The financial impact of teaching surgical residents in the operating room

BACKGROUND

There have been no published data regarding the cost of training surgical residents in the operating room.

METHODS

At the University of Tennessee Medical Center-Knoxville, in addition to resident-performed teaching cases, some cases are performed without the assistance of residents by the same faculty.

RESULTS

Sixty-two case categories involving 14,452 cases were compared for operative times alone. In 46 case categories (10,787 procedures), resident operative times were longer than faculty alone. In 16 case categories, resident operating times were shorter than faculty times. The net incremental operative time cost was 2,050 hours between July 1993 and March 1997. Assuming 4 years of operative training for 11 graduating chief residents, the cost per graduating resident was $47,970.

CONCLUSION

Extrapolated to a national annual cost for the 1,014 general surgery residents who completed training in the 1997 academic year, the annual cost of training residents in the operating room is $53 million. This high monetary cost suggests the need for digital skills, selection criteria, the development of training curriculum and resource facilities, the pre-operating room need for suturing and stapling techniques, and perhaps the acquisition of virtual surgery training modules.

Severe functional declines, work disability, and increased mortality in seventy-five rheumatoid arthritis patients studied over nine years

Seventy-five patients with rheumatoid arthritis (RA) were reviewed 9 years after an extensive evaluation which included quantitative measures of functional capacity. These patients had received multiple intraarticular injections of thiotepa with corticosteroids early in their course, but appear demographically and functionally similar to other RA patients who had not received this therapy. Severe morbidity was seen over the 9-year period in the 55 surviving patients, including significantly lower overall functional capacity in 92% of patients studied, lower grip strength in 93%, and longer button test results in 84%. Work disability occurred in 85% of patients under age 65 who had been working full-time at disease onset. There was increased mortality at the 9-year review, similar to most reported series of RA patients from referral centers; however, a significant increase in neoplasia, which was of concern because of the use of intraarticular thiotepa, was not seen. In terms of functional capacity, including responses to questions about ability to perform activities, walking time, and the button test, those patients who had died prior to review had significantly lower baseline values than did those who survived. Of the 75 patients, 20 had died and 51 had lost significant functional capacity over a 9-year period, documented by quantitative measures of functional capacity.

A prospective, randomized, study comparing early percutaneous dilational tracheotomy to prolonged translaryngeal intubation (delayed tracheotomy) in critically ill medical patients

OBJECTIVE

The timing of tracheotomy in patients requiring mechanical ventilation is unknown. The effects of early percutaneous dilational tracheotomy compared with delayed tracheotomy in critically ill medical patients needing prolonged mechanical ventilation were assessed.

DESIGN

Prospective, randomized study.

SETTING

Medical intensive care units.

PATIENTS

One hundred and twenty patients projected to need ventilation >14 days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were prospectively randomized to either early percutaneous tracheotomy within 48 hrs or delayed tracheotomy at days 14-16. Time in the intensive care unit and on mechanical ventilation and the cumulative frequency of pneumonia, mortality, and accidental extubation were documented. The airway was assessed for oral, labial, laryngeal, and tracheal damage. Early group showed significantly less mortality (31.7% vs. 61.7%), pneumonia (5% vs. 25%), and accidental extubations compared with the prolonged translaryngeal group (0 vs. 6). The early tracheotomy group spent less time in the intensive care unit (4.8 +/- 1.4 vs. 16.2 +/- 3.8 days) and on mechanical ventilation (7.6 +/- 2.0 vs. 17.4 +/- 5.3 days). There was also significantly more damage to mouth and larynx in the prolonged translaryngeal intubation group.

CONCLUSIONS

This study demonstrates that the benefits of early tracheotomy outweigh the risks of prolonged translaryngeal intubation. It gives credence to the practice of subjecting this group of critically ill medical patients to early tracheotomy rather than delayed tracheotomy.

Predictors of failure of noninvasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a multi-center study

CONTEXT

In patients with hypoxemic acute respiratory failure (ARF), randomized studies have shown noninvasive positive pressure ventilation (NPPV) to be associated with lower rates of endotracheal intubation. In these patients, predictors of NPPV failure are not well characterized.

OBJECTIVE

To investigate variables predictive of NPPV failure in patients with hypoxemic ARF.

DESIGN

Prospective, multicenter cohort study.

SETTING

Eight Intensive Care Units (ICU) in Europe and USA.

