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1.  Should Perioperative Supplemental Oxygen Be Routinely Recommended for Surgical Patients? A Bayesian Meta-analysis 
Annals of surgery  2012;256(6):894-901.
The purpose of this study is to use updated data and Bayesian methods to evaluate the effectiveness of hyperoxia to reduce surgical site infections (SSIs) and/or mortality in both colorectal and all surgical patients. Because few trials assessed potential harms of hyperoxia, hazards were not included.
Use of hyperoxia to reduce SSIs is controversial. Three recent meta-analyses have had conflicting conclusions.
A systematic literature search and review were performed. Traditional fixed-effect and random-effects meta-analyses and Bayesian meta-analysis were performed to evaluate SSIs and mortality.
Traditional meta-analysis yielded a relative risk of an SSI with hyperoxia among all surgery patients of 0.84 (95% confidence interval, CI, 0.73–0.97) and 0.84 (95% CI 0.61–1.16) for the fixed-effect and random effects models respectively. The probabilities of any risk reduction in SSIs among all surgery patients were 77%, 81%, and 83% for skeptical, neutral, and enthusiastic priors. Subset analysis of colorectal surgery patients increased the probabilities to 86%, 89%, and 92%. The probabilities of at least a 10% reduction were 57%, 62%, and 68% for all surgical patients and 71%, 75%, and 80% among the colorectal surgery subset.
There is a moderately high probability of a benefit to hyperoxia in reducing SSIs in colorectal surgery patients; however, the magnitude of benefit is relatively small and might not exceed treatment hazards. Further studies should focus on generalizability to other patient populations or on treatment hazards and other outcomes.
PMCID: PMC3504355  PMID: 23160100
2.  Does Aggressive Phototherapy Increase Mortality while Decreasing Profound Impairment among the Smallest and Sickest Newborns? 
Aggressive phototherapy (AgPT) is widely used and assumed to be safe and effective for even the most immature infants. We assessed whether the benefits and hazards for the smallest and sickest infants differed from those for other extremely low birth weight (ELBW; (≤1000 g) infants in our Neonatal Research Network trial, the only large trial of AgPT.
Study Design
ELBW infants (n=1974) were randomized to AgPT or conservative phototherapy at age 12–36 hours. The effect of AgPT on outcomes (death; impairment; profound impairment; death or impairment [primary outcome], and death or profound impairment) at 18–22 months corrected age was related to BW stratum (501–750 g; 751–1000 g) and baseline severity of illness using multilevel regression equations. The probability of benefit and of harm was directly assessed with Bayesian analyses.
Baseline illness severity was well characterized using mechanical ventilation and FiO2 at 24 hours age. Among mechanically ventilated infants ≤750 g BW (n =684), a reduction in impairment and in profound impairment was offset by higher mortality (p for interaction <0.05) with no significant effect on composite outcomes. Conservative Bayesian analyses of this subgroup identified a 99% (posterior) probability that AgPT increased mortality, a 97% probability that AgPT reduced impairment, and a 99% probability that AgPT reduced profound impairment.
Findings from the only large trial of AgPT suggest that AgPT may increase mortality while reducing impairment and profound impairment among the smallest and sickest infants. New approaches to reduce their serum bilirubin need development and rigorous testing.
PMCID: PMC3558278  PMID: 22652561
Phototherapy; bilirubin; severity of illness; ELBW infant; impairment; randomized clinical trial; statistical interaction; Bayesian analysis
3.  The Influence of Baseline Marijuana Use on Treatment of Cocaine Dependence: Application of an Informative-Priors Bayesian Approach 
Background: Marijuana use is prevalent among patients with cocaine dependence and often non-exclusionary in clinical trials of potential cocaine medications. The dual-focus of this study was to (1) examine the moderating effect of baseline marijuana use on response to treatment with levodopa/carbidopa for cocaine dependence; and (2) apply an informative-priors, Bayesian approach for estimating the probability of a subgroup-by-treatment interaction effect. Method: A secondary data analysis of two previously published, double-blind, randomized controlled trials provided complete data for the historical (Study 1: N = 64 placebo), and current (Study 2: N = 113) data sets. Negative binomial regression evaluated Treatment Effectiveness Scores (TES) as a function of medication condition (levodopa/carbidopa, placebo), baseline marijuana use (days in past 30), and their interaction. Results: Bayesian analysis indicated that there was a 96% chance that baseline marijuana use predicts differential response to treatment with levodopa/carbidopa. Simple effects indicated that among participants receiving levodopa/carbidopa the probability that baseline marijuana confers harm in terms of reducing TES was 0.981; whereas the probability that marijuana confers harm within the placebo condition was 0.163. For every additional day of marijuana use reported at baseline, participants in the levodopa/carbidopa condition demonstrated a 5.4% decrease in TES; while participants in the placebo condition demonstrated a 4.9% increase in TES. Conclusion: The potential moderating effect of marijuana on cocaine treatment response should be considered in future trial designs. Applying Bayesian subgroup analysis proved informative in characterizing this patient-treatment interaction effect.
