SEARCH · Search PubMed

Results for “Binomial Distribution”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,657 records · Page 92Linked to original sources

PubMed1996

A statistical approach for analyzing clonogenic survival data.

The assay of colony-forming efficiency is a mainstay in the measurement of cell response in vitro to many physical and chemical agents. Currently, data on colony-forming efficiency can be calculated in a variety of ways. Authors rarely describe in detail the methods used to determine the extent of biological variation within experiments. The use of standard methods of data analysis and presentation would improve interpretation of data and facilitate comparison between laboratories. Here we propose such a method. Binomial and Poisson probability theory were used to increase the accuracy of the estimate of the surviving fraction and to create an objective criterion for determining whether data obtained from serial dilutions of cell numbers used in the assay of colony-forming efficiency should be excluded or included for further analysis. The variability inherent in the calculation of surviving fraction was determined by using Fieller's theorem, a special statistical application for assessing ratios of estimates, to determine the 95% confidence interval. All calculations were done on a simple and commercially available spreadsheet program.

Cell Line↗

PubMed2003

Estimating population size and duplication rates when records cannot be linked.

The capture-recapture approach to estimating the size of a population is a well-studied area of statistics. The number of distinct individuals, N(A) and N(B), on each of two lists, A and B, and the number common to both lists, N(AB), are used to form an estimate of the binomial probability of being on one of the lists, which then allows an estimate to be made of the size of the population. Critical to the method is an accurate count of N(AB). We consider situations in which this count is not available. Such problems arise in a variety of behavioural health contexts in which the need for protection of privacy may prevent sharing identifying information, so it is not possible to specifically match an individual who appears on one list with an individual on the other. Suppose that the birth dates and/or other demographics of individuals on each list are known. We introduce two methods for estimating the duplication rates and the size of the population. Conditioning on the set beta of birth dates of those on list B, N(A) and N(B), the maximum likelihood estimators (MLEs) and their variance are derived. The MLEs are based on the proportion of individuals on list A whose birth dates fall in beta. This approach is particularly useful if list B itself contains duplicates. The second model utilizes the full sample distribution of the birth dates. We generalize this approach to accommodate multiple demographic characteristics. The approaches are applied to the problem of estimating duplication rates and the population size of veterans who have mental illness in Kings County, NY. The data are lists of those receiving service from the Veterans Administration system and from providers funded or certified by the New York State Office of Mental Health.

Adolescent↗

PubMedDate not supplied

A control-conditional test for assessing HIV vaccine efficacy in small sample preclinical studies.

In this paper, we discuss the analysis of data from small sample animal studies intended to evaluate HIV vaccine efficacy. The focus is on the chimpanzee model with HIV infection, a binary outcome, of primary interest. The problem becomes that of testing for a difference in independent binomial proportions, but aspects of the study design call into question the use of standard approaches. As sample sizes may be as small as one or two per group in this context, it is tempting to utilize previous data; such usage, however, carries a high price in terms of additional assumptions. We present a test, referred to as the control-conditional test, which conditions on the control data and assumes (in a manner of Bayesian estimation) only vague prior information. Comparisons are made with Fisher's exact test and an exact unconditional test. The control-conditional test is also generalized to allow the analysis of data from a differential dose design.

AIDS Vaccines↗

PubMed2005

An easy to use method to approximate Poisson confidence limits.

Despite the ever larger choice of softwares and statistical packages allowing fast and accurate computation of binomial and Poisson confidence limits, there is always a need for a simple and reliable formula allowing non-computerized computations. The method proposed in this paper is derived from the Freeman and Tukey's variance stabilizing transformation for a random Poisson variable and adjusted for giving the best fit with the exact Poisson values. Despite its simplicity, allowing its use in any circumstances, this method provides very satisfactory results and a much better fit than classical formula based on the normal approximation, even if a continuity correction is used. It allows computation of Poisson confidence limits both for count or rates and proportions.

Biometry↗

PubMed2004

Resources predicting positive and negative affect during the experience of stress: a study of older Asian Indian immigrants in the United States.

