Meta-analysis of clinical trials in the 2020s and beyond: a paradigm shift needed

Background

A peer-reviewed meta-analysis methods article mathematically proved that mainstream random-effects methods, "weights inversely proportional to the estimated variance," are flawed and can lead to faulty public health recommendations. Because the arguments causing this off-label (unproven) use of mainstream practices were subtle, changing these practices will require much clearer explanations that can be grasped by clinical and translational scientists. There are five assumptions underlying the mainstream's derivation of its statistical properties. This paper will demonstrate that if the first is true, it follows that the last two are false. Ratio estimation, borrowed from classical survey sampling, provides a rigorous alternative. Papers reporting results rarely fully disclose these assumptions. This is analogous to watching TV ads with the sound muted. You see high quality of life and do not hear about the complications. This article is a poster child for translational science, as it takes a theoretical discovery from the biostatistical world, translates it into language clinical scientists can understand, and thereby can change their research practice.

Aim

This article is aimed at future applications of meta-analysis of complete collections of randomized clinical trials. It leaves it to past authors as to whether to reanalyze their data. No blame for past use is assessed.

Methods

By treating the individual completed studies in the meta-analysis as a random sample from a conceptual universe of completed studies, we use ratio estimation to obtain estimates of relative risk (ratio of failure rates treatment: control) and mean differences, projecting our sample value to estimate the universe's value.

Results

Two examples demonstrate that the mainstream methods likely adversely impacted major treatment options. A third example shows that the key mainstream presumption of independence between the study weights and study estimates cannot be supported.

Conclusion

There is no rationale for ever using the mainstream for meta-analysis of randomized clinical trials.

Relevance for Patients

Future meta-analysis of clinical trials should never employ mainstream methods. Doing so could lead to potentially harmful public health policy recommendations. Clinical researchers need to play a primary role to assure good research practices in meta-analysis.

Medication Use for ADHD and the Risk of Driving Citations and Crashes Among Teenage Drivers: A Population-Based Cohort Study

Objectives: To evaluate the real-world effectiveness of ADHD medications on adverse driving outcomes in teenage drivers with ADHD. Method: We retrospectively followed 15- to 20-year-old ADHD patients with valid driver's license to compare the risk for crashes and citations between periods with and without ADHD medication use, using Florida Medicaid records linked to Department of Motor Vehicles data from 1999 to 2004. Patient-level demographic, clinical, and driver licensing characteristics as well as county-level crash and traffic statistics were adjusted in Cox models. Results: A total of 2,049 patients had 67 crashes and 319 citations. Adjusted hazard ratios comparing ADHD medication use versus no use were 1.22 (95% confidence interval [CI] = [0.66, 1.90]) and 0.89 (95% CI = [0.69, 1.13]) for crashes and citations, respectively. Conclusion: Our study showed no evidence that ADHD medication use was associated with a reduced risk of adverse driving outcomes among teenage drivers enrolled in Medicaid programs. Limitations in interpreting this finding are presented.

Elevated serum insulin-like growth factor 1 in recurrent aphthous stomatitis

Over 100 million Americans experience recurrent aphthous stomatitis (RAS) at some point in life. To develop targeted drugs for RAS treatment, it is critical to identify its etiology. We determined if serum insulin‐like growth factor 1 (IGF‐1) and related factors are associated with RAS, because both RAS prevalence and IGF‐1 are highest during puberty. We analyzed data from 1,480 Third National Health and Nutrition Examination Survey participants aged 20–40 years. Participants with a history of diabetes or lupus, cotinine levels 6 ng/ml or higher or glycemia 110 mg/dl or higher were excluded. We compared levels of IGF‐1, IGFBP‐3, leptin, and insulin in participants with a positive vs. negative RAS history in the prior 12 months. We used logistic regression in SAS/SUDAAN to account for the complex sampling design. The odds of a positive RAS history were 1.31 times higher for every 100 ng/ml increase in serum IGF‐1. This association persisted after adjustment for age, race/ethnicity, medication intake, body mass index, insulin, leptin, glycemia, and income (adjusted OR = 1.30, 95% CI [1.06, 1.60]; p = 0.013). The odds of a positive RAS history were also higher among non‐Hispanic white compared with non‐Hispanic black participants (adjusted OR = 4.37, 95% CI [3.00, 6.38]). Leptin, IGFBP‐3, and insulin levels did not differ by RAS status. The significantly higher IGF‐1 levels in participants with a positive RAS history compared with controls suggest a possible role of the IGF‐1 pathway in RAS etiology.

Web-based Health Information Seeking and eHealth Literacy among Patients Living with Chronic Obstructive Pulmonary Disease (COPD)

Many people living with Chronic Obstructive Pulmonary Disease (COPD) have low general health literacy; however, there is little information available on these patients' eHealth literacy, or their ability to seek, find, understand, and appraise online health information and apply this knowledge to address or solve disease-related health concerns. A nationally representative sample of patients registered in the COPD Foundation's National Research Registry (N = 1,270) was invited to complete a web-based survey to assess socio-demographic (age, gender, marital status, education), health status (generic and lung-specific health-related quality of life), and socio-cognitive (social support, self-efficacy, COPD knowledge) predictors of eHealth literacy, measured using the 8-item eHealth literacy scale (eHEALS). Over 50% of the respondents (n = 176) were female (n = 89), with a mean age of 66.19 (SD = 9.47). Overall, participants reported moderate levels of eHealth literacy, with more than 70% feeling confident in their ability to find helpful health resources on the Internet. However, respondents were much less confident in their ability to distinguish between high- and low-quality sources of web-based health information. Very severe versus less severe COPD (β = 4.15), lower lung-specific health-related quality of life (β = -0.19), and greater COPD knowledge (β = 0.62) were significantly associated with higher eHealth literacy. Higher COPD knowledge was also significantly associated with greater knowledge (ρ = 0.24, p = .001) and use (ρ = 0.24, p = .001) of web-based health resources. Findings emphasize the importance of integrating skill-building activities into comprehensive patient education programs that enable patients with severe cases of COPD to identify high-quality sources of web-based health information. Additional research is needed to understand how new social technologies can be used to help medically underserved COPD patients benefit from web-based self-management support resources.

