Nucleated Red Blood Cells Are Predictive of In-Hospital Mortality for Pediatric Patients

PURPOSE

We sought to establish whether nucleated red blood cells (NRBCs) are predictive of disposition, morbidity, and mortality for pediatric patients presenting to the emergency department (ED).

METHODS

A single-center retrospective cohort study examining all ED encounters from patients aged younger than 19 years between January 2016 and March 2020, during which a complete blood count was obtained. Univariate analysis and multivariable logistic regression were used to test the presence of NRBCs as an independent predictor of patient-related outcomes.

RESULTS

The prevalence of NRBCs was 8.9% (4195/46,991 patient encounters). Patient with NRBCs were younger (median age 4.58 vs 8.23 years; P < 0.001). Those with NRBCs had higher rates of in-hospital mortality (30/2465 [1.22%] vs 65/21,741 [0.30%]; P < 0.001), sepsis (19% vs 12%; P < 0.001), shock (7% vs 4%; P < 0.001), and cardiopulmonary resuscitation (CPR) (0.62% vs 0.09%; P < 0.001). They were more likely to be admitted (59% vs 51%; P < 0.001), have longer median hospital length of stay {1.3 (interquartile range [IQR], 0.22-4.14) vs 0.8 days (IQR, 0.23-2.64); P < 0.001}, and median intensive care unit (ICU) length of stay (3.9 [IQR, 1.87-8.72] vs 2.6 days [IQR, 1.27-5.83]; P < 0.001). Multivariable regression revealed presence of NRBCs as an independent predictor for in-hospital mortality (adjusted odds ratio [aOR], 2.21; 95% confidence interval [CI], 1.38-3.53; P < 0.001), ICU admission (aOR, 1.30; 95% CI, 1.11-1.51; P < 0.001), CPR (aOR, 3.83; 95% CI, 2.33-6.30; P < 0.001), and 30-day return to the ED (aOR, 1.15; 95% CI, 1.15-1.26; P < 0.001).

CONCLUSIONS

The presence of NRBCs is an independent predictor for mortality, including in-hospital mortality, ICU admission, CPR, and readmission within 30 days for children presenting to the ED.

Using extended reality (XR) for medical training and real-time clinical support during deep space missions

Medical events can affect space crew health and compromise the success of deep space missions. To successfully manage such events, crew members must be sufficiently prepared to manage certain medical conditions for which they are not technically trained. Extended Reality (XR) can provide an immersive, realistic user experience that, when integrated with augmented clinical tools (ACT), can improve training outcomes and provide real-time guidance during non-routine tasks, diagnostic, and therapeutic procedures. The goal of this study was to develop a framework to guide XR platform development using astronaut medical training and guidance as the domain for illustration. We conducted a mixed-methods study-using video conference meetings (45 subject-matter experts), Delphi panel surveys, and a web-based card sorting application-to develop a standard taxonomy of essential XR capabilities. We augmented this by identifying additional models and taxonomies from related fields. Together, this "taxonomy of taxonomies," and the essential XR capabilities identified, serve as an initial framework to structure the development of XR-based medical training and guidance for use during deep space exploration missions. We provide a schematic approach, illustrated with a use case, for how this framework and materials generated through this study might be employed.

Assessment of the Non-Technical Skills for Surgeons (NOTSS) framework in the USA

Background

Surgeons' non-technical skills are important for patient safety. The Non-Technical Skills for Surgeons assessment tool was developed in the UK and recently adapted to the US surgical context (NOTSS-US). The aim of this study was to evaluate the reliability and distribution of non-technical skill ratings given by attending (consultant) surgeons who underwent brief online training.

Methods

Attending surgeons across six specialties at a large US academic medical centre underwent a 10-min online training, then rated 60-s standardized videos of simulated operations. Intraclass correlation coefficient (ICC), and mean(s.d.) values for NOTSS-US ratings were determined for each non-technical skill category (score range 1–5, where 1 indicates poor, 3 average and 5 excellent) and for total NOTSS-US score (range 4–20; sum of 4 category scores). Outcomes were adjusted for rater characteristics including sex, specialty and clinical experience.

Results

A total of 8889 ratings were submitted by 81 surgeon raters on 30 simulated intraoperative videos. The mean(s.d.) total NOTSS-US score for all videos was 9·5(4·8) of 20. The within-video ICC for total NOTSS-US score was 0·64 (95 per cent c.i. 0·57 to 0·70). For individual non-technical skill categories, the ICC was highest for social skills (communication/teamwork: 0·63, 95 per cent c.i. 0·56 to 0·71; leadership: 0·64, 0·55 to 0·72) and lowest for cognitive skills (situation awareness: 0·54, 0·45 to 0·62; decision-making: 0·50, 0·41 to 0·59). Women gave higher total NOTSS-US scores than men (adjusted mean difference 0·93, 95 per cent c.i. 0·44 to 1·43; P = 0·001).

Conclusion

After brief online training, the inter-rater reliability of the NOTSS-US assessment tool achieved moderate strength among trained surgeons rating simulated intraoperative videos.

Variation in global uptake of the Surgical Safety Checklist

Background

The Surgical Safety Checklist (SSC) is a patient safety tool shown to reduce mortality and to improve teamwork and adherence with perioperative safety practices. The results of the original pilot work were published 10 years ago. This study aimed to determine the contemporary prevalence and predictors of SSC use globally.

Methods

Pooled data from the GlobalSurg and Surgical Outcomes studies were analysed to describe SSC use in 2014–2016. The primary exposure was the Human Development Index (HDI) of the reporting country, and the primary outcome was reported SSC use. A generalized estimating equation, clustering by facility, was used to determine differences in SSC use by patient, facility and national characteristics.