PURPOSE: Using the life stress model of psychological well-being, in this study we examined risks and resources predicting the occurrence of both positive and negative affect among older Asian Indian immigrants who experienced stressful life events. DESIGN AND METHODS: We collected data through a telephone survey of 226 respondents (aged 50 years and older) in the Southeastern United States. We used hierarchical, negative binomial regression analyses to examine correlates of positive and negative affect. RESULTS: Different coping resources influenced positive and negative affect when stressful life events were controlled for. Being female was a common risk factor for poorer positive and increased negative affect. Satisfaction with friendships and a cultural or ethnic identity that is either bicultural or more American were predictive of greater positive affect. Greater religiosity and increased mastery were resources predicting less negative affect. IMPLICATIONS: Cognitive and structural interventions that increase opportunities for social integration, increasing mastery, and addressing spiritual concerns are discussed as ways of coping with stress to improve the well-being of individuals in this immigrant community.

Affect↗

PubMed1996

[Evaluation of the urinalysis of the diabetic patient in primary care].

OBJECTIVE: To study the level of concordance between the reactive strip, urine sediment and culture, and their sensitivity, specificity and predictive values. DESIGN: Crossover study. SETTING: Sotrondio and Laviana Health Centres, Asturias. PARTICIPANTS: Diabetics of 14 or over included in the procedure. MEASUREMENTS AND MAIN RESULTS: A total of 165 analytical samples of blood and urine were studied. The variables were: age, sex, reactive strip (RS) of urine, sediment (S), binomial concordance of reactive strip-sediment (RS-S), culture (C) and metabolic control. The level of concordance between the variables was found through the Kappa index. Very high concordance was obtained in the RS-S and C comparisons (K = 0.49). The analysis of the variable RS-S displayed sensitivity of 66% and specificity of 87%. CONCLUSIONS: Finding a low concordance between reactive strip, sediment and culture suggests their non-exclusive character. The importance of requesting urine sediment instead of the reactive strip for diabetics is indicated. Urine culture could well be included in the diabetic protocol.

Adolescent↗

PubMed2003

Urban-rural differences in suicide trends in young adults: England and Wales, 1981-1998.

Suicide rates amongst young people, particularly males, have increased in many industrialised countries since the 1960s. There is evidence from some countries that the steepest rises have occurred in rural areas. We have investigated whether similar geographical differences in trends in suicide exist in England and Wales by examining patterns of suicide between 1981 and 1998 in relation to rurality. We used two complementary population-based indices of rurality: (1) population density and (2) population potential (a measure of geographic remoteness from large concentrations of population). We used the electoral ward (n=9264, median population aged 15-44: 1829) as the unit of analysis. To assess whether social and economic factors underlie rural-urban differences in trends we used negative binomial regression models to investigate changes in suicide rates between the years for which detailed national census data were available (1981 and 1991). Over the years studied, the most unfavourable trends in suicide in 15-44-year olds generally occurred in areas remote from the main centres of population; this effect was most marked in 15-24-year-old females. Observed patterns were not explained by changes in age- and sex-specific unemployment, socio-economic deprivation or social fragmentation. The mental health of young adults or other factors influencing suicide risk may have deteriorated more in rural than urban areas in recent years. Explanations for these trends require further investigation.

Adolescent↗

PubMed1996

Frequency of pulmonary embolism in patients who have iliofemoral deep vein thrombosis and are treated with once- or twice-daily low-molecular-weight heparin.

PURPOSE: The purpose of this study was to compare the efficacy and safety of treating mobile iliofemoral patients with deep venous thrombosis (DVT) with subcutaneous low-molecular-weight heparin (dalteparin sodium) either 200 IU/kg once-daily (group 1) or 100 IU/kg twice-daily (group 2). METHODS: Consecutive patients with suspected iliofemoral DVT diagnosed by duplex ultrasonography and verified by radionuclide venography were randomized to one of the two low-molecular-weight heparin (LMWH) regimens. Perfusion and when necessary ventilation scans were performed for diagnosis of pulmonary emboli (PE) in all patients immediately after admission and were repeated after approximately 10 days, whereupon oral anticoagulation was started unless contraindicated. Minimal and maximal anti-factor Xa activity was measured after 2 to 3 days of therapy. All patients were kept mobile with compression bandages. The primary end point was reduction in frequency of PE as assessed on the second lung scan. RESULTS: A total of 140 patients with confirmed DVT were randomized, 76 to group 1 and 64 to group 2. The two groups were comparable in their baseline clinical characteristics. In the initial lung scans 36 (47.4%) patients in group 1 and 29 (45.3%) patients in group 2 had objectively verified PE, but only 11 (14.5%) and 8 (12.5%) patients, respectively, had symptoms. After dalteparin treatment PE disappeared in two patients in group 1, but in two other cases new PEs occurred, (NS). In group 2 a resolution of PEs was observed in eight patients, whereas only one new PE could be detected. This change reflects the efficacy of therapy as defined by resolution of existing PEs and by the occurrence of new PEs and is statistically significant according to McNemar's chi-square test with the exact binomial method pair procedure (p < 0.05). Symptomatic PE was reduced from 14.5% to 5.3% in group 1 (96% to CI for the difference, -1.5% to +17.3%) and from 12.5% to 1.6% in group 2 (95% CI for the difference 0.7% to 18%, p < 0.05). There was one single fatal PE, one serious and three minor bleeding episodes in group 1, and one minor bleeding episode in group 2 (95% CI for the difference: -3.6% to +8.1%). CONCLUSIONS: Treatment of ambulant iliofemoral patients with DVT with 100 IU/kg dalteparin twice-daily appears to be moe safe and effective than 200 IU/kg given once-daily. Bed rest is not necessary for treating mobile patients.