Adding electrical stimulation during standard rehabilitation after stroke to improve motor function. A systematic review and meta-analysis

BACKGROUND

Clinical studies have shown that sensory input improves motor function when added to active training after neurological injuries in the spinal cord.

OBJECTIVE

We aimed to determine the effect on motor function of extremities of adding an electrical sensory modality without motor recruitment before or with routine rehabilitation for hemiparesis after stroke by a comprehensive systematic review and meta-analysis.

METHODS

We searched databases including MEDLINE via PubMed and the Cochrane Central Register of Controlled Trials from 1978 to the end of November 2017 for reports of randomized controlled trials or controlled studies of patients with a clinical diagnosis of stroke who underwent 1) transcutaneous electrical nerve stimulation (TENS) or peripheral electromyography-triggered sensory stimulation over a peripheral nerve and associated muscles or 2) acupuncture to areas that produced sensory effects, without motor recruitment, along with routine rehabilitation. Outcome measures were motor impairment, activity, and participation outcomes defined by the International Classification of Functioning, Disability and Health.

RESULTS

The search yielded 11studies with data that could be included in a meta-analysis. Electrical sensory inputs, when paired with routine therapy, improved peak torque dorsiflexion (mean difference [MD] 2.44 Nm, 95% confidence interval [CI] 0.26-4.63). On subgroup analysis, the combined therapy yielded a significant difference in terms of sensory stimulation without motor recruitment only on the Timed Up and Go test in the chronic phase of stroke (MD 3.51sec, 95% CI 3.05-3.98). The spasticity score was reduced but not significantly (MD-0.83 points, 95% CI -1.77-0.10).

CONCLUSION

Electrical sensory input can contribute to routine rehabilitation to improve early post-stroke lower-extremity impairment and late motor function, with no change in spasticity. Prolonged periods of sensory stimulation such as TENS combined with activity can have beneficial effects on impairment and function after stroke.

Linear combinations come alive in crossover designs

Before learning anything about statistical inference in beginning service courses in biostatistics, students learn how to calculate the mean and variance of linear combinations of random variables. Practical precalculus examples of the importance of these exercises can be helpful for instructors, the target audience of this paper. We shall present applications to the "1-sample" and "2-sample" methods for randomized short-term 2-treatment crossover studies, where patients experience both treatments in random order with a "washout" between the active treatment periods. First, we show that the 2-sample method is preferred as it eliminates "conditional bias" when sample sizes by order differ and produces a smaller variance. We also demonstrate that it is usually advisable to use the differences in posttests (ignoring baseline and post washout values) rather than the differences between the changes in treatment from the start of the period to the end of the period ("delta of delta"). Although the intent is not to provide a definitive discussion of crossover designs, we provide a section and references to excellent alternative methods, where instructors can provide motivation to students to explore the topic in greater detail in future readings or courses.

Comparing glaucomatous disc change using stereo disc viewing and the MatchedFlicker programme in glaucoma experts and trainees

BACKGROUND/AIMS

The objective of this study is to evaluate the accuracy and speed of trainees and experienced glaucoma specialists using the MatchedFlicker software against the manual examination of stereoscopic disc photographs for detecting glaucomatous optic disc change.

METHODS

Three experienced glaucoma specialists, two resident ophthalmologists and one glaucoma fellow from multiple institutions independently evaluated the same 140 image pairs from 100 glaucomatous/ocular hypertensive eyes using a handheld stereo viewer and the MatchedFlicker programme. Fifty had progression to glaucoma as determined by the Ocular Hypertension Treatment Study (OHTS) Optic Disc Reading Group and endpoint committee, and 50 more were negative controls for progression with photos taken a few minutes apart. Twenty photo pairs from each of the two groups were duplicated for reviewer variability analysis. The initial viewing method was randomised and then alternated for each group of 70 image pairs. Reviewer accuracy and evaluation time for each method were measured.

RESULTS

Evaluators averaged 8.6 s faster per image pair (26%) with the MatchedFlicker programme than with the stereo viewer (p=0.0007). Evaluators correctly identified more image pairs when using the MatchedFlicker software over the stereo viewer (p=0.0003). There was no significant difference between the expert and trainee group in speed or overall accuracy for either method. Experts were significantly more consistent than trainees with the duplicate image pairs (p=0.029). Trainees appeared more reluctant to designate eyes as showing glaucoma progression than experts.

CONCLUSIONS

Both expert glaucoma specialists and ophthalmologists in various stages of training had greater accuracy and speed with the MatchedFlicker programme than with a handheld stereoscopic viewer.

Premeal insulin decreases arterial stiffness in children with type 1 diabetes

OBJECTIVE

To determine the effects of omitting meal time insulin on arterial stiffness in children with type 1 diabetes.

RESEARCH DESIGN AND METHODS

In this prospective, randomized, crossover study, radial artery tonometry and augmentation index adjusted to heart rate 75 (AI₇₅ ) were used to measure arterial stiffness. Children were randomized to receive or omit premeal insulin and completed the crossover portion of the study on a subsequent day. AI₇₅ was determined when fasting, 1, and 2 h postmeal.

RESULTS

When comparing change in AI₇₅ from baseline to 1 h and baseline to 2 h, when subjects received premeal insulin vs. no insulin, AI₇₅ was 4.5 units lower at 1 h (p = 0.011, 95% CI:1.1 lower to 8 lower) and 4.3 units lower at 2 h (p = 0.062, 95% CI: 0.2 higher to 8.9 lower) (n = 40).

CONCLUSIONS

Arterial stiffness is decreased by premeal insulin in children with type 1 diabetes.