Results

A total of 85 957 patients from 1464 facilities in 94 countries were included. On average, facilities used the SSC in 75·4 per cent of operations. Compared with very high HDI, SSC use was less in low HDI countries (odds ratio (OR) 0·08, 95 per cent c.i. 0·05 to 0·12). The SSC was used less in urgent compared with elective operations in low HDI countries (OR 0·68, 0·53 to 0·86), but used equally for urgent and elective operations in very high HDI countries (OR 0·96, 0·87 to 1·06). SSC use was lower for obstetrics and gynaecology versus abdominal surgery (OR 0·91, 0·85 to 0·98) and where the common or official language was not one of the WHO official languages (OR 0·30, 0·23 to 0·39).

Conclusion

Worldwide, SSC use is generally high, but significant variability exists. Implementation and dissemination strategies must be developed to address this variability.

Effect of the Serious Illness Care Program on Health Care Utilization at the End of Life for Patients with Cancer

Objectives: To determine the effect of the Serious Illness Care Program on health care utilization at the end of life in oncology. Design: Analysis of the secondary outcome of health care utilization as part of a cluster-randomized clinical trial that ran from 2012 to 2016. Clinicians in the intervention group received training, coaching, and system supports to have discussions with patients using a Serious Illness Conversation Guide (SICG); clinicians in the control arm followed usual care. Setting/Subject: Patients with advanced cancer who died within two years of enrollment at the Dana-Farber Cancer Institute. Measurement: Health care utilization was abstracted from the electronic medical record using the National Quality Forum (NQF)-endorsed indicators of aggressive cancer care at the end of life and scored from 0 to 6 (one point for each aggressive indicator); t tests and chi-square tests were used to determine differences between intervention and control patients. Results: The charts of 159 patients who died were reviewed. Neither the main outcome of mean number of aggressive indicators (0.9 vs. 0.9, p = 0.84) nor the proportion of patients with any aggressive care (49% intervention [95% CI: 40-57] vs. 54% control [95% CI: 42-67]) differed between patients in the intervention and control groups. Conclusion: In this analysis of a secondary outcome from a randomized clinical trial of the Serious Illness Care Program, intervention and control patients had similar end-of-life health care utilization as measured by the mean number of NQF-endorsed indicators. Future research efforts should focus on studying the strategies by which communication about patients' prognosis, values, and goals leads to personalized care plans.

Variation in expenditure for common, high cost surgical procedures in a working age population: implications for reimbursement reform

BACKGROUND

In the move toward value-based care, bundled payments are believed to reduce waste and improve coordination. Some commercial insurers have addressed this through the use of bundled payment, the provision of one fee for all care associated with a given index procedure. This system was pioneered by Medicare, using a population generally over 65 years of age, and despite its adoption by mainstream insurers, little is known of bundled payments' ability to reduce variation or cost in a working-age population. This study uses a universally-insured, nationally-representative population of adults aged 18-65 to examine the effect of bundled payments for five high-cost surgical procedures which are known to vary widely in Medicare reimbursement: hip replacement, knee replacement, coronary artery bypass grafting (CABG), lumbar spinal fusion, and colectomy.

METHODS

Five procedures conducted on adults aged 18-65 were identified from the TRICARE database from 2011 to 2014. A 90-day period from index procedure was used to determine episodes of associated post-acute care. Data was sorted by Zip code into hospital referral regions (HRR). Payments were determined from TRICARE reimbursement records, they were subsequently price standardized and adjusted for patient and surgical characteristics. Variation was assessed by stratifying the HRR into quintiles by spending for each index procedure.

RESULTS

After adjusting for case mix, significant inter-quintile variation was observed for all procedures, with knee replacement showing the greatest variation in both index surgery (107%) and total cost of care (75%). Readmission was a driver of variation for colectomy and CABG, with absolute cost variation of $17,257 and $13,289 respectively. Other post-acute care spending was low overall (≤$1606, for CABG).

CONCLUSIONS

This study demonstrates significant regional variation in total spending for these procedures, but much lower spending for post-acute care than previously demonstrated by similar procedures in Medicare. Targeting post-acute care spending, a common approach taken by providers in bundled payment arrangements with Medicare, may be less fruitful in working aged populations.

Can we improve the quality of documented end-of-life conversations using a structured, multicomponent intervention?

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Background: Conversations about serious illness care goals are often inadequate and fail to address key elements of high-quality discussions. Methods: As part of a cluster-randomized trial of a multi-component communication intervention, we conducted a retrospective chart review of 147 deceased oncology patients to assess frequency and timing of documentation of end-of-life (EOL) conversations; charts of a subset of 20 intervention and 20 matched control patients underwent detailed review to assess quality. A systematically developed abstraction tool was used by two blinded researchers. The tool contained 25 elements reflecting four EOL conversation domains: goals/values, illness understanding/prognosis, EOL care planning, life-sustaining treatments. Results: Of 153 intervention patients, 44.4% died (n = 68); of 161 controls, 49.1% died (n = 79). Significantly more intervention patients than controls (92.7% vs 74.7%, p = 0.006) had at least 1 documented EOL discussion before death; intervention conversations occurred 3 months earlier (median 147 days vs 62 days, p = 0.003). 59.4% of intervention conversations were documented in a retrievable EHR location compared to 10.2% of controls (p = 0.001). In the detailed review, 85% (n = 17) of intervention and 40% (n = 8) of controls had at least 1 documented discussion about values/goals (p = 0.0001), with an average of 3.6 of 8 elements (0.7 of 8 for controls) (p = 0.0003). 85% percent (n = 17) of intervention and 30% (n = 6) of controls had at least 1 documented discussion about prognosis (p = 0.0014), with an average of 2.5 of 7 elements (0.5 of 7 for controls) (p = 0.001). 85% of intervention (n = 17) and 55% of controls (n = 11) had at least 1 documented discussion about EOL planning (p = 0.009). 55% of intervention and 30% of controls had at least 1 documented discussion about life-sustaining treatments (p = 0.20). Conclusions: The intervention resulted in more, earlier and better documentation of serious illness care goals. Across 3 of 4 domains of quality, intervention patients had more detailed information about their EOL care preferences, demonstrating that the intervention results in more patient-centered, comprehensive discussions. Clinical trial information: NCT01786811.