PATIENTS

Of 5,847 patients admitted between October 1996 and December 1998, 2,770 met criteria for hypoxemic ARF. Of these, 2,416 were already intubated and 354 were eligible for the study.

RESULTS

NPPV failed in 30% (108/354) of patients. The highest intubation rate was observed in patients with ARDS (51%) or community-acquired pneumonia (50%). The lowest intubation rate was observed in patients with cardiogenic pulmonary edema (10%) and pulmonary contusion (18%). Multivariate analysis identified age > 40 years (OR 1.72, 95% CI 0.92-3.23), a simplified acute physiologic score (SAPS II) > or = 35 (OR 1.81, 95% CI 1.07-3.06), the presence of ARDS or community-acquired pneumonia (OR 3.75, 95% CI 2.25-6.24), and a PaO2:FiO2 < or = 146 after 1 h of NPPV (OR 2.51, 95% CI 1.45-4.35) as factors independently associated with failure of NPPV. Patients requiring intubation had a longer duration of ICU stay ( P < 0.001), higher rates of ventilator-associated pneumonia and septic complications ( P < 0.001), and a higher ICU mortality ( P < 0.001).

CONCLUSIONS

In hypoxemic ARF, NPPV can be successful in selected populations. When patients have a higher severity score, an older age, ARDS or pneumonia, or fail to improve after 1 h of treatment, the risk of failure is higher.

Impacts of Fine Root Turnover on Forest NPP and Soil C Sequestration Potential

Estimates of forest net primary production (NPP) demand accurate estimates of root production and turnover. We assessed root turnover with the use of an isotope tracer in two forest free-air carbon dioxide enrichment experiments. Growth at elevated carbon dioxide did not accelerate root turnover in either the pine or the hardwood forest. Turnover of fine root carbon varied from 1.2 to 9 years, depending on root diameter and dominant tree species. These long turnover times suggest that root production and turnover in forests have been overestimated and that sequestration of anthropogenic atmospheric carbon in forest soils may be lower than currently estimated.

The association of diabetes and glucose control with surgical-site infections among cardiothoracic surgery patients

OBJECTIVE

To assess the importance of diabetes, diabetes control, hyperglycemia, and previously undiagnosed diabetes in the development of surgical-site infections (SSIs) among cardiothoracic surgery patients.

SETTING

A 540-bed tertiary-care university-affiliated hospital.

DESIGN

Prospective cohort and case-control studies.

PATIENTS

All patients having cardiothoracic surgery between November 1998 and September 1999 were eligible for participation. One thousand patients had preoperative hemoglobin A1c determinations. Seventy-four patients with SSIs were identified.

RESULTS

Diabetes (odd ratio [OR], 2.76; P<.001) and postoperative hyperglycemia (OR, 2.02; P=.007) were independently associated with development of SSIs. Among known diabetics, elevated hemoglobin A1c values were not associated with a statistically significantly increased risk of infection; the mean A1c value was 8.44% among those with infections compared with 7.80% for those without (P=.09). Forty-two (6%) of 700 patients without prior diabetes history had evidence of undiagnosed diabetes; their infection rate was comparable to that of known diabetics (3/42 [7%] vs 17/300 [6%]; P=.72). An additional 30% of nondiabetics had elevated hemoglobin A1c determinations or perioperative hyperglycemia.

CONCLUSIONS

Postoperative hyperglycemia and previously undiagnosed diabetes are associated with development of SSIs among cardiothoracic surgery patients. Screening for diabetes and hyperglycemia among patients having cardiothoracic surgery may be warranted to prevent postoperative and chronic complications of this metabolic abnormality.

CO2 enhancement of forest productivity constrained by limited nitrogen availability