Aged↗

PubMed2025

Estimands for Clinical Effectiveness of Risk-Reducing Early Salpingectomy in Women With High Risk of Ovarian Cancer.

IMPORTANCE: Risk-reducing early-salpingectomy (RRES) and delayed oophorectomy (DO) is a novel 2-stage alternative prevention strategy to risk-reducing salpingo-oophorectomy (RRSO) that avoids detrimental consequences of premature menopause. However, direct data on the clinical effectiveness for ovarian cancer (OC) risk reduction are lacking. OBJECTIVE: To explore how to define clinical effectiveness from prospective cohort studies using the estimand framework and sample size requirements. DESIGN, SETTING, AND PARTICIPANTS: In this comparative effectiveness research study, estimand and analysis options were considered to evaluate the clinical effectiveness of RRES with DO by extending the UK PROTECTOR cohort study, a multicenter, prospective, observational, national cohort study (N = 1250 recruited from January 1, 2019, to December 31, 2024) evaluating RRES and DO for OC surgical prevention. Participants were premenopausal women 30 years or older at increased OC risk due to BRCA1/BRCA2 pathogenic variants. Participants could choose RRES, RRSO, or no surgery at entry. Sample size requirements used initial data (eg, age and BRCA1/2 distribution) from PROTECTOR (analysis undertaken from January 1, 2024, to December 31, 2025). MAIN OUTCOMES AND MEASURES: Incidence of OC after (not at) RRES and before or at DO in women with normal histologic analysis findings at surgery. The proportion of cancers prevented was estimated as the completement of the observed (O) to expected (E; assuming no preventive effect of surgery) number of cancers detected (1 - O/E). RESULTS: Initial data were obtained from 889 women in PROTECTOR (overall mean [SD] age, 39 [5] years), with 255 (28.7%) choosing RRSO (mean [SD] age, 42 [4] years), 405 (45.5%) choosing RRES (mean [SD] age, 38 [4] years), and 229 (25.7%) choosing no surgery (mean [SD], 38 [5] years). The preferred estimand outcome was OC incidence after surgery (RRES or RRSO) with a "while on intervention" strategy to account for intercurrent events. The primary target measure was the proportion of cancers prevented for RRES vs no surgery with superiority testing. The secondary target measure was noninferiority of RRES vs RRSO. An estimated 1150 RRES participants with 8 to 10 years of follow-up would provide approximately 92% power to show that 20% or more of cancers are prevented using a 1-sample binomial test of the O:E risk (external reference) at the 5% level under a range of assumptions and at least the same power for a noninferiority margin for the proportion of cancers prevented by RRES of those prevented by RRSO. Estimands based on incidence ratios had an infeasible sample size. CONCLUSIONS AND RELEVANCE: In this comparative effectiveness study of UK BRCA carriers, the estimand differed from other ongoing clinical effectiveness studies of RRES and DO. Advantages include direct use of expected risk at baseline (unknown at design stage), easier interpretation across cohorts than absolute risk differences, and providing a feasible recruitment target for PROTECTOR to evaluate clinical effectiveness.

Humans↗

PubMed2005

Hospitalisation due to sports-related injuries among children and adolescents in New South Wales, Australia: an analysis on socioeconomic and geographic differences.