PMCID: PMC3483568  PMID: 23115553
cocaine; marijuana; treatment response; Bayesian; subgroup analysis
4.  Monetary Incentive Effects on Event-Based Prospective Memory Three Months after Traumatic Brain Injury in Children 
Information regarding the remediation of event-based prospective memory (EB-PM) impairments following pediatric traumatic brain injury (TBI) is scarce. Addressing this, two levels of monetary incentives were used to improve EB-PM in children ages 7 to 16 years with orthopedic injuries (OI, n = 51), or moderate (n = 25), and severe (n = 39) TBI at approximately three months postinjury. The EB-PM task consisted of the child giving a specific verbal response to a verbal cue from the examiner while performing a battery of neuropsychological measures (ongoing task). Significant effects were found for Age-at-Test, Motivation Condition, Period, and Group. Within-group analyses indicated OI and moderate TBI groups performed significantly better under the high-versus low-incentive condition, but the severe TBI group demonstrated no significant improvement. These results indicate EB-PM can be significantly improved at three months postinjury in children with moderate, but not severe, TBI.
PMCID: PMC3123684  PMID: 21347945
Event-based prospective memory; Traumatic brain injury; Monetary Incentives; Motivation; Memory rehabilitation; Pediatrics
5.  Diffusion Tensor Imaging of Incentive Effects in Prospective Memory after Pediatric Traumatic Brain Injury 
Journal of Neurotrauma  2011;28(4):503-516.
Few studies exist investigating the brain-behavior relations of event-based prospective memory (EB-PM) impairments following traumatic brain injury (TBI). To address this, children with moderate-to-severe TBI performed an EB-PM test with two motivational enhancement conditions and underwent concurrent diffusion tensor imaging (DTI) at 3 months post-injury. Children with orthopedic injuries (OI; n = 37) or moderate-to-severe TBI (n = 40) were contrasted. Significant group differences were found for fractional anisotropy (FA) and apparent diffusion coefficient for orbitofrontal white matter (WM), cingulum bundles, and uncinate fasciculi. The FA of these WM structures in children with TBI significantly correlated with EB-PM performance in the high, but not the low motivation condition. Regression analyses within the TBI group indicated that the FA of the left cingulum bundle (p = 0.003), left orbitofrontal WM (p < 0.02), and left (p < 0.02) and right (p < 0.008) uncinate fasciculi significantly predicted EB-PM performance in the high motivation condition. We infer that the cingulum bundles, orbitofrontal WM, and uncinate fasciculi are important WM structures mediating motivation-based EB-PM responses following moderate-to-severe TBI in children.
PMCID: PMC3070141  PMID: 21250917
cingulum bundles; diffusion tensor imaging; event-based prospective memory; incentive; motivation; pediatrics orbitofrontal white matter; traumatic brain injury; uncinate fasciculus
6.  Diabetes and Reduced Risk for Thoracic Aortic Aneurysms and Dissections: A Nationwide Case-Control Study 
Vascular diseases are the principal causes of death and disability in people with diabetes. At the same time, studies suggest a protective role of diabetes in the development of abdominal aortic aneurysms. We sought to determine whether diabetes is associated with decreased hospitalization due to thoracic aortic aneurysms and dissections (TAAD).