Stimulation of terrestrial plant production by rising CO(2) concentration is projected to reduce the airborne fraction of anthropogenic CO(2) emissions. Coupled climate-carbon cycle models are sensitive to this negative feedback on atmospheric CO(2), but model projections are uncertain because of the expectation that feedbacks through the nitrogen (N) cycle will reduce this so-called CO(2) fertilization effect. We assessed whether N limitation caused a reduced stimulation of net primary productivity (NPP) by elevated atmospheric CO(2) concentration over 11 y in a free-air CO(2) enrichment (FACE) experiment in a deciduous Liquidambar styraciflua (sweetgum) forest stand in Tennessee. During the first 6 y of the experiment, NPP was significantly enhanced in forest plots exposed to 550 ppm CO(2) compared with NPP in plots in current ambient CO(2), and this was a consistent and sustained response. However, the enhancement of NPP under elevated CO(2) declined from 24% in 2001-2003 to 9% in 2008. Global analyses that assume a sustained CO(2) fertilization effect are no longer supported by this FACE experiment. N budget analysis supports the premise that N availability was limiting to tree growth and declining over time--an expected consequence of stand development, which was exacerbated by elevated CO(2). Leaf- and stand-level observations provide mechanistic evidence that declining N availability constrained the tree response to elevated CO(2); these observations are consistent with stand-level model projections. This FACE experiment provides strong rationale and process understanding for incorporating N limitation and N feedback effects in ecosystem and global models used in climate change assessments.

Quantitative characterization of trace levels of PFOS and PFOA in the Tennessee River

Although there is evidence of widespread distribution of organic fluorochemicals such as perfluorooctane sulfonate and perfluorooctanoate, in the environment, the versatility of these compounds in industrial and commercial applications complicates characterization of pathways into the environment. A solid-phase extraction method coupled with HPLC-negative-ion electrospray tandem mass spectrometry was developed to quantitatively measure trace levels of organic fluorochemicals in drinking water and surface water. Using this method, certain fluorochemicals can be quantitatively measured in water samples down to 25 ppt, a level well below calculated drinking water advisory levels. To assess fluorochemical distribution in a localized geography and to ascertain whether fluorochemical manufacturing facilities contribute to environmental levels of fluorochemicals, 40 water samples were collected on an 80-mi stretch of the Tennessee River, near a fluorochemical manufacturing site in Decatur, AL. Low levels (ppt) of perfluorooctane sulfonate were determined throughout the stretch of river sampled. Concentrations of the measured fluorochemicals increased downstream of the fluorochemical manufacturing facility, indicating that effluent from manufacturing is one likely source of organic fluorochemicals into the river.

Gun ownership as a risk factor for homicide in the home

BACKGROUND

It is unknown whether keeping a firearm in the home confers protection against crime or, instead, increases the risk of violent crime in the home. To study risk factors for homicide in the home, we identified homicides occurring in the homes of victims in three metropolitan counties.

METHODS

After each homicide, we obtained data from the police or medical examiner and interviewed a proxy for the victim. The proxies' answers were compared with those of control subjects who were matched to the victims according to neighborhood, sex, race, and age range. Crude and adjusted odds ratios were calculated with matched-pairs methods.

RESULTS

During the study period, 1860 homicides occurred in the three counties, 444 of them (23.9 percent) in the home of the victim. After excluding 24 cases for various reasons, we interviewed proxy respondents for 93 percent of the victims. Controls were identified for 99 percent of these, yielding 388 matched pairs. As compared with the controls, the victims more often lived alone or rented their residence. Also, case households more commonly contained an illicit-drug user, a person with prior arrests, or someone who had been hit or hurt in a fight in the home. After controlling for these characteristics, we found that keeping a gun in the home was strongly and independently associated with an increased risk of homicide (adjusted odds ratio, 2.7; 95 percent confidence interval, 1.6 to 4.4). Virtually all of this risk involved homicide by a family member or intimate acquaintance.

CONCLUSIONS

The use of illicit drugs and a history of physical fights in the home are important risk factors for homicide in the home. Rather than confer protection, guns kept in the home are associated with an increase in the risk of homicide by a family member or intimate acquaintance.

Increasing use of antidepressants in pregnancy

OBJECTIVE

The purpose of this study was to quantify the rate of exposures to antidepressants during pregnancy in a large cohort of women.

STUDY DESIGN

This was a retrospective cohort study of 105,335 pregnancies among women enrolled in Tennessee Medicaid from 1999-2003. Pregnancies were classified according to antidepressant exposures during pregnancy using previously validated computerized pharmacy records linked with birth certificates.

RESULTS

During the study period, 8.7% of women giving birth had exposure to any antidepressant; 6.2% had exposure to a selective serotonin reuptake inhibitor. Maternal age > 25 years (P < .0001), white race (P < .0001), and education > 12 years (P = .008) were significant predictors of antidepressant exposure. The proportion of pregnancies with antidepressant use increased from 5.7% of pregnancies in 1999 to 13.4% of pregnancies in 2003 (p < .0001). The increase was mostly accounted for by increases in selective serotonin reuptake inhibitor exposures.