Peripheral Blood Cytokine Levels After Acute Myocardial Infarction: IL-1β- and IL-6-Related Impairment of Bone Marrow Function

RATIONALE

Intracoronary infusion of bone marrow (BM) mononuclear cells after acute myocardial infarction (AMI) has led to limited improvement in left ventricular function. Although experimental AMI models have implicated cytokine-related impairment of progenitor cell function, this response has not been investigated in humans.

OBJECTIVE

To test the hypothesis that peripheral blood (PB) cytokines predict BM endothelial progenitor cell colony outgrowth and cardiac function after AMI.

METHODS AND RESULTS

BM and PB samples were collected from 87 participants 14 to 21 days after AMI and BM from healthy donors was used as a reference. Correlations between cytokine concentrations and cell phenotypes, cell functions, and post-AMI cardiac function were determined. PB interleukin-6 (IL-6) negatively correlated with endothelial colony-forming cell colony maximum in the BM of patients with AMI (estimate±SE, -0.13±0.05; P=0.007). BM from healthy individuals showed a dose-dependent decrease in endothelial colony-forming cell colony outgrowth in the presence of exogenous IL-1β or IL-6 (P<0.05). Blocking the IL-1R or IL-6R reversed cytokine impairment. In AMI study participants, the angiogenic cytokine platelet-derived growth factor BB glycoprotein correlated positively with BM-derived colony-forming unit-endothelial colony maximum (estimate±SE, 0.01±0.002; P<0.001), multipotent mesenchymal stromal cell colony maximum (estimate±SE, 0.01±0.002; P=0.002) in BM, and mesenchymal stromal cell colony maximum in PB (estimate±SE, 0.02±0.005; P<0.001).

CONCLUSIONS

Two weeks after AMI, increased PB platelet-derived growth factor BB glycoprotein was associated with increased BM function, whereas increased IL-6 was associated with BM impairment. Validation studies confirmed inflammatory cytokine impairment of BM that could be reversed by blocking IL-1R or IL-6R. Together, these studies suggest that blocking IL-1 or IL-6 receptors may improve the regenerative capacity of BM cells after AMI.

CLINICAL TRIAL REGISTRATIONS

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00684060.

A Patient-Centered Emergency Department Management Strategy for Sickle-Cell Disease Super-Utilizers

Introduction

A subpopulation of sickle-cell disease patients, termed super-utilizers, presents frequently to emergency departments (EDs) for vaso-occlusive events and may consume disproportionate resources without broader health benefit. To address the healthcare needs of this vulnerable patient population, we piloted a multidisciplinary intervention seeking to create and use individualized patient care plans that alter utilization through coordinated care. Our goals were to assess feasibility primarily, and to assess resource use secondarily.

Methods

We evaluated the effects of a single-site interventional study targeted at a population of adult sickle-cell disease super-utilizers using a pre- and post-implementation design. The pre-intervention period was 06/01/13 to 12/31/13 (seven months) and the post-intervention period was 01/01/14 to 02/28/15 (14 months). Our approach included patient-specific best practice advisories (BPA); an ED management protocol; and formation of a “medical home” for these patients.

Results

For 10 subjects targeted initially we developed and implemented coordinated care plans; after deployment, we observed a tendency toward reduction in ED and inpatient utilization across all measured indices. Between the annualized pre- and post-implementation periods we found the following: ED visits decreased by 16.5 visits/pt-yr (95% confidence interval [CI] [−1.32–34.2]); ED length of state (LOS) decreased by 115.3 hours/pt-yr (95% CI [−82.9–313.5]); in-patient admissions decreased by 4.20 admissions/pt-yr (95% CI [−1.73–10.1]); in-patient LOS decreased by 35.8 hours/pt-yr (95% CI [−74.9–146.7]); and visits where the patient left before treatment were reduced by an annualized total of 13.7 visits. We observed no patient mortality in our 10 subjects, and no patient required admission to the intensive care unit 72 hours following discharge.

Conclusion

This effort suggests that a targeted approach is both feasible and potentially effective, laying a foundation for broader study.

Therapeutic hypothermia for neonatal hypoxic ischemic encephalopathy is associated with short-term reduction of seizures after discharge from the neonatal intensive care unit

INTRODUCTION

Therapeutic hypothermia for the treatment of moderate to severe neonatal hypoxic ischemic encephalopathy has been shown to reduce death and disability, but the effects on seizures after discharge from the Neonatal ICU are not known.

METHODS

A retrospective cohort study was conducted involving 56 neonates admitted to the Neonatal ICU at Children's Hospital of Orange County, CA from January 1, 2007 to September 1, 2013 with hypoxic ischemic encephalopathy who met criteria for selective brain cooling. Fifteen patients received supportive care. Forty-one patients received cooling, of whom 25 were included for analysis. Sixteen patients from the hypothermia group and 12 from the no hypothermia group developed clinical seizures while inpatient. Up to 6 months, four patients (16%) had continued seizures in the therapeutic hypothermia group compared to eight (53%) patients who did not receive hypothermia.

DISCUSSION

Our study shows an association between therapeutic hypothermia and reduced seizures after discharge from the neonatal intensive care unit. The short duration of follow-up, 6 months, is a limitation of this study. Another limitation is its observational nature, where reasons for treatment selection and exclusions are unmeasurable confounding factors. Further studies are needed to determine long-term effects.

Efficacy and retention of Basic Life Support education including Automated External Defibrillator usage during a physical education period

The American Heart Association (AHA) advocates for CPR education as a requirement of secondary school curriculum. Unfortunately, many states have not adopted CPR education. Our aim was to investigate a low-cost, time effective method to educate students on Basic Life Support (BLS), including reeducation. This is a prospective, randomized study. Retention was assessed at 4 months post-initial education. Education was performed by AHA-certified providers during a 45-minute physical education class in a middle school in Florida. This age provides opportunities for reinforcement through high school, with ability for efficient learning. The study included 41 Eighth grade students. Students were randomized into two groups; one group received repeat education 2 months after the first education, the second group did not. All students received BLS education limited to chest compressions and usage of an Automated External Defibrillator. Students had skills and knowledge tests administered pre- and post-education after initial education, and repeated 2 and 4 months later to assess retention. There was a significant increase in CPR skills and knowledge when comparing pre- and post-education results for all time-points (p < 0.001). When assessing reeducation, a significant improvement was noted in total knowledge scores but not during the actual steps of CPR. Our study indicates significant increase in CPR knowledge and skills following a one-time 45-minute session. Reeducation may be useful, but the interval needs further investigation. If schools across the United States invested one 45–60-minute period every school year, this would ensure widespread CPR knowledge with minimal cost and loss of school time.

