores, severity of illness, and length of stay. Design: The study used a prospective multicentered inception cohort design. Setting: The study was conducted in 16 PICUs across the United States that were member institutions of the Pediatric Critical Care Study Group of the Society of Critical Care Medicine. Patients: In total, 11,106 patients were assessed, representing all admissions to these intensive care units for 12 consecutive months. Measurements: Functional outcomes were measured by the Pediatric Overall Performance Category (POPC) and Pediatric Cerebral Performance Category (PCPC) scales. Both scales were assessed at baseline and discharge from the PICU. Delta scores were formed by subtracting baseline scores from discharge scores. Other measurements included admission Pediatric Risk of Mortality scores, age, operative status, length of stay in the PICU, and diagnoses. Interrater reliability was assessed by using a set of ten standardized cases on two occasions 6 months apart. Main Results: Baseline, discharge, and delta POPC and PCPC outcome scores were associated with length of stay in the PICU and with predicted risk of mortality (p < .01). Incorporation of baseline functional status in multivariate length of stay analyses improved measured fit. Mild baseline cerebral deficits in children were associated with 18% longer PICU stays after controlling for other patient and institutional characteristics. Moderate and severe baseline deficits for both the POPC and PCPC score predict increased length of stay of between 30% and 40%. On the standardized cases, interrater consensus was achieved on 82% of scores with agreement to within one neighboring class for 99.7% of scores. Conclusions: These data establish current relationships for the POPC and PCPC outcome scales based on multi‐institutional data. The reported relationships can be used as reference values for evaluating clinical programs or for clinical outcomes research.

Variation in therapy and outcome for pediatric head trauma patients.

ObjectiveThis study was undertaken to examine variation in therapies and outcome for pediatric head trauma patients by patient characteristics and by pediatric intensive care unit. Specifically, the study was designed to examine severity of illness on admission to the pediatric intensive care unit, the therapies used during the pediatric intensive care unit stay, and patient outcomes. Data Sources and Setting Consecutive admissions from three pediatric intensive care units were recorded prospectively (n = 5,749). For this study, all patients with an admitting diagnosis of head trauma were included (n = 477). Data collection occurred during an 18-month period beginning in June 1996. All of the pediatric intensive care units were located in children’s hospitals, had residency and fellowship training programs, and were headed by a pediatric intensivist. MethodsAdmission severity was measured as the worst recorded physiological derangement during the period ≤6 hrs before pediatric intensive care unit admission. Therapies and resource use were based on the Therapeutic Intervention Scoring System with adaptations for pediatrics. The use of intracranial pressure monitoring was recorded on admission to the unit (within 1 hr) and at any time during the pediatric intensive care unit stay. Outcomes were measured at the time of pediatric intensive care unit discharge by the Pediatric Overall Performance Category scale. Risk factors for mortality were examined by using bivariate analyses with significant predictors as candidate variables in a logistic regression to predict expected mortality. Intracranial pressure monitoring and other therapies were added to the mortality prediction model to test for protective effects. Finally, race and insurance status were added to the model to test for differences in the quality of care. ResultsThe overall mortality rate for the entire sample was 7.8%. Mortality rates for children ≤1 yr old were significantly higher than for children >1 yr old (16.1% vs. 6.1%;p = .002). Comparisons by insurance status indicated that observed mortality rates were highest for self-paying patients. However, patient characteristics were not associated with use of therapies or standardized mortality rates after adjustment for patient severity. There was significant variation in the use of paralytic agents, seizure medications, induced hypothermia, and intracranial pressure monitoring on admission across the three pediatric intensive care units. In multivariate models, only the use of seizure medications was associated significantly with reduced mortality risk (odds ratio = 0.17; 95% confidence interval = 0.04–0.70;p = .014). ConclusionsTherapies and outcomes vary across pediatric intensive care units that care for children with head injuries. Increased use of seizure medications may be warranted based on data from this observational study. Large randomized controlled trials of seizure prophylaxis in children with head injury have not been conducted and are needed to confirm the findings presented here.

Trends in Hospitalizations Associated With Pediatric Traumatic Brain Injuries

OBJECTIVES. The goals were to describe trends in pediatric traumatic brain injury hospitalizations in the United States and to provide national benchmarks for state and regional comparisons. METHODS. Analysis of existing data (1991–2005) from the Nationwide Inpatient Sample, the largest longitudinal, all-payer, inpatient care database in the United States, was performed. Children 0 to 19 years of age were included. Annual rates of traumatic brain injury-related hospitalizations, stratified according to age, gender, severity of traumatic brain injury, and outcome, were determined. RESULTS. From 1991 to 2005, the estimated annual incidence rate of pediatric hospitalizations associated with traumatic brain injury decreased 39%, from 119.4 to 72.7 hospitalizations per 100 000. The rates decreased for all age groups and for both boys and girls, although the rate for boys remained consistently higher at each time point. Fatal hospitalization rates decreased from 3.5 deaths per 100 000 in 1991–1993 to 2.8 deaths per 100 000 in 2003–2005. The rate of mild traumatic brain injury hospitalizations accounted for most of the overall decrease, whereas nonfatal hospitalization rates for moderate and severe traumatic brain injuries remained relatively unchanged. CONCLUSIONS. Although pediatric hospitalization rates for mild traumatic brain injuries have decreased over the past 15 years, rates for moderate and severe traumatic brain injuries are relatively unchanged. Our study provides national estimates of pediatric traumatic brain injury hospitalizations that can be used as benchmarks to increase injury prevention effectiveness through targeting of effective strategies.