CONCLUSION

There is an urgent need for further studies that better quantify the fetal consequences of exposure to antidepressants.

Physical activity, exercise, and inflammatory markers in older adults: findings from the Health, Aging and Body Composition Study

OBJECTIVES

To examine the association between physical activity and inflammatory markers, with consideration for body fatness and antioxidant use.

DESIGN

Cross-sectional study, using baseline data from the Health, Aging and Body Composition Study.

SETTING

Metropolitan areas surrounding Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Black and white, well-functioning men and women (N=3,075), aged 70 to 79.

MEASUREMENTS

Interviewer-administered questionnaires of previous-week household, walking, exercise, and occupational/volunteer physical activities. Analysis of covariance was used to examine the association between activity level and serum C-reactive protein (CRP), interleukin-6 (IL-6), and plasma tumor necrosis factor alpha (TNFalpha) with covariate adjustment. Antioxidant supplement use (multivitamin, vitamins E or C, beta carotene) was evaluated as an effect modifier of the association.

RESULTS

Higher levels of exercise were associated with lower levels of CRP (P<.01), IL-6 (P<.001), and TNFalpha (P=.02) (e.g., CRP=1.95 mg/L for no exercise and 1.72 for >180 min/wk). Adjustment for body fatness attenuated the associations somewhat. Use of antioxidant supplements modified the CRP (P(interaction)=.01) and IL-6 (P(interaction)=.08) associations such that concentrations were low in those taking supplements (e.g., CRP=1.79-1.84 across exercise levels) and higher in nonsupplement users who did no exercise (2.03) than in those who did the most (1.72). Among nonexercisers, higher levels of other physical activity were related to lower levels of CRP (P<.01) and IL-6 (P=.02) but not TNFalpha (P=.36), even after accounting for body fat.

CONCLUSION

Inflammatory markers are lower in older adults with higher levels of exercise and nonexercise activity and in antioxidant supplement users regardless of exercise level.

An automated database case definition for serious bleeding related to oral anticoagulant use

PURPOSE

Bleeding complications are a serious adverse effect of medications that prevent abnormal blood clotting. To facilitate epidemiologic investigations of bleeding complications, we developed and validated an automated database case definition for bleeding-related hospitalizations.

METHODS

The case definition utilized information from an in-progress retrospective cohort study of warfarin-related bleeding in Tennessee Medicaid enrollees 30 years of age or older. It identified inpatient stays during the study period of January 1990 to December 2005 with diagnoses and/or procedures that indicated a current episode of bleeding. The definition was validated by medical record review for a sample of 236 hospitalizations.

RESULTS

We reviewed 186 hospitalizations that had medical records with sufficient information for adjudication. Of these, 165 (89%, 95%CI: 83-92%) were clinically confirmed bleeding-related hospitalizations. An additional 19 hospitalizations (10%, 7-15%) were adjudicated as possibly bleeding-related. Of the 165 clinically confirmed bleeding-related hospitalizations, the automated database and clinical definitions had concordant anatomical sites (gastrointestinal, cerebral, genitourinary, other) for 163 (99%, 96-100%). For those hospitalizations with sufficient information to distinguish between upper/lower gastrointestinal bleeding, the concordance was 89% (76-96%) for upper gastrointestinal sites and 91% (77-97%) for lower gastrointestinal sites.

CONCLUSION

A case definition for bleeding-related hospitalizations suitable for automated databases had a positive predictive value of between 89% and 99% and could distinguish specific bleeding sites.

Validation of 1989 Tennessee birth certificates using maternal and newborn hospital records

In 1989, the state of Tennessee adopted a new birth certificate which incorporates changes recommended by the National Center for Health Statistics in the revised US Standard Certificate of Live Birth. The data now being collected are intended to provide improved information for understanding maternal and infant health issues. To assess data quality, the authors compared information reported on the 1989 Tennessee birth certificates with the same data obtained from an ongoing case-control study in which the delivery hospital medical records of mothers and infants were reviewed by trained nurse abstractors using a structured data collection instrument. Cases (n = 1,016) were all infants born in Tennessee in 1989 with birth weights less than 1,500 g or other infants who died during the first 28 days of life. The infants were identified from linked birth-death certificate files. Control infants (n = 634) were randomly selected from the noncase population. The most reliable information obtained from birth certificates was descriptive demographic data and birth weight. The quality of information obtained from the new birth certificate checkboxes varied. Routine medical procedures were better reported on the birth certificates than relatively uncommon conditions and occurrences, even serious ones. Caution is needed in using birth certificate data for assessment of maternal medical risk factors, complications of labor and delivery, abnormal conditions of the newborn, and congenital anomalies, since sensitivity is low.