•

School age children can efficiently learn Basic Life Support in one physical education period.

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Middle school students show good CPR knowledge and skills retention 2 and 4 months post-education,

•

Middle school students can effectively learn the use of an Automated External Defibrillator.

•

Basic Life Support education can change the attitude of middle school students towards CPR.

•

Reeducation may improve CPR knowledge, skills and Automated External Defibrillator use.

The effect of EHR-integrated patient-reported outcomes on satisfaction with chronic pain care

OBJECTIVES

Given its complexity, chronic noncancer pain presents an opportunity to use health information technology (IT) to improve care experiences. The objective of this study was to assess whether integrating patient-reported outcomes (PROs) data in an electronic health record (EHR) affects provider and patient satisfaction with chronic noncancer pain care.

STUDY DESIGN

We conducted a pragmatic cluster randomized trial involving 4 family medicine clinics.

METHODS

We enrolled primary care providers (PCPs) and their patients with chronic noncancer pain. In the first 7 months (education phase), PCPs in intervention practices received education on how to use PROs for pain care. In the second 7 months (PRO phase), patients in intervention practices reported pain-related outcomes on arrival at their visits. PROs were immediately reported to PCPs through the EHR. Control group PCPs provided usual care. We compared intervention and control practices in terms of provider and patient satisfaction with care.

RESULTS

During the education phase, patients' mean ratings of their visits did not differ between control and intervention (9.33 vs 9.08; P = .20). During the PRO phase, patients' mean ratings did not differ between control and intervention (9.28 vs 9.01; P = .20). Similarly, there were no differences between the intervention and control groups in terms of provider satisfaction.

CONCLUSIONS

Delivering EHR-integrated PROs did not consistently improve patient or provider satisfaction. Positively, we found no evidence that the PRO tools negatively affected satisfaction. Future studies and technological innovations are needed to translate point-of-care health IT tools into improvements in patient and provider experiences.

Does carbon dioxide insufflation impact adenoma detection rate? A single-center retrospective analysis

Background and study aims: Carbon dioxide (CO₂) has been associated with reduced post-procedural pain and improved patient satisfaction when compared to air insufflation (AI). The effect of CO₂ insufflation (CO₂I) on the adenoma detection rate (ADR) remains unclear. The aims of this study are to compare ADR in patients undergoing screening colonoscopy with AI vs. CO₂I and identify predictors of ADR. Patients and methods: Single-center retrospective cohort study of 2,107 patients undergoing screening colonoscopy at the University of Florida Hospital between November 2011 and June 2015. Patient demographics, procedural parameters, and histology results were retrospectively obtained from a prospectively maintained colonoscopy database. Univariate and multivariate analysis were performed to identify predictors of ADR. Results: A total of 2107 colonoscopies (644 with AI and 1463 with CO₂I) were analyzed. Overall ADR was 27.8 %. There was no significant difference in ADR between AI (27.6 %) vs. CO₂I (27.8 %) (P = 0.93). Method of insufflation (AI vs. CO₂I) was not significantly associated with ADR (OR 0.9; 95 % CI:0.7 - 1.2). Older age (OR: 1.02; 95 % CI: 1.001 - 1.03 per year increase), male gender (OR 1.48; 95 % CI: 1.17 - 1.87), and longer scope withdraw time (OR 1.13; 95 % CI: 1.1 - 1.16 per minute) were associated with a higher ADR. Fellow involvement was negatively associated with ADR (OR 0.60; 95 % CI: 0.47 - 0.77). Conclusion: ADR was similar between patients who underwent screening colonoscopy with AI vs. CO₂I. While CO₂I has been associated with improved patient comfort and post-procedural recovery time, there is no definitive evidence to suggest that this method of luminal distention enhances ADR.

Antithymocyte Globulin Plus G-CSF Combination Therapy Leads to Sustained Immunomodulatory and Metabolic Effects in a Subset of Responders With Established Type 1 Diabetes

Low-dose antithymocyte globulin (ATG) plus pegylated granulocyte colony-stimulating factor (G-CSF) preserves β-cell function for at least 12 months in type 1 diabetes. Herein, we describe metabolic and immunological parameters 24 months following treatment. Patients with established type 1 diabetes (duration 4-24 months) were randomized to ATG and pegylated G-CSF (ATG+G-CSF) (N = 17) or placebo (N = 8). Primary outcomes included C-peptide area under the curve (AUC) following a mixed-meal tolerance test (MMTT) and flow cytometry. "Responders" (12-month C-peptide ≥ baseline), "super responders" (24-month C-peptide ≥ baseline), and "nonresponders" (12-month C-peptide < baseline) were evaluated for biomarkers of outcome. At 24 months, MMTT-stimulated AUC C-peptide was not significantly different in ATG+G-CSF (0.49 nmol/L/min) versus placebo (0.29 nmol/L/min). Subjects treated with ATG+G-CSF demonstrated reduced CD4⁺ T cells and CD4⁺/CD8⁺ T-cell ratio and increased CD16⁺CD56^hi natural killer cells (NK), CD4⁺ effector memory T cells (Tem), CD4⁺PD-1⁺ central memory T cells (Tcm), Tcm PD-1 expression, and neutrophils. FOXP3⁺Helios⁺ regulatory T cells (Treg) were elevated in ATG+G-CSF subjects at 6, 12, and 18 but not 24 months. Immunophenotyping identified differential HLA-DR expression on monocytes and NK and altered CXCR3 and PD-1 expression on T-cell subsets. As such, a group of metabolic and immunological responders was identified. A phase II study of ATG+G-CSF in patients with new-onset type 1 diabetes is ongoing and may support ATG+G-CSF as a prevention strategy in high-risk subjects.