Methods and Results
We used the 2006 and 2007 Nationwide Inpatient Sample (NIS) to determine TAAD discharge rates. Control subjects were randomly selected to achieve three controls per case. Predictor variables in multilevel logistic regression included age, race, median income, diabetes, and hypertension. We estimated that the average rate of hospital discharge for TAAD among individuals diagnosed with diabetes was 9.7 per 10 000, compared to 15.6 per 10 000 among all discharges. The prevalence of diabetes was substantially lower in TAAD (13%) than in control (22%) records. After adjustment for demographic characteristics, the negative association between diabetes and TAAD remained highly significant in both NIS datasets. Compared to discharges without diabetes, those with chronic complications of diabetes were least likely to be diagnosed with TAAD (OR [odds ratio] 0.17, 95% CI, 0.12–0.23). A significant association remained between uncomplicated diabetes and TAAD. We replicated these findings in an independent group of patients who were hospitalized with acute thoracic aortic dissections.
The principal implication of our findings is that diabetes is independently associated with a decreased rate of hospitalization due to TAAD in proportion to the severity of diabetic complications. Future studies should consider diabetes in predictive models of aneurysm expansion or dissection. (J Am Heart Assoc. 2012;1:jah3-e000323 doi: 10.1161/JAHA.111.000323.)
PMCID: PMC3487378  PMID: 23130125
aorta; aneurysm; diabetes mellitus; risk factors; epidemiology
7.  The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI): I. Construct Validity 
Journal of Neurotrauma  2010;27(6):983-989.
The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) is a measure adapted from the National Institutes of Health Stroke Scale (NIHSS), and is intended to capture essential neurological deficits impacting individuals with traumatic brain injury (TBI) (see Wilde et al., 2010). In the present study we evaluate the measure's construct validity via comparison with a quantified neurological examination performed by a neurologist. Spearman rank-order correlation between the NOS-TBI and the neurological examination was ρ = 0.76, p < 0.0001, suggesting a high degree of correspondence (construct validity) between these two measures of neurological function. Additionally, items from the NOS-TBI compared favorably to the neurological examination items, with correlations ranging from 0.60 to 0.99 (all p < 0.0001). On formal neurological examination, some degree of neurological impairment was observed in every participant in this cohort of individuals undergoing rehabilitation for TBI, and on the NOS-TBI neurological impairment was evident in all but one participant. This study documents the presence of measurable neurological sequelae in a sample of patients with TBI in a post-acute rehabilitation setting, underscoring the need for formal measurement of the frequency and severity of neurological deficits in this population. The results suggest that the NOS-TBI is a valid measure of neurological functioning in patients with TBI.
PMCID: PMC2943496  PMID: 20210594
Neurological Outcome Scale for Traumatic Brain Injury; outcome; traumatic brain injury; validity
8.  The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI): II. Reliability and Convergent Validity 
Journal of Neurotrauma  2010;27(6):991-997.
A standardized measure of neurological dysfunction specifically designed for TBI currently does not exist and the lack of assessment of this domain represents a substantial gap. To address this, the Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) was developed for TBI outcomes research through the addition to and modification of items specifically relevant to patients with TBI, based on the National Institutes of Health Stroke Scale. In a sample of 50 participants (mean age = 33.3 years, SD = 12.9) ≤18 months (mean = 3.1, SD = 3.2) following moderate (n = 8) to severe (n = 42) TBI, internal consistency of the NOS-TBI was high (Cronbach's alpha = 0.942). Test-retest reliability also was high (ρ = 0.97, p < 0.0001), and individual item kappas between independent raters were excellent, ranging from 0.83 to 1.0. Overall inter-rater agreement between independent raters (Kendall's coefficient of concordance) for the NOS-TBI total score was excellent (W = 0.995). Convergent validity was demonstrated through significant Spearman rank-order correlations between the NOS-TBI and the concurrently administered Disability Rating Scale (ρ = 0.75, p < 0.0001), Rancho Los Amigos Scale (ρ = −0.60, p < 0.0001), Supervision Rating Scale (ρ = 0.59, p < 0.0001), and the FIM™ (ρ = −0.68, p < 0.0001). These results suggest that the NOS-TBI is a reliable and valid measure of neurological functioning in patients with moderate to severe TBI.
PMCID: PMC2943498  PMID: 20210595
convergent validity; Neurological Outcome Scale for Traumatic Brain Injury; outcome; reliability; traumatic brain injury
9.  Feasibility of the Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) in Adults 
Journal of Neurotrauma  2010;27(6):975-981.