A randomized, controlled trial of a geriatric assessment unit in a community rehabilitation hospital

We conducted a randomized trial in a community rehabilitation hospital to determine the effect of treatment in a geriatric assessment unit on the physical function, institutionalization rate, and mortality of elderly patients. Functionally impaired elderly patients (mean age, 78.8 years) who were recovering from acute medical or surgical illnesses and were considered at risk for nursing home placement were randomly assigned either to the geriatric assessment unit (n = 78) or to a control group that received usual care (n = 77). The two groups were similar at entry and were stratified according to the perceived risk of an immediate nursing home placement. After six months, the patients treated in the geriatric assessment unit had significantly more functional improvement in three of eight basic self-care activities (P less than 0.05). Those in the lower-risk stratum had significantly more improvement in seven of eight self-care activities. Both six weeks and six months after randomization, significantly more patients treated in the geriatric assessment unit than controls (79 vs. 61 percent after six months) were residing in the community. During the year of follow-up, the control patients had more nursing home stays of six months or longer (10 vs. 3; P less than 0.05). However, there was no difference between the groups in the mean number of days spent in health care facilities (acute care hospital, nursing home, or rehabilitation hospital). Survival analysis showed a trend toward fewer deaths among the patients treated in the geriatric assessment unit, and mortality was significantly reduced in the patients considered to be at lower risk of immediate nursing home placement (P less than 0.05). We conclude that the treatment of selected elderly patients in a specialized geriatric rehabilitation unit improves function, decreases the risk of nursing home placement, and may reduce mortality. The beneficial effects on mortality and function appear greatest for patients at a moderate rather than high risk of nursing home placement.

Behavior problems in children before first recognized seizures

OBJECTIVE

It is not known when behavior problems begin in children with epilepsy. The purposes of this study were to: 1) describe the rates of behavior problems in children before their first recognized seizure, 2) determine the differences in behavior problems between children with a first recognized seizure and their healthy siblings, and 3) identify the seizure variables early in the course of the condition that are associated with behavior problems before the first recognized seizure.

METHODS

The sample was 224 children (4-14 years old) with a first recognized seizure and their 135 healthy siblings. As part of a larger study, computer-assisted structured telephone interviews were conducted with mothers to measure child and sibling behavior problems. Behavior problems were measured using the Child Behavior Checklist. Frequencies, t tests, correlational analysis, and multiple regression were used to analyze data.

RESULTS

Higher than expected rates of behavior problems in the 6 months before the first recognized seizure were found in the total seizure sample, with 32.1% being in the clinical or at-risk range. Rates were highest in children who had previous events that were probably seizures, with 39.5% in the clinical or at-risk range. Children with seizures had significantly higher Total, Internalizing, Attention, Thought, and Somatic Complaints problem scores than their nearest-in-age healthy siblings. Within the seizure sample, variables significantly associated with behavior problems after adjusting for research site, child sex, child age, and socioeconomic status (as represented by primary caregiver's education) were interactions of previously unrecognized seizures with gender and epilepsy syndrome/type of seizures.

CONCLUSIONS

Children with previously unrecognized seizures are already at increased risk for behavior problems at the time of their first recognized seizure. These findings are consistent with the hypothesis that in some children, epilepsy is a pervasive condition that includes both seizures and behavioral problems.

Inflammatory Markers and Incident Mobility Limitation in the Elderly

OBJECTIVES

To examine the relationship between indicators of inflammation and the incidence of mobility limitation in older persons.

DESIGN

Prospective cohort study: the Health, Aging and Body Composition Study.

SETTING

Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

A total of 2,979 men and women, aged 70 to 79, without mobility limitation at baseline.

MEASUREMENTS

Serum levels of interleukin (IL)-6, tumor necrosis factor alpha (TNFalpha), and C-reactive protein (CRP) and soluble cytokine receptors (IL-2sR, IL-6sR, TNFsR1, TNFsR2) were measured. Mobility limitation was assessed and defined as reporting difficulty or inability to walk one-quarter of a mile or to climb 10 steps during two consecutive semiannual assessments over 30 months.