A Well Woman's Health Maintenance Study Comparing Physical Fitness and Group Support Programs

This pilot study examined the effect of group support and physical activity on 75 physiological and psychological indicators of health in well women 40 to 64 years old Fifty subjects were randomly placed in one of four groups: physical fitness (exercise), group support (discussion), physical fitness and group support, or control Groups met weekly for 3 months in structured programs. All subjects completed daily diaries Pre- and post-program psychosocial measures were obtained by questionnaires and standardized tests. Physical measurements were determined through treadmill pulmonary function, body composition, flexibility, and strength tests. A two-way analysis of variance determined differences between groups for changes in all measurements Diastolic pressure, quadriceps strength, and participation in organized sports decreased more in the exercise than nonexercise groups Maximal oxygen consumption, time on the treadmill, time to get 90% of maximal oxygen consumption, and amount of exercise done increased more in the exercise group. Heart rate increased more in the discussion than non-discussion group, while hand strength and forced vital capacity decreased more in the discussion group. Subjects who exercised felt they weren't doing enough exercise while those in discussion groups felt the opposite. Those exercising decreased their stimulant intake, and those not exercising increased their intake The purpose of this study was to delineate specific measurable variables and to identify procedural changes for a larger study.

Outcomes after inappropriate nuclear myocardial perfusion imaging: A meta-analysis

BACKGROUND

The relationship between inappropriate MPI and cardiovascular outcomes is poorly understood. We sought to systematically review the literature on appropriate use criteria (AUC) for MPI, including temporal trend of inappropriate testing and resulting cardiovascular outcomes.

METHODS

We searched the MEDLINE database for studies related to AUC and MPI. The co-primary outcomes were abnormal test results and the presence of cardiac ischemia. Random effects odds ratios (OR) were constructed using DerSimonian-Laird method.

RESULTS

A total of 22 studies with 23,443 patients were included. The prevalence of inappropriate testing was 14.8% [95% confidence interval (CI) 11.6%-18.7%]. Inappropriate MPI studies were less likely to be abnormal (OR 0.41 95% CI 0.35-0.49, P < .0001) and to demonstrate ischemia (OR 0.40, 95% CI 0.24-0.67, P < .0001) compared to appropriate testing. No difference in the rate of inappropriate tests was detected based on the midpoint of the enrollment year (P = .54). The pattern of ordering inappropriate studies was not different between cardiology and non-cardiology providers (OR 0.74, 95% CI 0.51-1.06, P = .10).

CONCLUSION

Inappropriate MPI studies are less likely to yield abnormal results or demonstrate myocardial ischemia. The rate of inappropriate MPI has not decreased over time.

Comparing Glaucomatous Disc Change Using Stereo Disc Viewing and the MatchedFlicker Software Program in Ophthalmologists-in-Training

PURPOSE

To compare the accuracy and speed of using the computerized MatchedFlicker software program (EyeIC Inc, Narberth, Pennsylvania, USA) to evaluate glaucomatous optic disc change against the traditional gold standard of manually examining stereoscopic disc photographs.

DESIGN

A prospective evaluation of diagnostic technology.

METHODS

Two resident ophthalmologists and 1 glaucoma fellow at the University of Florida independently evaluated 140 image pairs from 100 glaucomatous/ocular hypertensive patient eyes using a handheld stereo viewer and the MatchedFlicker program. Fifty had progression to glaucoma as determined by the Ocular Hypertension Treatment Study (OHTS) Optic Disc Reading Group and the OHTS Endpoint Committee in the OHTS, and 50 more had photographs taken a few minutes apart, which were negative controls with no progression. Twenty photograph pairs from each group were duplicated to determine reviewer variability. Photographs were examined in alternating blocks of 70 photograph pairs for each method, with the starting viewing method randomized. Reviewer accuracy and time to review for each method were measured.

RESULTS

Using the handheld stereo viewer, the reviewers correctly identified progression or nonprogression in 76.0% of the slide pairs. Using the MatchedFlicker software, 87.6% were correctly identified (P = .011). Evaluator speed averaged 34.1 seconds per image pair with the stereo viewer vs 24.9 seconds with the MatchedFlicker program (P = .044). Overall, Flicker was significantly more specific but less sensitive than stereo slides. Trainees appeared more reluctant to identify glaucoma progression from slides than from Flicker. For the 2 less experienced trainees Flicker was significantly more accurate.

CONCLUSION

The MatchedFlicker software had a greater accuracy and was quicker to perform than using a handheld stereoscopic viewer.

Infant-Feeding Intentions and Practices of Internal Medicine Physicians

BACKGROUND

Personal breastfeeding behavior of physician mothers is associated with their clinical breastfeeding advocacy, which in turn impacts patients' breastfeeding behavior. Internists can play an important role in breastfeeding advocacy as they usually come in contact with mothers longitudinally.

OBJECTIVE

To explore the personal infant-feeding decisions and behavior of physician mothers in internal medicine (IM).

MATERIALS AND METHODS

Physicians with current or previous IM training were isolated from our "Breastfeeding Among Physicians" database. The data in the database were gathered from cross-sectional surveys of 130 physician volunteers, mainly affiliated with the Johns Hopkins University School of Medicine (Baltimore, MD) and the University of Florida College of Medicine (Gainesville, FL).

RESULTS

Seventy-two mothers reported current or previous IM training and had 196 infants. Breastfeeding rates were 96% at birth, 77% at 6 months, and 40% at 12 months. Exclusive breastfeeding rates were 78% at birth, 67% at 3 months, and 30% at 6 months. While maternal goal for breastfeeding duration correlated with duration of both exclusive and any breastfeeding, there was a consistent and appreciable disparity between maternal duration goal and actual breastfeeding duration. The participants reported work-related reasons for early supplementation and breastfeeding cessation.