Hospitalizations for critically ill children with traumatic brain injuries: A longitudinal analysis*

Objective:This study examines the incidence, utilization of procedures, and outcomes for critically ill children hospitalized with traumatic brain injury over the period 1988–1999 to describe the benefits of improved treatment. Design:Retrospective analysis of hospital discharges was conducted using data from the Health Care Cost and Utilization Project Nationwide Inpatient Sample that approximates a 20% sample of U.S. acute care hospitals. Setting:Hospital inpatient stays from all types of U.S. community hospitals. Participants:The study sample included all children aged 0–21 with a primary or secondary ICD-9-CM diagnosis code for traumatic brain injury and a procedure code for either endotracheal intubation or mechanical ventilation. Interventions:None. Measurements and Main Results:Deaths occurring during hospitalization were used to calculate mortality rates. Use of intracranial pressure monitoring and surgical openings of the skull were investigated as markers for the aggressiveness of treatment. Patients were further classified by insurance status, household income, and hospital characteristics. Over the 12-yr study period, mortality rates decreased 8 percentage points whereas utilization of intracranial pressure monitoring increased by 11 percentage points. The trend toward more aggressive management of traumatic brain injury corresponded with improved hospital outcomes over time. Lack of insurance was associated with vastly worse outcomes. An estimated 6,437 children survived their traumatic brain injury hospitalization because of improved treatment, and 1,418 children died because of increased mortality risk associated with being uninsured. Improved treatment was valued at approximately

Differences in pediatric ICU mortality risk over time

17 billion, whereas acute care hospitalization costs increased by

Health state preference scores of children with spina bifida and their caregivers

1.5 billion (in constant 2000 dollars). Increased mortality in uninsured children was associated with a

PREFERENCE-BASED HEALTH-RELATED QUALITY OF LIFE OUTCOMES IN CHILDREN WITH AUTISM SPECTRUM DISORDERS: A COMPARISON OF GENERIC INSTRUMENTS

3.76 billion loss in economic benefits. Conclusions:More aggressive management of pediatric traumatic brain injury appears to have contributed to reduced mortality rates over time and saved thousands of lives. Additional lives could be saved if mortality rates could be equalized between insured and uninsured children.

Hospital survival of very-low-birth-weight neonates from 1977 to 2000.

OBJECTIVES To compare pediatric intensive care unit (ICU) mortality risk using models from two distinct time periods; and to discuss the implications of changing mortality risk for severity systems and quality-of-care assessment. DATA SOURCES AND SETTING Consecutive admissions (n = 10,833) from 16 pediatric ICUs across the United States that participate in the Pediatric Critical Care Study Group were recorded prospectively. Data collection occurred during a 12-mo period beginning in January 1993. METHODS Data collection for the development and validation of the original Pediatric Risk of Mortality (PRISM) score occurred from 1980 to 1985. The original PRISM coefficients were used to calculate mortality probabilities in the current data set. Updated estimates of mortality probabilities were calculated, using coefficients from a logistic regression analysis using the original PRISM variable set. Quality-of-care tests were performed using standardized mortality ratios. RESULTS Risk of mortality from pediatric ICU admission improved considerably between the two periods. Overall, the reduction in mortality risk averaged 15% (p < .001). Analysis of mortality risk by age indicated a large improvement for younger infants. The mortality risk for infants <1 mo improved by 39% (p < .001). Mortality risk improved by 28% (p < .001) for infants between 1 and 12 mos. Analysis of mortality risk by principal diagnosis indicated substantial improvement in respiratory diseases, including respiratory diseases developing in the perinatal period. The mortality risk for respiratory diseases improved by 45% (p < .001). The improvement in mortality risk substantially deteriorated the calibration of the original PRISM severity system (p < .001). As a result of changing mortality risk, the standardized mortality ratios across the 16 pediatric ICUs demonstrated substantial disparities, depending on the choice of models. CONCLUSIONS This study documents differences in pediatric ICU risk of mortality over time that are consistent with a general improvement in the quality of pediatric intensive care. Despite continued widespread use of the original PRISM, recent improvements in pediatric ICU quality of care have negated its usefulness for many intended applications, including quality-of-care assessment.

Hospitalizations of Newborns With Folate-Sensitive Birth Defects Before and After Fortification of Foods With Folic Acid

Cost-effectiveness evaluations of interventions to prevent or treat spin a bifida require quality of life information measured as preference scores. Preference scores of care givers also may be relevant. This study tested whether the preference scores of children with spin a bifida and their care givers would decrease as disability in the child increased. Families of children aged 0–17 with spin a bifida (N=98) were iden ti fied using a birth defect surveillance sys tem in the state of Arkansas. Primary care giv ers of chil dren with spin a bifida identified other families with an unaffected child (N=49). Preference scores for child health states were determined using the Health Utilities Index – Mark 2 (HUI2). Care giver preference scores were determined using the Quality of Well-Being (QWB) scale. Children with spin a bifida were categorized into three disability levels according to the location of the child’s lesion. Mean preference scores declined for both affected children and the primary care giver as disability in the child increased. In multivariate analysis, the preference score of the child was a significant and positive predictor of the primary care giver’s preference score. A more modest association was found for care giver health preference scores by lesion location. The findings can inform cost-effec tiveness evaluations of interventions to treat or prevent spin a bifida.