The utility of the surprise question in identifying patients most at risk of death

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Background: Understanding the cancer patient’s prognosis in all illness phases is important. Evidence suggests that the “Surprise Question” (SQ) -- “Would you be surprised if this patient died within the next year?” -- may be useful in identifying those most at risk of death, but prior studies are limited by the relatively small number of patients and clinicians included. Methods: From July 2012 to October 2014, oncology clinicians at Dana-Farber Cancer Institute were invited to enroll in a randomized controlled trial on the impact of a structured intervention to improve conversations about end-of-life goals -- the Serious Illness Care Program. The SQ was asked about each patient seen by the enrolled clinician. We used a weighted propensity score approach to calculate adjusted proportions of survival at 6 months and 1 year, clustering by SQ clinician. To determine which variable was most predictive of death, we fit a multivariable Cox model, and found the variable that led to the largest increase in the Cox-regression goodness-of-fit c-statistic. Results: 81 oncology clinicians (59 oncologists, 18 nurse practitioners, and 4 physician assistants) enrolled in the study and we had complete data on 4617 patients: 3821 (83%) for whom the clinician answered “Yes” to the SQ and 796 (17%) for whom the answer was “No.” Propensity-adjusted 1-year survival for “Yes” patients was 93% (95%CI 91-96%) compared to 53% (95%CI 46-60%) for the “No” patients (p < 0.0001). The SQ was more predictive of patient death than type of cancer, age, cancer stage, or time since diagnosis. Sensitivity of the “No” response was 59% (95%CI 49-68%) and specificity was 90% (95%CI 86-93%). Positive predictive value was 49% (95%CI 45-54%) and negative predictive value was 93% (95%CI 90-95%). Conclusions: The Surprise Question identifies cancer-center patients at high risk of death within one year better than clinical variables such as cancer type, stage, patient age, or time since diagnosis.

The Surgical Safety Checklist and Teamwork Coaching Tools: a study of inter-rater reliability

OBJECTIVE

To assess the inter-rater reliability (IRR) of two novel observation tools for measuring surgical safety checklist performance and teamwork.

SUMMARY BACKGROUND

Data surgical safety checklists can promote adherence to standards of care and improve teamwork in the operating room. Their use has been associated with reductions in mortality and other postoperative complications. However, checklist effectiveness depends on how well they are performed.

METHODS

Authors from the Safe Surgery 2015 initiative developed a pair of novel observation tools through literature review, expert consultation and end-user testing. In one South Carolina hospital participating in the initiative, two observers jointly attended 50 surgical cases and independently rated surgical teams using both tools. We used descriptive statistics to measure checklist performance and teamwork at the hospital. We assessed IRR by measuring percent agreement, Cohen's κ, and weighted κ scores.

RESULTS

The overall percent agreement and κ between the two observers was 93% and 0.74 (95% CI 0.66 to 0.79), respectively, for the Checklist Coaching Tool and 86% and 0.84 (95% CI 0.77 to 0.90) for the Surgical Teamwork Tool. Percent agreement for individual sections of both tools was 79% or higher. Additionally, κ scores for six of eight sections on the Checklist Coaching Tool and for two of five domains on the Surgical Teamwork Tool achieved the desired 0.7 threshold. However, teamwork scores were high and variation was limited. There were no significant changes in the percent agreement or κ scores between the first 10 and last 10 cases observed.

CONCLUSIONS

Both tools demonstrated substantial IRR and required limited training to use. These instruments may be used to observe checklist performance and teamwork in the operating room. However, further refinement and calibration of observer expectations, particularly in rating teamwork, could improve the utility of the tools.

The association of hospital quality ratings with adverse events

OBJECTIVE

To understand how patient-reported quality is related to adverse events (AEs).

DESIGN

Random sample telephone survey.

SETTING

Sixteen acute care Massachusetts hospitals.

PARTICIPANTS

Two thousand and five hundred and eight-two of 4163 (62% response rate) eligible adult patients.

MAIN OUTCOME MEASURES

Patients hospitalized from 1 April 2003 to 1 October 2003 provided global quality ratings and whether they experienced AEs. Service recovery, defined as efforts by a service provider to return customers to a state of satisfaction after a lapse in service, was operationalized as high participation in one's care, timely discharge and disclosure of the circumstances of an AE.

RESULTS

Of respondents, 82% rated the quality as high and 23% reported one or more AEs. Patients with no AEs gave higher quality ratings (85 vs. 77 or 62% for patients with 1 or 2+ AEs, respectively, P < 0.001). Patients were more likely to rate the quality high if they reported high participation (86 vs. 53%), or felt discharge timing was just right (85 vs. 64%); for those with AEs, ratings were higher among those reporting disclosure (82 vs. 66%) (all P < 0.01). In adjusted analyses, patients with AEs experiencing all three service recovery components rated their quality higher (86 vs. 68%, P < 0.01).

CONCLUSIONS

Patients with AEs rate the quality of care lower than others. However, patients with AEs who experienced 'service recovery' as we defined it rated their quality of care at levels similar to those who did not experience AEs. Hospitals seeking to improve quality ratings might consider efforts to ensure patient safety and to address AEs in a transparent and responsive way.

Preventing cardiac remodeling: the combination of cell-based therapy and cardiac support therapy preserves left ventricular function in rodent model of myocardial ischemia

OBJECTIVE

Cellular and mechanical treatment to prevent heart failure each holds therapeutic promise but together have not been reported yet. The goal of the present study was to determine whether combining a cardiac support device with cell-based therapy could prevent adverse left ventricular remodeling, more than either therapy alone.

METHODS

The present study was completed in 2 parts. In the first part, mesenchymal stem cells were isolated from rodent femurs and seeded on a collagen-based scaffold. In the second part, myocardial infarction was induced in 60 rats. The 24 survivors were randomly assigned to 1 of 4 groups: control, stem cell therapy, cardiac support device, and a combination of stem cell therapy and cardiac support device. Left ventricular function was measured with biweekly echocardiography, followed by end-of-life histopathologic analysis at 6 weeks.