This article describes the design and initial implementation of the Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) as an adaptation of the National Institutes of Health Stroke Scale (NIHSS), specifically for clinical and research use in patients with TBI, including (1) the addition of items specific to TBI, (2) adjustment to the scoring algorithm to allow quantification of deficits in patients who are comatose/vegetative or agitated, and (3) the reassignment of items (i.e., limb ataxia) that are problematic in TBI as supplemental items. The feasibility of using the NOS-TBI is discussed and limitations of the scale are highlighted. This scale offers (1) a cost-effective, brief, practicable, standardized, and quantifiable method of communicating and analyzing neurological deficits in a way that traditional neurological assessment alone cannot currently provide, and (2) a measure that non-physicians can administer. The NOS-TBI may serve a role in clinical practice in patients with TBI similar to the way the NIHSS has functioned for patients following stroke, by serving as a tool for initial stratification of injury severity, and as an outcome measure in clinical trials.
PMCID: PMC2943506  PMID: 20210593
neurological functioning; Neurological Outcome Scale for Traumatic Brain Injury; outcome; traumatic brain injury
10.  Incentive Effects on Event-Based Prospective Memory Performance in Children and Adolescents with Traumatic Brain Injury 
Neuropsychology  2009;23(2):201-209.
Prospective memory (PM) is the formation of an intention and remembering to perform this intention at a future time or in response to specific cues. PM tasks are a ubiquitous part of daily life. Currently, there is a paucity of information regarding PM impairments in children with traumatic brain injury (TBI) and less empirical evidence regarding effective remediation strategies to mitigate these impairments. The present study employed two levels of a motivational enhancement (i.e., a monetary incentive) to determine if event-based PM could be improved in children with severe TBI. In a cross-over design, children with orthopedic injuries and mild or severe TBI were compared on two levels of incentive (dollars versus pennies) given in response to accurate performance. All three groups performed significantly better under the high- versus low-motivation conditions. However, the severe TBI group’s high-motivation condition performance remained significantly below the low-motivation condition performance of the orthopedic injury group. PM scores were positively and significantly related to age-attest, but there were no age-at-injury or time-postinjury effects. Overall, these results suggest that event-based PM can be significantly improved in children with severe TBI.
PMCID: PMC3068556  PMID: 19254093
Event-based prospective memory; Traumatic brain injury; Incentive; Motivation; Memory rehabilitation
11.  Aggressive vs. Conservative Phototherapy for Infants with Extremely Low Birth Weight 
It is unclear whether aggressive phototherapy to prevent neurotoxic effects of bilirubin benefits or harms infants with extremely low birth weight (1000 g or less).
We randomly assigned 1974 infants with extremely low birth weight at 12 to 36 hours of age to undergo either aggressive or conservative phototherapy. The primary outcome was a composite of death or neurodevelopmental impairment determined for 91% of the infants by investigators who were unaware of the treatment assignments.
Aggressive phototherapy, as compared with conservative phototherapy, significantly reduced the mean peak serum bilirubin level (7.0 vs. 9.8 mg per deciliter [120 vs. 168 μmol per liter], P<0.01) but not the rate of the primary outcome (52% vs. 55%; relative risk, 0.94; 95% confidence interval [CI], 0.87 to 1.02; P = 0.15). Aggressive phototherapy did reduce rates of neurodevelopmental impairment (26%, vs. 30% for conservative phototherapy; relative risk, 0.86; 95% CI, 0.74 to 0.99). Rates of death in the aggressive-phototherapy and conservative-phototherapy groups were 24% and 23%, respectively (relative risk, 1.05; 95% CI, 0.90 to 1.22). In preplanned subgroup analyses, the rates of death were 13% with aggressive phototherapy and 14% with conservative phototherapy for infants with a birth weight of 751 to 1000 g and 39% and 34%, respectively (relative risk, 1.13; 95% CI, 0.96 to 1.34), for infants with a birth weight of 501 to 750 g.
Aggressive phototherapy did not significantly reduce the rate of death or neurodevelopmental impairment. The rate of neurodevelopmental impairment alone was significantly reduced with aggressive phototherapy. This reduction may be offset by an increase in mortality among infants weighing 501 to 750 g at birth. (ClinicalTrials. gov number, NCT00114543.)
PMCID: PMC2821221  PMID: 18971491

Results 1-11 (11)