This population-based epidemiological study aims to investigate the associations between socioeconomic status, geographic location, and sports-related injuries among children and adolescents in New South Wales (NSW), Australia. Data utilised in this study were collected as part of the routine vital health information system via all hospitals in NSW. Included were all patients aged between 5-19 years admitted to a hospital because of sports-related injuries in NSW between 1996 and 2000. The crude age-and-sex-specific hospitalisation rates (/100,000 population-years) by socioeconomic levels and geographic residential locations were calculated. Negative Binomial regression analyses were also performed to examine the associations between socioeconomic status, geographic location and the rate of hospitalisation after adjusting for the age and sex of children and adolescents. The results indicated a significant association between geographic location and hospitalisation due to sports-related injury, after adjusting for age, sex, and socioeconomic status. The risk of hospital admission with sports-related injury among children and adolescents in rural areas was nearly 10% higher than for those in the metropolitan areas (RR=1. 12, 95%C.I.=1.07-1.32)). However, no association between socioeconomic status and hospitalisation with sports-related injury was found. Greater efforts are required in the implementation of safety strategies in research, training, and education for the prevention of sports-related injury in rural areas.

Adolescent↗

PubMed2000

Canonical correlation and chi-square: relationships and interpretation.

A 2 x 2 chi-square can be computed from a phi coefficient, which is the Pearson correlation between two binomial variables. Similarly, chi-square for larger contingency tables can be computed from canonical correlation coefficients. The authors address the following series of issues involving this relationship: (a) how to represent a contingency table in terms of a correlation matrix involving r - 1 row and c - 1 column dummy predictors; (b) how to compute chi-square from canonical correlations solved from this matrix; (c) how to compute loadings for the omitted row and column variables; and (d) the possible interpretive advantage of describing canonical relationships that comprise chi-square, together with some examples. The proposed procedures integrate chi-square analysis of contingency tables with general correlational theory and serve as an introduction to some recent methods of analysis more widely known by sociologists.

Chi-Square Distribution↗

PubMed2006

Effect of month of birth on the risk of suicide.

BACKGROUND: Month of birth as a suicide risk factor has not been adequately explored. The findings of published studies are contradictory and inconclusive. AIMS: To examine the association between suicide and month of birth using suicide data for a 22-year period in England and Wales. The sample size of 26 915 suicides greatly exceeds all previous studies. METHOD: We analysed all suicides (ICD-9 codes E950-959) and deaths from undetermined injury (E980-989) reported between 1979 and 2001 in England and Wales for persons born between 1955 and 1966, using Poisson and negative binomial generalised linear models with seasonal components. RESULTS: Birth rates of people who later kill themselves show disproportionate excess for April, May and June compared with the other months. Overall, we found an increase of 17% in the risk of suicide for people born in the peak month (spring-early summer) compared with those born in the trough month (autumn-early winter); this risk increase was larger for women (29.6%) than for men (13.7%). CONCLUSIONS: The'month of birth'factor in suicide can be interpreted in terms of the foetal origins hypothesis. Our findings might have implications for our understanding of the multifaceted aetiology of suicide and may eventually offer new strategies for research and prevention.

Adult↗

PubMed2002

Ampicillin use in infant fever: a systematic review.

OBJECTIVES: To estimate the prevalence of perinatal Listeria monocytogenes and enterococcal infections in outpatient febrile infants and to evaluate the need to treat with ampicillin. DATA SOURCES: Online bibliographies were searched for articles related to serious bacterial infection and fever in infants. Reference lists from selected and review articles were also examined. STUDY SELECTION: Studies that reported rates and types of bacterial infection in febrile outpatients younger than 3 months were included. Those performed outside North America, lacking results by age, or those that evaluated selected patient populations were excluded. DATA EXTRACTION: Two authors independently reviewed the selected articles for inclusion and abstracted the data. DATA SYNTHESIS: Fourteen studies, evaluating 5247 febrile outpatients, were included. The prevalences of L monocytogenes and enterococcal infections were 7.3 (binomial exact 95% confidence interval [CI], 3.5-13.3), 1.9 (95% CI, 0.6-4.4), and 5.6 (95% CI, 0.7-2.1) per 1000 febrile infants in the first, second, and third months of life, respectively. To cover 1 infant with serious bacterial infection caused by L monocytogenes and enterococcal infections, the numbers of febrile infants who would need ampicillin were estimated as 138 (95% CI, 76-288) in the first month, 527 (95% CI, 226-1621) in the second month, and 178 (95% CI, 50-1469) in the third month. Enterococcal infections occurred in all ages studied; there were no Listeria infections after 30 days of age. CONCLUSION: The empirical use of ampicillin to cover febrile infants for L monocytogenes and enterococcal infections is most justifiable in the first month of life.