RESULTS

After myocardial infarction and treatment intervention, the ejection fraction remained preserved (74.9-80.2%) in the combination group at an early point (2 weeks) compared with the control group (66.2-82.8%). By 6 weeks, the combination therapy group had a significantly greater fractional area of change compared with the control group (69.2% ± 6.7% and 49.5% ± 6.1% respectively, P = .03). Also, at 6 weeks, the left ventricular wall thickness was greater in the combination group than in the stem cell therapy alone group (1.79 ± 0.11 and 1.33 ± 0.13, respectively, P = .02).

CONCLUSIONS

Combining a cardiac support device with stem cell therapy preserves left ventricular function after myocardial infarction, more than either therapy alone. Furthermore, stem cell delivery using a cardiac support device is a novel delivery approach for cell-based therapies.

Utilizing hospital discharge data (HD) to compare fatal and non-fatal work-related injuries among Hispanic workers in New Jersey

BACKGROUND

This study explores the utilization of Hospital Discharge (HD) data to obtain estimates of work-related non-fatal injuries rates in NJ to determine if Hispanics workers have an increased risk of specific work-related injuries. In addition, HD data are used to compare the rate ratios between fatal and non-fatal injuries in this population to demonstrate the effectiveness of using HD as a surveillance tool for monitoring injury trends and performing evaluations.

METHODS

Several types of fatal and non-fatal injuries were modeled using Poisson regression with the following predictor variables: gender, ethnicity, and year. The estimated number of workers by ethnicity employed in NJ each year was obtained from the U.S. Census Bureau, DataFerrett, Current Population Survey, November 2006, a data mining tool which accesses CPS data.

RESULTS

These analyses, utilizing estimates of working population at-risk, indicate that Hispanic workers have an increased risk of four particular work-related injuries compared with non-Hispanics, and Hispanics were injured at a younger age than non-Hispanics. In addition the rankings of the rate ratios from the comparison between non-fatal and fatal risk estimates were similar; indicating that occupational surveillance of non-fatal injuries is a viable component to be considered.

CONCLUSIONS

HD data are effective for monitoring trends over time across ethnic groups and injury types. Therefore, non-fatal injury surveillance should be considered for targeting specific worker populations for interventions to reduce exposure to workplace hazards, and can be a valuable surveillance tool in efforts to reduce occupational injuries.

Testing for bias in weighted estimating equations

It is very common in regression analysis to encounter incompletely observed covariate information. A recent approach to analyse such data is weighted estimating equations (Robins, J. M., Rotnitzky, A. and Zhao, L. P. (1994), JASA, 89, 846-866, and Zhao, L. P., Lipsitz, S. R. and Lew, D. (1996), Biometrics, 52, 1165-1182). With weighted estimating equations, the contribution to the estimating equation from a complete observation is weighted by the inverse of the probability of being observed. We propose a test statistic to assess if the weighted estimating equations produce biased estimates. Our test statistic is similar to the test statistic proposed by DuMouchel and Duncan (1983) for weighted least squares estimates for sample survey data. The method is illustrated using data from a randomized clinical trial on chemotherapy for multiple myeloma.

Meta-analysis of binary data: which within study variance estimate to use?

We applied a mixed effects model to investigate between- and within-study variation in improvement rates of 180 schizophrenia outcome studies. The between-study variation was explained by the fixed study characteristics and an additional random study effect. Both rate difference and logit models were used. For a binary proportion outcome p(i) with sample size n(i) in the ith study, (circumflexp(i)(1-circumflexp(i))n)(-1) is the usual estimate of the within-study variance sigma(i)(2) in the logit model, where circumflexpi) is the sample mean of the binary outcome for subjects in study i. This estimate can be highly correlated with logit(circumflexp(i)). We used (macronp(i)(1-macronp)n(i))(-1) as an alternative estimate of sigma(i)(2), where macronp is the weighted mean of circumflexp(i)'s. We estimated regression coefficients (beta) of the fixed effects and the variance (tau(2)) of the random study effect using a quasi-likelihood estimating equations approach. Using the schizophrenia meta-analysis data, we demonstrated how the choice of the estimate of sigma(2)(i) affects the resulting estimates of beta and tau(2). We also conducted a simulation study to evaluate the performance of the two estimates of sigma(2)(i) in different conditions, where the conditions vary by number of studies and study size. Using the schizophrenia meta-analysis data, the estimates of beta and tau(2) were quite different when different estimates of sigma(2)(i) were used in the logit model. The simulation study showed that the estimates of beta and tau(2) were less biased, and the 95 per cent CI coverage was closer to 95 per cent when the estimate of sigma(2)(i) was (macronp(1-macronp)n(i))(-1) rather than (circumflexp(i)(1-circumflexp)n(i))(-1). Finally, we showed that a simple regression analysis is not appropriate unless tau(2) is much larger than sigma(2)(i), or a robust variance is used.

Depletion of protein kinase Cepsilon in normal and scleroderma lung fibroblasts has opposite effects on tenascin expression

OBJECTIVE

To determine whether the extracellular matrix protein tenascin-C (TN-C) is overexpressed in lung fibroblasts from systemic sclerosis (SSc) patients, the molecular mechanisms regulating TN-C secretion in SSc and normal lung fibroblasts, and how these processes might contribute to lung fibrosis in SSc patients.

METHODS

TN-C secretion by SSc and normal fibroblasts was compared in vivo (in bronchoalveolar lavage [BAL] fluid) and in vitro (in culture medium). The ability of thrombin to induce TN-C was confirmed at both the protein and the messenger RNA (mRNA) level. The role of protein kinase Cepsilon (PKCepsilon) in the expression of TN-C was evaluated by determining the effects of thrombin on PKCepsilon levels and by directly manipulating PKCepsilon levels via the use of antisense oligonucleotides.