CONCLUSIONS

We have described for the first time in the literature the personal infant-feeding intentions and behavior of a cohort of IM physician mothers. Workplace interventions to enable internists to maintain breastfeeding after return to work and to achieve their breastfeeding goals might improve the health of these mothers and their infants and positively impact their clinical breastfeeding advocacy.

Risk of Suicidal Events With Atomoxetine Compared to Stimulant Treatment: A Cohort Study

BACKGROUND

Antidepressant effects on increased suicidality in children have raised public concern in recent years. Approved in 2002 for attention-deficit/hyperactivity disorder treatment, the selective noradrenalin-reuptake-inhibitor atomoxetine was initially investigated for the treatment of depression. In post-hoc analyses of clinical trial data, atomoxetine has been associated with an increased risk of suicidal ideation in children and adolescents. We analyzed whether the observed increased risk of suicidal ideation in clinical trials translates into an increased risk of suicidal events in pediatric patients treated with atomoxetine compared with stimulants in 26 Medicaid programs.

METHODS

Employing a retrospective cohort design, we used propensity score-adjusted Cox proportional hazard models to evaluate the risk of suicide and suicide attempt in pediatric patients initiating treatment with atomoxetine compared with stimulants from 2002 to 2006.

RESULTS

The first-line treatment cohort included 279 315 patients. During the first year of follow-up, the adjusted hazard ratio for current atomoxetine use compared with current stimulant use was 0.95 (95% CI 0.47-1.92, P = .88). The second-line treatment cohort included 220 215 patients. During the first year of follow-up, the adjusted hazard ratio for current atomoxetine use compared with current stimulant use was 0.71 (95% CI 0.30-1.67, P = .43).

CONCLUSIONS

First- and second-line treatment of youths age 5 to 18 with atomoxetine compared with stimulants was not significantly associated with an increased risk of suicidal events. The low incidence of suicide and suicide attempt resulted in wide confidence intervals and did not allow stratified analysis of high-risk groups or assessment of suicidal risk associated with long-term use of atomoxetine.

On variance estimate for covariate adjustment by propensity score analysis

Propensity score (PS) methods have been used extensively to adjust for confounding factors in the statistical analysis of observational data in comparative effectiveness research. There are four major PS-based adjustment approaches: PS matching, PS stratification, covariate adjustment by PS, and PS-based inverse probability weighting. Though covariate adjustment by PS is one of the most frequently used PS-based methods in clinical research, the conventional variance estimation of the treatment effects estimate under covariate adjustment by PS is biased. As Stampf et al. have shown, this bias in variance estimation is likely to lead to invalid statistical inference and could result in erroneous public health conclusions (e.g., food and drug safety and adverse events surveillance). To address this issue, we propose a two-stage analytic procedure to develop a valid variance estimator for the covariate adjustment by PS analysis strategy. We also carry out a simple empirical bootstrap resampling scheme. Both proposed procedures are implemented in an R function for public use. Extensive simulation results demonstrate the bias in the conventional variance estimator and show that both proposed variance estimators offer valid estimates for the true variance, and they are robust to complex confounding structures. The proposed methods are illustrated for a post-surgery pain study. Copyright © 2016 John Wiley & Sons, Ltd.

Low- Versus High-Intensity Plyometric Exercise During Rehabilitation After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Plyometric exercise is used during rehabilitation after anterior cruciate ligament (ACL) reconstruction to facilitate the return to sports participation. However, clinical outcomes have not been examined, and high loads on the lower extremity could be detrimental to knee articular cartilage.

PURPOSE

To compare the immediate effect of low- and high-intensity plyometric exercise during rehabilitation after ACL reconstruction on knee function, articular cartilage metabolism, and other clinically relevant measures.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

Twenty-four patients who underwent unilateral ACL reconstruction (mean, 14.3 weeks after surgery; range, 12.1-17.7 weeks) were assigned to 8 weeks (16 visits) of low- or high-intensity plyometric exercise consisting of running, jumping, and agility activities. Groups were distinguished by the expected magnitude of vertical ground-reaction forces. Testing was conducted before and after the intervention. Primary outcomes were self-reported knee function (International Knee Documentation Committee [IKDC] subjective knee form) and a biomarker of articular cartilage degradation (urine concentrations of crosslinked C-telopeptide fragments of type II collagen [uCTX-II]). Secondary outcomes included additional biomarkers of articular cartilage metabolism (urinary concentrations of the neoepitope of type II collagen cleavage at the C-terminal three-quarter-length fragment [uC2C], serum concentrations of the C-terminal propeptide of newly formed type II collagen [sCPII]) and inflammation (tumor necrosis factor-α), functional performance (maximal vertical jump and single-legged hop), knee impairments (anterior knee laxity, average knee pain intensity, normalized quadriceps strength, quadriceps symmetry index), and psychosocial status (kinesiophobia, knee activity self-efficacy, pain catastrophizing). The change in each measure was compared between groups. Values before and after the intervention were compared with the groups combined.

RESULTS

The groups did not significantly differ in the change of any primary or secondary outcome measure. Of interest, sCPII concentrations tended to change in opposite directions (mean ± SD: low-intensity group, 28.7 ± 185.5 ng/mL; high-intensity group, -200.6 ± 255.0 ng/mL; P = .097; Cohen d = 1.03). Across groups, significant changes after the intervention were increased the IKDC score, vertical jump height, normalized quadriceps strength, quadriceps symmetry index, and knee activity self-efficacy and decreased average knee pain intensity.

CONCLUSION

No significant differences were detected between the low- and high-intensity plyometric exercise groups. Across both groups, plyometric exercise induced positive changes in knee function, knee impairments, and psychosocial status that would support the return to sports participation after ACL reconstruction. The effect of plyometric exercise intensity on articular cartilage requires further evaluation.