RESULTS

Of the 2,979 participants, 30.1% developed incident mobility limitation. After adjustment for confounders (demographics, prevalent conditions at baseline, body composition), the relative risk (RR) of incident mobility limitation per standard deviation (SD) increase was 1.19 (95% confidence interval (CI)=1.10-1.28) for IL-6, 1.20 (95% CI=1.12-1.29) for TNFalpha, and 1.40 (95% CI=1.18-1.68) for CRP. The association between inflammation and incident mobility limitation was especially strong for the onset of more severe mobility limitation and when the levels of multiple inflammatory markers were high. When persons with baseline or incident cardiovascular disease events or persons who were hospitalized during study follow-up were excluded, findings remained similar. In a subset (n=499), high levels of the soluble receptors IL2sR and TNFsR1 (per SD increase: RR=1.23 (95% CI=1.04-1.46) and RR=1.28 (95% CI=1.04-1.57), respectively) were also associated with incident mobility limitation.

CONCLUSION

Findings suggest that inflammation is prognostic for incident mobility limitation over 30 months, independent of cardiovascular disease events and incident severe illness.

A complementary approach to promoting professionalism: identifying, measuring, and addressing unprofessional behaviors

Vanderbilt University School of Medicine (VUSM) employs several strategies for teaching professionalism. This article, however, reviews VUSM's alternative, complementary approach: identifying, measuring, and addressing unprofessional behaviors. The key to this alternative approach is a supportive infrastructure that includes VUSM leadership's commitment to addressing unprofessional/disruptive behaviors, a model to guide intervention, supportive institutional policies, surveillance tools for capturing patients' and staff members' allegations, review processes, multilevel training, and resources for addressing disruptive behavior.Our model for addressing disruptive behavior focuses on four graduated interventions: informal conversations for single incidents, nonpunitive "awareness" interventions when data reveal patterns, leader-developed action plans if patterns persist, and imposition of disciplinary processes if the plans fail. Every physician needs skills for conducting informal interventions with peers; therefore, these are taught throughout VUSM's curriculum. Physician leaders receive skills training for conducting higher-level interventions. No single strategy fits every situation, so we teach a balance beam approach to understanding and weighing the pros and cons of alternative intervention-related communications. Understanding common excuses, rationalizations, denials, and barriers to change prepares physicians to appropriately, consistently, and professionally address the real issues. Failing to address unprofessional behavior simply promotes more of it. Besides being the right thing to do, addressing unprofessional behavior can yield improved staff satisfaction and retention, enhanced reputation, professionals who model the curriculum as taught, improved patient safety and risk-management experience, and better, more productive work environments.

Psychoactive drugs and the risk of injurious motor vehicle crashes in elderly drivers

To determine whether commonly used psychoactive drugs increase the risk of involvement in motor vehicle crashes for drivers > or = 65 years of age, the authors conducted a retrospective cohort study. Data were obtained from computerized files from the Tennessee Medicaid program, driver's license files, and police reports of injurious crashes. Cohort members were Medicaid enrollees 65-84 years of age who had a valid driver's license during the study period 1984-1988 and who met other criteria designed to exclude persons unlikely to be drivers and to ensure availability of necessary study data. There were 16,262 persons in the study cohort with 38,701 person-years of follow-up and involvement in 495 injurious crashes. For four groups of psychoactive drugs (benzodiazepines, cyclic antidepressants, oral opioid analgesics, and antihistamines), the risk of crash involvement was calculated with Poisson regression models that controlled for demographic characteristics and use of medical care as an indicator of health status. The relative risk of injurious crash involvement for current users of any psychoactive drug was 1.5 (95% confidence interval (CI) 1.2-1.9). This increased risk was confined to benzodiazepines (relative risk = 1.5; 95% CI 1.2-1.9) and cyclic antidepressants (relative risk = 2.2; 95% CI 1.3-3.5). For these drugs, the relative risk increased with dose and was substantial for high doses: 2.4 (95% CI 1.3-4.4) for > or = 20 mg of diazepam and 5.5 (95% CI 2.6-11.6) for > or = 125 mg of amitriptyline. Analysis of data for the crash-involved drivers suggested that these findings were not due to confounding by alcohol use or driving frequency.