RESULTS

BAL fluid from SSc patients contained high levels of TN-C, whereas that from normal subjects contained little or no TN-C. In vitro, SSc lung fibroblasts expressed much higher amounts of TN-C than did normal lung fibroblasts. Consistent with the idea that thrombin is a physiologic inducer of TN-C, thrombin stimulated TN-C mRNA and protein expression in both SSc and normal lung fibroblasts by a mechanism that required proteolytic cleavage of the thrombin receptor. Surprisingly, thrombin treatment and antisense oligonucleotide-mediated depletion of PKCepsilon indicated that TN-C expression is regulated via opposite signaling mechanisms in SSc and normal cells. In SSc lung fibroblasts, thrombin decreased PKCepsilon levels, and the decreased PKCepsilon induced TN-C secretion; in normal fibroblasts, thrombin increased PKCepsilon levels, and the increased PKCepsilon induced TN-C secretion. Normal and SSc lung fibroblasts also differed in the subcellular localization of PKCepsilon, both before and after thrombin treatment.

CONCLUSION

These studies are the first to demonstrate that thrombin is a potent simulator of TN-C in lung fibroblasts and that PKCepsilon is a critical regulator of TN-C protein levels in these cells. Furthermore, our results indicate that both the regulation of PKCepsilon levels by thrombin and the regulation of TN-C levels by PKCepsilon are defective in SSc lung fibroblasts.

The impact of birth weight on the racial disparity of end-stage renal disease

PURPOSE: Blacks have a high rate of end-stage renal disease (ESRD) and low birthweight (LBW) than whites. LBW has been associated with ESRD. The purpose of this study was to assess impact of LBW on the racial difference in ESRD.METHODS: Patients born in SC after 1950 and diagnosed with ESRD between 1991-1996 were identified from the ESRD registry. Birth weight was compared for 858 black and 372 white patients and 2460 controls matched for age, sex, and race. LBW was defined as birthweight <2500 g.RESULTS: Among patients with ESRD, mean birthweight was lower in blacks than whites (3179 vs 3367 g, p < 0.001). LBW was more common in blacks than whites with ESRD (13.9 vs 7.5%, p = 0.02). The risk ratio for LBW among ESRD patients was 1.4 (95% C.I. 1.1 to 1.8) for blacks and 1.5 (95% C.I. 0.9 to 2.5) for whites. The population attributable risk (PAR) for ESRD due to LBW was greater for blacks than whites (33.6 vs 4.2 per 100,000).CONCLUSIONS: Birthweights were lower and LBW was more common among blacks than whites with ESRD. Moreover, LBW contributed more to the PAR of ESRD in blacks than whites. Thus, LBW may contribute to the greater risk for ESRD in African Americans than Caucasians. This preliminary study indicates that further research on the link between LBW and ESRD could be instructive in understanding the racial health disparities.

A phase II trial of homoharringtonine and caracemide in the treatment of patients with advanced large bowel cancer

Twenty-four previously untreated, ambulatory patients with advanced colorectal carcinoma were treated with either caracemide (11 patients) or homoharringtonine (13 patients). No objective responses were observed in any of the treatment cohorts. Caracemide was well tolerated with the exception of one death due to sepsis. On the homoharringtonine arm one patient died of pulmonary sepsis, one patient experienced grade 4 leukopenia requiring more than 4 weeks of recovery, and an additional patient developed grade 4 renal failure. These severe and unexpected complications caused early termination of accrual to the homoharringtonine arm of the study. These agents have no activity in the treatment of advanced colorectal carcinoma.

Analysis of dichotomous outcome data for community intervention studies

Community intervention trials are becoming increasingly popular as a tool for evaluating the effectiveness of health education and intervention strategies. Typically, units such as households, schools, towns, counties, are randomized to receive either intervention or control, then outcomes are measured on individuals within each of the units of randomization. It is well recognized that the design and analysis of such studies must account for the clustering of subjects within the units of randomization. Furthermore, there are usually both subject level and cluster level covariates that must be considered in the modelling process. While suitable methods are available for continuous outcomes, data analysis is more complicated when dichotomous outcomes are measured on each subject. This paper will compare and contrast several of the available methods that can be applied in such settings, including random effects models, generalized estimating equations and methods based on the calculation of 'design effects', as implemented in the computer package SUDAAN. For completeness, the paper will also compare these methods of analysis with more simplistic approaches based on the summary statistics. All the methods will be applied to a case study based on an adolescent anti-smoking intervention in Australia. The paper concludes with some general discussion and recommendations for routine design and analysis.

Treatment of squamous cell esophageal cancer with topotecan: an Eastern Cooperative Oncology Group Study (E2293)

Seventeen patients with enhanced measurable squamous cell carcinoma of the esophagus were treated with topotecan 1.5 mg/m2 daily for 5 days repeated every 21 days. Toxicity was severe, with 1 death from myelotoxicity and 10 patients with life-threatening myelotoxicity. Severe gastrointestinal toxicity consisting of vomiting was also seen in three patients. No response was seen in any of the patients in the study. Topotecan given in this manner has no activity in squamous cell carcinoma of the esophagus.

Phase II trial of trimetrexate for patients with advanced gastric carcinoma: an Eastern Cooperative Oncology Group study (E1287)

BACKGROUND

A Phase II study was conducted to evaluate the response, duration of response, and duration of survival of patients with measurable gastric carcinoma treated with trimetrexate (TMTX) who had not had prior chemotherapy.

METHODS

Thirty-three patients with unresectable or metastatic gastric adenocarcinoma who had not received previous chemotherapy were treated with intravenous TMTX 12 mg/m(2) daily for 5 days. The dosage of TMTX was reduced to 8 mg/m(2) daily for 5 days for those who had received prior radiotherapy. The cycle was repeated every 3 weeks until disease progression or unacceptable toxicity occurred.

RESULTS

Thirty-three patients could be analyzed with follow-up data. There was one Grade 5 (lethal) toxicity and four Grade 4 toxicities. Hematologic toxicity was the most common. The overall response rate was 21%, the overall median progression free survival was 2.7 months, and the overall median survival was 5.9 months for the entire cohort. No patients were alive at last follow-up.