REGISTRATION NUMBER

Clinicaltrials.gov NCT01851655.

Novel Application of a Reverse Triage Protocol Providing Increased Access to Care in an Outpatient, Primary Care Clinic Setting

BACKGROUND AND OBJECTIVES

As the number of patients with access to care increases, outpatient clinics will need to implement innovative strategies to maintain or enhance clinic efficiency. One viable alternative involves reverse triage.

METHODS

A reverse triage protocol was implemented during a student-run free clinic. Each patient's chief complaint(s) were obtained at the beginning of the clinic session and ranked by increasing complexity. "Complexity" was defined as the subjective amount of time required to provide a full, thorough evaluation of a patient. Less complex cases were prioritized first since they could be expedited through clinic processing and allow for more time and resources to be dedicated to complex cases. Descriptive statistics were used to characterize and summarize the data obtained. Categorical variables were analyzed using chi-square. A time series analysis of the outcome versus centered time in weeks was also conducted.

RESULTS

The average number of patients seen per clinic session increased by 35% (9.5 versus 12.8) from pre-implementation of the reverse triage protocol to 6 months after the implementation of the protocol.

CONCLUSIONS

The implementation of a reverse triage in an outpatient setting significantly increased clinic efficiency as noted by a significant increase in the number of patients seen during a clinic session.

Low-event-rate meta-analyses of clinical trials: implementing good practices

Meta‐analysis of clinical trials is a methodology to summarize information from a collection of trials about an intervention, in order to make informed inferences about that intervention. Random effects allow the target population outcomes to vary among trials. Since meta‐analysis is often an important element in helping shape public health policy, society depends on biostatisticians to help ensure that the methodology is sound. Yet when meta‐analysis involves randomized binomial trials with low event rates, the overwhelming majority of publications use methods currently not intended for such data. This statistical practice issue must be addressed. Proper methods exist, but they are rarely applied. This tutorial is devoted to estimating a well‐defined overall relative risk, via a patient‐weighted random‐effects method. We show what goes wrong with methods based on ‘inverse‐variance’ weights, which are almost universally used. To illustrate similarities and differences, we contrast our methods, inverse‐variance methods, and the published results (usually inverse‐variance) for 18 meta‐analyses from 13 Journal of the American Medical Association articles. We also consider the 2007 case of rosiglitazone (Avandia), where important public health issues were at stake, involving patient cardiovascular risk. The most widely used method would have reached a different conclusion. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

The influence of type 1 diabetes on pancreatic weight

AIMS/HYPOTHESIS

Previous studies of pancreases obtained at autopsy or by radiography note reduced pancreas weight (PW) and size, respectively, in type 1 diabetes; this finding is widely considered to be the result of chronic insulinopenia. This literature is, however, limited with respect to the influence of age, sex, anthropometric factors and disease duration on these observations. Moreover, data are sparse for young children, a group of particular interest for type 1 diabetes. We hypothesised that the pancreas-to-body weight ratio would normalise confounding inter-subject factors, thereby permitting better characterisation of PW in type 1 diabetes.

METHODS

Transplant-grade pancreases were recovered from 216 organ donors with type 1 diabetes (n = 90), type 2 diabetes (n = 40) and no diabetes (n = 86). Whole-organ and head, body and tail weights were determined. The relative PW (RPW; PW [g] / body weight [kg]) was calculated and tested for normalisation of potential differences due to age, sex and BMI.

RESULTS

PW significantly correlated with body weight in control donors (R (2) = 0.76, p < 0.001) while RPW (1.03 ± 0.36, mean ± SD) did not significantly differ across ages (0-58 years). Donors with type 1 diabetes (0.57 ± 0.18, p < 0.001), but not those with type 2 diabetes (0.93 ± 0.30), had significantly lower RPW. The relative weights of each pancreatic region from donors with type 1 diabetes were significantly smaller than those of regions from control donors and donors with type 2 diabetes (p < 0.001). Perhaps most interestingly, the RPW was not significantly associated with duration of type 1 diabetes or type 2 diabetes.

CONCLUSIONS/INTERPRETATION

RPW allows for comparisons across a wide range of donor ages by eliminating confounding variables. These data validate an interesting feature of the type 1 diabetes pancreas and underscore the need for additional studies to identify the mechanistic basis for this finding, including those beyond the chronic loss of endogenous insulin secretion.

Chloral hydrate, through biotransformation to dichloroacetate, inhibits maleylacetoacetate isomerase and tyrosine catabolism in humans

BACKGROUND

Chloral hydrate (CH), a sedative and metabolite of the environmental contaminant trichloroethylene, is metabolized to trichloroacetic acid, trichloroethanol, and possibly dichloroacetate (DCA). DCA is further metabolized by glutathione transferase zeta 1 (GSTZ1), which is identical to maleylacetoacetate isomerase (MAAI), the penultimate enzyme in tyrosine catabolism. DCA inhibits its own metabolism through depletion/inactivation of GSTZ1/MAAI with repeated exposure, resulting in lower plasma clearance of the drug and the accumulation of the urinary biomarker maleylacetone (MA), a metabolite of tyrosine. It is unknown if GSTZ1/MAAI may participate in the metabolism of CH or any of its metabolites and, therefore, affect tyrosine catabolism. Stable isotopes were utilized to determine the biotransformation of CH, the kinetics of its major metabolites, and the influence, if any, of GSTZ1/MAAI.

METHODS

Eight healthy volunteers (ages 21-40 years) received a dose of 1 g of CH (clinical dose) or 1.5 μg/kg (environmental) for five consecutive days. Plasma and urinary samples were analyzed by gas chromatography-mass spectrometry.