Acidobacteria phylum sequences in uranium-contaminated subsurface sediments greatly expand the known diversity within the phylum

The abundance and composition of bacteria of the phylum Acidobacteria were surveyed in subsurface sediments from uranium-contaminated sites using amplification of 16S rRNA genes followed by clone/sequence analysis. Analysis of sequences from this study and public databases produced a revised and greatly expanded phylogeny of the Acidobacteria phylum consisting of 26 subgroups.

An outbreak of Legionnaires' disease associated with a contaminated air-conditioning cooling tower

In August and September 1978, an outbreak of Legionnaires' disease occurred in Memphis, Tennessee. Of the 44 ill, 39 had been either patients, employees, visitors, or passers-by at one Memphis hospital (Hospital A) during the 10 days before. Assuming an incubation period of between two and 10 days, the onset of cases correlated precisely with the use of Hospital A's auxiliary air-conditioning cooling tower. L. pneumophila was recovered from two samples of water from the tower. Infection appeared to have occurred both outside and within the hospital. A significant association was demonstrated between acquisition of Legionnaires' disease and prior hospitalization in those areas of Hospital A that received ventilating air from air intakes near the auxiliary cooling tower. Tracer-smoke studies indicated that contaminated aerosols from the tower could easily reach these air intakes, as well as the street below, where four passers-by had been before they contracted Legionnaires' disease. This represents a common-source outbreak in which the source of L. pneumophila infection and airborne transmission were identified.

The effects of organizational climate and interorganizational coordination on the quality and outcomes of children's service systems

OBJECTIVE

This study examines the effects of organizational characteristics, including organizational climate and interorganizational coordination, on the quality and outcomes of children's service systems.

METHOD

A quasi-experimental, longitudinal design was used to assess the effects of increasing interorganizational services coordination in public children's service agencies. The research team collected both qualitative and quantitative data over a 3-year period describing the services provided to 250 children by 32 public children's service offices in 24 counties in Tennessee.

RESULTS

Findings show that organizational climate (including low conflict, cooperation, role clarity, and personalization) is the primary predictor of positive service outcomes (the children's improved psychosocial functioning) and a significant predictor of service quality. In contrast, interorganizational coordination had a negative effect on service quality and no effect on outcomes.

CONCLUSIONS

Efforts to improve public children's service systems should focus on creating positive organizational climates rather than on increasing interorganizational services coordination. This is important because many large-scale efforts to improve children's service systems have focused on interorganizational coordination with little success and none to date have focused on organizational climate.

Early physical abuse and later violent delinquency: a prospective longitudinal study

In this prospective longitudinal study of 574 children followed from age 5 to age 21, the authors examine the links between early physical abuse and violent delinquency and other socially relevant outcomes during late adolescence or early adulthood and the extent to which the child's race and gender moderate these links. Analyses of covariance indicated that individuals who had been physically abused in the first 5 years of life were at greater risk for being arrested as juveniles for violent, nonviolent, and status offenses. Moreover, physically abused youth were less likely to have graduated from high school and more likely to have been fired in the past year, to have been a teen parent, and to have been pregnant or impregnated someone in the past year while not married. These effects were more pronounced for African American than for European American youth and somewhat more pronounced for females than for males.

The Collaborative Cross at Oak Ridge National Laboratory: developing a powerful resource for systems genetics

Complex traits and disease comorbidity in humans and in model organisms are the result of naturally occurring polymorphisms that interact with each other and with the environment. To ensure the availability of resources needed to investigate biomolecular networks and systems-level phenotypes underlying complex traits, we have initiated breeding of a new genetic reference population of mice, the Collaborative Cross. This population has been designed to optimally support systems genetics analysis. Its novel and important features include a high level of genetic diversity, a large population size to ensure sufficient power in high-dimensional studies, and high mapping precision through accumulation of independent recombination events. Implementation of the Collaborative Cross has been ongoing at the Oak Ridge National Laboratory (ORNL) since May 2005. Production has been systematically managed using a software-assisted breeding program with fully traceable lineages, performed in a controlled environment. Currently, there are 650 lines in production, and close to 200 lines are now beyond their seventh generation of inbreeding. Retired breeders enter a high-throughput phenotyping protocol and DNA samples are banked for analyses of recombination history, allele drift and loss, and population structure. Herein we present a progress report of the Collaborative Cross breeding program at ORNL and a description of the kinds of investigations that this resource will support.