CONCLUSIONS

Though TMTX as a single agent has activity in gastric carcinoma with manageable toxicity, it cannot be recommended for routine use as a single agent due to the brief duration of response and median survival.

A phase II study of 5-fluorouracil, leucovorin, and interferon-alpha in the treatment of patients with metastatic or recurrent gastric carcinoma: an Eastern Cooperative Oncology Group study (E5292)

BACKGROUND

Chemotherapy has a limited impact on adenocarcinoma of the stomach. Although biochemical modulation of 5-fluorouracil (5-FU) by leucovorin (LV) and interferon-alpha (IFN-alpha) has improved the outcomes of patients with metastatic colorectal carcinoma compared with 5-FU alone, this approach has not been extensively evaluated in the treatment of advanced gastric carcinoma.

METHODS

Twenty-seven patients with bidimensionally measurable, metastatic gastric carcinoma and an Eastern Cooperative Oncology Group performance status of 0 or 1 received the combination of IFN-alpha (5 million U/m2 administered subcutaneously daily on Days 1-7), LV (500 mg/m2 administered intravenously over 30 minutes immediately after IFN-alpha on Days 2-6), and 5-FU (370 mg/m2 given as an intravenous bolus 60 minutes after LV on Days 2-6), with treatment repeated every 4 weeks. Oral cryotherapy was administered routinely before each dose of 5-FU to reduce the incidence of severe stomatitis.

RESULTS

The median age of the patients was 58 years (range, 20-76), and 22 patients had residual, unresectable primary lesions. The median number of cycles received was 3 (range, 1-11). Of 24 patients who received at least 2 cycles of treatment, 15 (62.5%) did not require dose reduction for toxicity during the initial 2 cycles. The predominant toxicities were gastrointestinal: diarrhea and stomatitis of Grade 3-4 occurred in 28.6% and 35.7% of patients, respectively. Other severe (Grade 3-4) toxicities were granulocytopenia (which occurred in 21.4% of patients) and fatigue (in 10.7%). Fever and flu-like symptoms were common but usually mild. Of 24 patients who were evaluable for response, 3 had partial responses (PR) of 16, 23, and 33 weeks' duration, respectively, for a response rate of 12.5% (95% confidence interval = 2.7-32.4%). Two additional patients had reductions in tumor size sufficient for PR, but scans to document the minimum required response duration of 4 weeks were not obtained before progressive disease occurred. The median progression-free and overall survivals were 2.5 and 7.8 months, respectively.

CONCLUSIONS

Although this regimen can be administered safely with appropriate supportive care to patients with good performance status, it has limited therapeutic activity in patients with advanced gastric carcinoma.

Using a hypothetical case to measure differences in treatment aggressiveness among physicians in Canada, Germany and the United States

Variations in physician practice style, within and between countries, account for much of the differences in the utilization of scarce health care resources. Practice style differences are particularly important at the end of life, when a substantial amount of resources are consumed. We use a hypothetical case of a severely ill elderly patient to identify factors associated with aggressive treatment and to test whether physicians in the US practice differently from their counterparts in other countries. Data come from a random sample of practicing physicians in three industrialized countries, the United States, Canada and Germany (N = 1369). Although the case stated that the chance of survival of the patient was low, 73% of all physicians selected the aggressive treatment. Physicians from the United States were the most aggressive (86%), followed by Germany (68%) and Canada (61%). Practicing in the United States was the strongest predictor of aggressiveness in the multiple linear logistic regression; German and Canadian physicians were one fourth as likely to use aggressive treatment. Specialty training, older age and being a resident all increased the likelihood of selecting the more aggressive treatment. The fear of being sued for malpractice and income did not have an effect on treatment decisions.

Phase II trial of preoperative radiation therapy and chemotherapy for patients with localized, resectable adenocarcinoma of the pancreas: an Eastern Cooperative Oncology Group Study

PURPOSE

A prospective, multiinstitutional trial was initiated in 1991 to examine the tolerance to and efficacy of a program of preoperative chemoradiotherapy (CTRT) and surgical resection for patients with localized adenocarcinoma of the pancreas.

PATIENTS AND METHODS

Fifty-three patients were assessable for analysis, with a median follow-up of 52 months for survivors. Radiation therapy (RT) totaling 5,040 cGy in 180 cGy fractions with mitomycin 10 mg/m2 day 2 and fluorouracil (5-FU) 1,000 mg/m2/d continuous infusion days 2 through 5 and 29 through 32 were given as preoperative adjuvant therapy. Twelve patients did not proceed to surgery (one death, one toxicity, three local progression, six distant metastases, one intercurrent illness), whereas 41 patients underwent surgery. Of these, 17 patients did not have resection (11, hepatic and/or peritoneal metastases and six local extension that precluded resection). Twenty-four patients had tumor resection (19 Whipple, four total pancreatectomy, one distal pancreatectomy).

RESULTS

Treatment toxicity was primarily hematologic, although a comparable number suffered biliary tract complications, either from obstruction or cholangitis as a result of an occluded stent or the primary tumor. There was one postoperative death. Median survival for the entire group and for the 24 patients with resection was 9.7 and 15.7 months. This survival rate reflected the advanced state of most resected cancers (positive peritoneal cytology, three patients; margins within 2 mm, 13 patients; involved lymph nodes, four patients; and need for superior mesenteric vein (SMV) resection, four patients). Tumor progression was most frequent at metastatic sites.

CONCLUSION

This preoperative CTRT protocol was feasible and safe in a cooperative group setting. Entry of patients with advanced tumors probably accounted for the suboptimal resectability and survival results.