Age Distribution↗

PubMed2005

Does race predict stroke readmission? An analysis using the truncated negative binomial model.

BACKGROUND: Although it is known that the risk of first-ever stroke is higher for blacks than for whites, it is unclear what their relative risk is for stroke recurrence. METHODS: Using statewide inpatient data from California, 4,784 blacks and 33,684 whites having one or more stroke admissions during the year 2000 were identified. For blacks and whites, age- and sex-adjusted incidence rates were calculated for the index stroke admission using direct standardization (to the U.S. resident population for the year 2000). Various statistical models for count data were applied, with the best one being used in subsequent age-specific multivariate analyses for the number of stroke admissions. RESULTS: For the index stroke admission, the age- and sex-adjusted incidence rate per 100,000 was 366 (95% CI 355-377) for blacks and 204 (95% CI 202-207) for whites. Those having two or more stroke admissions accounted for less than 20% of the total number of patients. The truncated negative binomial (TNB) model gave the best fit not only to the California data but also to the data reanalyzed from several prior studies done in various countries [i.e., the United Kingdom (Oxfordshire and South London), Switzerland (Lausanne). Australia (Western Australia) and the United States (Nueces County, TX)]. In this study, predictors of stroke readmission changed according to age. For those aged 65-74 years old, blacks showed a higher risk of readmission than whites by 40% after adjustment for patient and hospital factors (RR 1.40, 95% CI 1.19-1.64). This excess risk was lower in other age groups. CONCLUSIONS: These findings suggest that blacks remain a high-risk group after an initial stroke and warrant appropriate intervention. Future studies on recurrent stroke should consider age-specific TNB models.

Adolescent↗

PubMed2006

Jaundice in critical illness: promoting factors of a concealed reality.

OBJECTIVE: In critical illness, liver dysfunction (LD) is associated with a poor outcome independently of other organ dysfunctions. Since strategies to support liver function are not available, a timely and accurate identification of factors promoting LD may lead to prevention or attenuation of its consequences. The aim of this study was to assess risk factors for LD in critically ill patients. DESIGN: Prospective, observational study. SETTING: A multidisciplinary intensive care unit (ICU) of a university hospital. PATIENTS: All patients consecutively admitted over a 6-month period. INTERVENTION: None. MEASUREMENTS AND RESULTS: LD was defined as serum bilirubin levels >or=2 mg/dl and lasting for at least 48 h. Out of 283 patients, 141 matched inclusion criteria. Forty-four patients (31.2%) showed LD (LD group), while 97 (68.8%) were included in control group (C group). A binomial analysis showed that LD occurrence was associated with moderate (odds ratio [OR] 3.11; p=0.04) and severe shock (OR 3.46; p= 0.05), sepsis (OR 3.03; p=0.04), PEEP ventilation (OR 4.25; p=0.006), major surgery (OR 4.03; p=0.03), and gram-negative infections (OR 3.94; p=0.002). In stepwise multivariate analysis, the single independent predictive factors of LD resulted in severe shock (p=0.002), sepsis (p=0.03), PEEP ventilation (p=0.04), and major surgery (p=0.05). CONCLUSIONS: In critically ill patients jaundice is common, and severe shock states, sepsis, mechanical ventilation with PEEP and major surgery are critical risk factors for its onset. Since there is no specific treatment, prompt resuscitation, treatment of sepsis and meticulous supportive care will likely reduce its incidence and severity.

Aged↗

PubMed1996

Repair kinetics in pig epidermis: an analysis based on two separate rates of repair.