Phase II trial of prolonged continuous infusion of 5-fluorouracil and interferon-alpha in patients with advanced pancreatic cancer. Eastern Cooperative Oncology Group Protocol 3292

Evidence suggests that interferon-alpha (IFN-alpha) augments the antineoplastic activity of 5-fluorouracil (5-FU) in human adenocarcinoma cell lines in vitro and may enhance the efficacy of 5-FU in patients with advanced colorectal carcinoma. In addition, 5-FU may be more effective when given as a prolonged, continuous i.v. infusion (PCI). The Eastern Cooperative Oncology Group performed a Phase II trial of PCI 5-FU plus IFN-alpha in patients with advanced pancreatic carcinoma. Twenty-six patients with advanced, surgically incurable adenocarcinoma of the pancreas received PCI 5-FU (250 mg/m2 daily for 28 days) in combination with IFN-alpha (5 x 10(6) IU/m2 s.c. thrice weekly). Treatment cycles were repeated 14 days or longer after completion of the previous cycle. Treatment was interrupted prior to day 28 if intolerable toxicity developed, and the dose of 5-FU was reduced in subsequent cycles. Partial response occurred in two of 24 evaluable patients (8%; 95% confidence interval, 0-19%). The majority of the study group (88%) had liver metastases. Patients whose serum lactate dehydrogenase (LDH) was more than twofold elevated developed 5-FU-related toxicity significantly sooner than patients with smaller elevations in serum LDH (9 vs. 22 days; p = 0.003). A similar trend was observed for patients with a more than twofold elevation in serum glutamic-oxaloacetic transaminase (SGOT; 9 vs. 15 days; p = 0.07). In conclusion, PCI 5-FU plus IFN-alpha has minimal activity in patients with advanced pancreatic carcinoma, and elevated serum LDH and/or SGOT may be useful for predicting greater toxicity from 5-FU-based therapy in patients with liver metastases.

Regression analysis with missing covariate data using estimating equations

In regression analysis, missing covariate data has been among the most common problems. Frequently, practitioners adopt the so-called complete-case analysis, i.e., performing the analysis on only a complete dataset after excluding records with missing covariates. Performing a complete-case analysis is convenient with existing statistical packages, but it may be inefficient since the observed outcomes and covariates on those records with missing covariates are not used. It can even give misleading statistical inference if missing is not completely at random. This paper introduces a joint estimating equation (JEE) for regression analysis in the presence of missing observations on one covariate, which may be thought of as a method in a general framework for the missing covariate data problem proposed by Robins, Rotnitzky, and Zhao (1994, Journal of the American Statistical Association 89, 846-866). A generalization of JEE to more than one such covariate is discussed. The JEE is generally applicable to estimating regression coefficients from a regression model, including linear and logistic regression. Provided that the missing covariate data is either missing completely at random or missing at random (in addition to mild regularity conditions), estimates of regression coefficients from the JEE are consistent and have an asymptotic normal distribution. Simulation results show that the asymptotic distribution of estimated coefficients performs well in finite samples. Also shown through the simulation study is that the validity of JEE estimates depends on the correct specification of the probability function that characterizes the missing mechanism, suggesting a need for further research on how to robustify the estimation from making this nuisance assumption. Finally, the JEE is illustrated with an application from a case-control study of diet and thyroid cancer.

Long-term pulmonary toxicity of multiagent chemotherapy including bleomycin and cyclophosphamide in osteosarcoma survivors

PURPOSE

To assess long-term pulmonary effects of multiagent chemotherapy, we studied serial pulmonary function tests (PFTs) of 35 children with osteosarcoma up to 12 years after diagnosis.

PATIENTS AND METHODS

We analyzed 84 sets of PFTs from 35 patients diagnosed with osteosarcoma between 1981 and 1991. They received bleomycin, cyclophosphamide, methotrexate, doxorubicin, cisplatin, and actinomycin D over 9-12 months and we performed PFTs from 3 days to 152 months after diagnosis. Time period I included 36 PFTs (43%) performed between 1 and 5 months from diagnosis, time period II included 20 PFTs (24%) performed between 8 and 12 months from diagnosis, and time period III included 28 PFTs (33%) performed between 12 and 119 months from diagnosis. Total lung capacity (TLC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and carbon monoxide diffusing capacity (DLCO) were analyzed. Maximal respiratory pressures and arterial blood gases were measured to assess muscle weakness and gas exchange, respectively. Mean differences in PFTs were compared among the three time periods and between time period pairs.

RESULTS

All mean PFT values showed significant differences among time periods. Significant decline in DLCO; (P=.012), TLC (P=.020), and FEV1 (P=.028) between time periods I and II were noted followed by a trend towards recovery between time periods II and III. Time periods I and III were not significantly different from one another. Mean PFTs performed after 2 years of diagnosis were not different from mean PFTs performed from diagnosis at 2 years.

CONCLUSION

This dosage regimen of multi-agent chemotherapy for osteosarcoma patients caused a transient, but significant, decline in PFTs within 8-12 months after administration but appears to cause no significant long-term pulmonary function abnormalities.

Phase II trial of taxol in patients with adenocarcinoma of the upper gastrointestinal tract (UGIT). The Eastern Cooperative Oncology group (ECOG) results

Taxol was administered as a 24-hour continuous infusion at 250 mg/m2 in this Phase II trial in patients with adenocarcinomas of the upper gastrointestinal tract (UGIT). Twenty-five patients were entered between July 1991 and June 1992, twenty-three were eligible and were evaluated for toxicity and twenty-two were assessable for response. There was one partial response (4.5%) in a patient with liver metastases, with a duration of 6 months. Toxicity was primarily neutropenia. Taxol as a single agent appears to have little activity in adenocarcinoma of the UGIT.

Hepatocellular carcinoma. An ECOG randomized phase II study of beta-interferon and menogaril

This study was undertaken to investigate the response rate, time to treatment failure and survival time of patients with hepatocellular cancer (HCC) treated with beta-interferon or menogaril. Sixty-nine patients with histologically confirmed, advanced, measurable hepatocellular carcinoma were randomized to receive beta-interferon or menogaril. Eligibility criteria included an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, 2, or 3, as well as adequate kidney and liver function and hematologic reserve. The number of patients with lethal, life-threatening, and severe toxicities on beta-interferon were 1, 3, and 12 and on menogaril 2, 5, and 10, respectively. No objective responses were documented among the 61 patients who had HCC, histologically reviewed and confirmed. The time to treatment failure was 6.7 weeks on beta-interferon and 8.6 weeks on menogaril. The median survival time was 11.1 weeks on beta-interferon and 23.1 weeks on menogaril (South African patients 10.1 weeks). The difference is not significant. Poor prognostic factors were jaundice, age, and associated hepatitis. After controlling for other covariates, beta-interferon appears to increase the relative risk of dying by 2.7. This trial reconfirms the importance, previously reported by ECOG of jaundice and age in the prognosis of patients with HCC. It shows that further trials with neither beta-interferon nor menogaril are warranted.

Dietary vitamin A intake and the risk of mortality among children

Increased consumption of dietary vitamin A is advocated as a long-term solution to vitamin A deficiency. We prospectively examined the relationship of dietary vitamin A intake and child mortality among 28,753 Sudanese children aged 6 mo to 6 y, who participated in a trial of vitamin A supplementation. After 18 mo of follow-up, 232 children died. Total dietary vitamin A intake was strongly and inversely associated with risk of mortality. The age- and sex-adjusted relative risk (RR) of mortality for a comparison of children in extreme quintiles was 0.35 (95% CIs 0.21-0.60; P for trend over quintiles < 0.0001). Even after possible confounding by socioeconomic variables was adjusted for, vitamin A intake was significantly protective (multi-variate relative risk 0.53). Dietary vitamin A intake was especially protective among children who were wasted and stunted or who had diarrhea or cough. These prospective data support an important role of dietary vitamin A in reducing childhood mortality in developing countries.

Vitamin A supplementation and dietary vitamin A in relation to the risk of xerophthalmia

We examined the effect of 60-mg (200,000-IU) supplements of vitamin A administered every 6 mo on the incidence of xerophthalmia among preschool children who were free of eye symptoms and signs of vitamin A deficiency. We also prospectively studied the relationship of dietary vitamin A intake with the same endpoint. After 18 mo of follow-up, 400 children developed xerophthalmia during 80,104 child-periods of follow-up. Vitamin A supplementation only modestly reduced the risk of xerophthalmia (relative risk 0.88, 95% confidence interval 0.72-1.07, P = 0.19). On the other hand, total dietary vitamin A intake was strongly associated with reduced risk of xerophthalmia; the multivariate relative risk when children in extreme quintiles were compared was 0.38 (95% confidence interval 0.19-0.74; P for trend over quintiles = 0.002). These results emphasize the need for further data on factors that modify the bioavailability of large-dose vitamin A supplements. Increased consumption of inexpensive vegetables and fruits is highly likely to reduce significantly the risks of vitamin A deficiency, including nutritional blindness in developing countries.

Designs and analysis of two-stage studies

This paper concerns the design and analysis of two-stage studies, where, at the first stage, the response and the exposure variables are available among a large group of subjects. The other covariables, however, are available in only a subset of the large group, obtained in a second-stage sample. This paper introduces a class of twelve such two-stage designs, including two-stage case-control and case-cohort designs as special cases. In analysing such two-stage data, one objective is to extract information about the relationship between the exposure variable and the response after controlling for other covariables. We discuss three statistical methods to analyse the data and report results of Monte Carlo stimulation to study the efficiency of the three methods.

Streptozocin-doxorubicin, streptozocin-fluorouracil or chlorozotocin in the treatment of advanced islet-cell carcinoma

BACKGROUND

The combination of streptozocin and fluorouracil has become the standard therapy for advanced islet-cell carcinoma. However, doxorubicin has also been shown to be active against this type of tumor, as has chlorozotocin, a drug that is structurally similar to streptozocin but less frequently causes vomiting.

METHODS

In this multicenter trial, we randomly assigned 105 patients with advanced islet-cell carcinoma to receive one of three treatment regimens: streptozocin plus fluorouracil, streptozocin plus doxorubicin, or chlorozotocin alone. The 31 patients in whom the disease did not respond to treatment were crossed over to chlorozotocin alone or to one of the combination regimens.

RESULTS

Streptozocin plus doxorubicin was superior to streptozocin plus fluorouracil in terms of the rate of tumor regression, measured objectively (69 percent vs. 45 percent, P = 0.05), and the length of time to tumor progression (median, 20 vs. 6.9 months; P = 0.001). Streptozocin plus doxorubicin also had a significant advantage in terms of survival (median, 2.2 vs. 1.4 years; P = 0.004) that was accentuated when we considered long-term survival (greater than 2 years). Chlorozotocin alone produced a 30 percent regression rate, with the length of time to tumor progression and the survival time equivalent to those observed with streptozocin plus fluorouracil. Crossover therapy after the failure of either chlorozotocin alone or one of the combination regimens produced an overall response rate of only 17 percent, and the responses were transient. Toxic reactions to all regimens included vomiting, which was least severe with chlorozotocin; hematologic depression; and, with long-term therapy, renal insufficiency.

CONCLUSIONS

The combination of streptozocin and doxorubicin is superior to the current standard regimen of streptozocin plus fluorouracil in the treatment of advanced islet-cell carcinoma. Chlorozotocin alone is similar in efficacy to streptozocin plus fluorouracil, but it produces fewer gastrointestinal side effects than the regimens containing streptozocin. It therefore merits study as a constituent of combination drug regimens.

Issues in the analysis of repeated categorical outcomes

This paper discusses statistical methods for the analysis of repeated observations of categorical variables as they might arise in longitudinal studies. Two general types of models are described: marginal models that give representations for the marginal distribution of response at each occasion, and transitional models that give representations for the transition probabilities between outcome states at successive occasions. The conceptual and technical differences are discussed and recent work advancing both approaches is reviewed. The two approaches are illustrated through analysis of repeated observations on interval history of the respiratory symptom 'persistent wheeze' in preadolescent children.