Pig skin was irradiated using 90Sr/90Y plaques and the dose-related incidence of induced moist desquamation was determined. The repair of radiation-induced sublethal damage (SLD) was studied by fitting these response data to the generalized LQ equation for incomplete repair using quasilikelihood methods with binomial statistics, and either a Poisson or logistic link to relate the probability of response to the covariates. A Poisson response analysis based on the assumption that SLD was governed by two repair processes gave estimated repair half-times of 0.20 [(95% confidence limits) 0.12, 0.34] and 6.6 [4.3, 10.0] h. The estimates of the short and long repair half-times were significantly different, although there was no significant difference between the results using the Poisson and logistic modes of analyses. The partition coefficient for the longer repair process was 0.5 [0.34, 0.71] indicating that about 33% of SLD-derived lethal damage is associated with the longer repair process in the case of 'complete repair' protocols. However, this proportionation is, in general, protocol dependent for incomplete repair protocols. A chi2 test on the residual deviance showed that the assumption of two repair processes for SLD gave a superior fit to the data than a single repair process at a significance level >99%. The radiation dose to the assumed target cell population depends upon their depth from the skin surface, due to the relatively short range of the electron emission from the 90Sr/90Y plaques. However, further modelling analyses have shown that the estimated repair half-times were independent of the assumed target cell distribution in the skin. This is in contrast with the alpha/beta ratio, where different (clinically significant) estimates can be obtained depending upon the assumed target cell distribution. If the target cells were at 16 micrometer depth from the surface of the skin, the estimated value for the alpha/beta ratio using the biphasic repair model would be 4.6[3.6, 5.6] Gy(Poisson analysis). However, the estimates decrease with the assumed depth (distribution) of the target cells.

Animals↗

PubMed2005

Effects of snowfalls on motor vehicle collisions, injuries, and fatalities.

OBJECTIVES: We estimated the effects of snowfalls on US traffic crash rates between 1975 and 2000. METHODS: We linked all recorded fatal crashes (1.4 million) for the 48 contiguous states from 1975 through 2000 to daily state weather data. For a subsample including 17 states during the 1990s, we also linked all recorded property-damage-only crashes (22.9 million) and nonfatal-injury crashes (13.5 million) to daily weather data. Employing negative binomial regressions, we investigated the effects of snowfall on crash counts. Fixed effects and other controls were included to address potential confounders. RESULTS: Snow days had fewer fatal crashes than dry days (incidence rate ratio [IRR] = 0.93; 95% confidence interval [CI] = 0.90, 0.97), but more nonfatal-injury crashes (IRR = 1.23; 95% CI = 1.18, 1.29) and property-damage-only crashes (IRR=1.45; 95% CI=1.38, 1.52). The first snowy day of the year was substantially more dangerous than other snow days in terms of fatalities (IRR = 1.14; 95% CI=1.08, 1.21), particularly for elderly drivers (IRR=1.34; 95% CI=1.23, 1.50). CONCLUSIONS: The toll of snow-related crashes is substantial. Our results may help estimate the potential benefits of safety innovations currently proposed by meteorology and traffic safety experts.

Accidents, Traffic↗

PubMed2004

Survival rate in congenital diaphragmatic hernia: the experience of the Canadian Neonatal Network.

BACKGROUND/PURPOSE: The Canadian Neonatal Network prospectively collects data from 17 pediatric hospitals accounting for 75% of all neonatal intensive care unit beds nationwide. The purpose of this study was to (1) analyze the database to compare actual survival rates of neonates with congenital diaphragmatic hernia (CDH) to predicted outcomes and (2) assess whether institutional CDH volume was associated with improved survival rate. METHODS: Actual survival rates for CDH patients born during a 22-month period were determined from the registry. Predicted survival rates were calculated using the CDH Study Group logistical regression equation. Actual survival rate was compared with predicted using chi2 analysis. Survival rates were stratified by institutional CDH volume and compared using binomial analysis. P value of less than.05 was deemed statistically significant. RESULTS: Of approximately 20,500 neonatal admissions, 88 cases of CDH were recorded. Seventy-three of 88 (83%) neonates with CDH survived to discharge, whereas the predicted survival rate was 62% (P <.001). Three centers were considered "high-volume" centers with at least 12 CDH diagnoses, and 11 were considered "low-volume" centers. Actual CDH survival was significantly greater at high-versus low-volume centers (90% v 77%; P <.01). CONCLUSIONS: From these prospective data, survival rates of Canadian neonates with CDH are significantly better than predicted by the CDH Study Group equation. Further, high-volume centers in Canada have a significantly higher CDH survival rate than low-volume centers.

Actuarial Analysis↗