RESULTS

Plasma DCA (1.2-2.4 μg/mL), metabolized from CH, was measured on the fifth day of the 1 g/day CH dosage but was undetectable in plasma at environmentally relevant doses. Pharmacokinetic measurements from CH metabolites did not differ between slow and fast GSTZ1 haplotypes. Urinary MA levels increased from undetectable to 0.2-0.7 μg/g creatinine with repeated CH clinical dose exposure. Kinetic modeling of a clinical dose of 25 mg/kg DCA administered after 5 days of 1 g/day CH closely resembled DCA kinetics obtained in previously naïve individuals.

CONCLUSIONS

These data indicate that the amount of DCA produced from clinically relevant doses of CH, although insufficient to alter DCA kinetics, is sufficient to inhibit MAAI and tyrosine catabolism, as evidenced by the accumulation of urinary MA.

A randomized, placebo-controlled trial of late Na current inhibition (ranolazine) in coronary microvascular dysfunction (CMD): impact on angina and myocardial perfusion reserve

Aims

The mechanistic basis of the symptoms and signs of myocardial ischaemia in patients without obstructive coronary artery disease (CAD) and evidence of coronary microvascular dysfunction (CMD) is unclear. The aim of this study was to mechanistically test short-term late sodium current inhibition (ranolazine) in such subjects on angina, myocardial perfusion reserve index, and diastolic filling.

Materials and results

Randomized, double-blind, placebo-controlled, crossover, mechanistic trial in subjects with evidence of CMD [invasive coronary reactivity testing or non-invasive cardiac magnetic resonance imaging myocardial perfusion reserve index (MPRI)]. Short-term oral ranolazine 500–1000 mg twice daily for 2 weeks vs. placebo. Angina measured by Seattle Angina Questionnaire (SAQ) and SAQ-7 (co-primaries), diary angina (secondary), stress MPRI, diastolic filling, quality of life (QoL). Of 128 (96% women) subjects, no treatment differences in the outcomes were observed. Peak heart rate was lower during pharmacological stress during ranolazine (−3.55 b.p.m., P < 0.001). The change in SAQ-7 directly correlated with the change in MPRI (correlation 0.25, P = 0.005). The change in MPRI predicted the change in SAQ QoL, adjusted for body mass index (BMI), prior myocardial infarction, and site (P = 0.0032). Low coronary flow reserve (CFR <2.5) subjects improved MPRI (P < 0.0137), SAQ angina frequency (P = 0.027), and SAQ-7 (P = 0.041).

Conclusions

In this mechanistic trial among symptomatic subjects, no obstructive CAD, short-term late sodium current inhibition was not generally effective for SAQ angina. Angina and myocardial perfusion reserve changes were related, supporting the notion that strategies to improve ischaemia should be tested in these subjects.

Trial registration

clinicaltrials.gov Identifier: NCT01342029.

Treatment of isolated mediastinal and hilar recurrence of lung cancer with bronchoscopic endobronchial ultrasound guided intratumoral injection of chemotherapy with cisplatin

PURPOSE

A common pattern of recurrence in lung cancer after receiving full dose external beam radiation therapy (EBRT) to targeted sites is isolated mediastinal and hilar recurrence (IMHR). Treatment options for these patients are limited to palliative radiation, chemotherapy, and/or best supportive care. We describe our experience with treating IMHR with bronchoscopic endobronchial ultrasound (EBUS) guided intratumoral injection of cisplatin (ITC).

METHODS

Patients treated between Jan 2009-September 2014 with ITC for IMHR were included. Patient demographics, tumor histology, size, concurrent therapy, location, number of sites treated, treatment sessions, and encounters were abstracted. Responses were analyzed on follow-up scans 8-12 weeks after the last treatment session using RECIST 1.1 criteria. Locoregional recurrence, progression-free survival (PFS), and overall survival were measured.

RESULTS

50 sites were treated in 36 patients (19 males, 17 females) with mean age 61.9±8.5 years. Eight sites treated on subsequent encounters were excluded and one patient had an unevaluable response, leaving 35 patients and 41 sites for final analysis. 24/35 (69%) had complete or partial response (responders), whereas 11/35 (31%) had stable or progressive disease (non-responders). There were no significant differences in response based on histology, size, and concurrent therapy. Median survival for the group was 8 months (95% CI of 6-11 mo). Responders had significantly higher survival and PFS than non-responders. Two patients treated with concurrent EBRT, developed broncho-mediastinal fistula.

CONCLUSION

EBUS guided intratumoral cisplatin for IMHR appears to be safe and effective, and may represent a new treatment paradigm for this patient population.

Repetitive Transcranial Magnetic Stimulation (rTMS) Therapy in Parkinson Disease: A Meta-Analysis

OBJECTIVE

Several studies have reported repetitive transcranial magnetic stimulation (rTMS) therapy as an effective treatment for the control of motor symptoms in Parkinson disease. The objective of the study is to quantify the overall efficacy of this treatment.

TYPES

Systematic review and meta-analysis.

LITERATURE SURVEY

We reviewed the literature on clinical rTMS trials in Parkinson disease since the technique was introduced in 1980. We used the following databases: MEDLINE, Web of Science, Cochrane, and CINAHL.

METHODOLOGY

PATIENTS AND SETTING

Patients with Parkinson disease who were participating in prospective clinical trials that included an active arm and a control arm and change in motor scores on Unified Parkinson's Disease Rating Scale as the primary outcome. We pooled data from 21 studies that met these criteria. We then analyzed separately the effects of low- and high-frequency rTMS on clinical motor improvements.

SYNTHESIS

The overall pooled mean difference between treatment and control groups in the Unified Parkinson's Disease Rating Scale motor score was significant (4.0 points, 95% confidence interval, 1.5, 6.7; P = .005). rTMS therapy was effective when low-frequency stimulation (≤ 1 Hz) was used with a pooled mean difference of 3.3 points (95% confidence interval 1.6, 5.0; P = .005). There was a trend for significance when high-frequency stimulation (≥ 5 Hz) studies were evaluated with a pooled mean difference of 3.9 points (95% confidence interval, -0.7, 8.5; P = .08). rTMS therapy demonstrated benefits at short-term follow-up (immediately after a treatment protocol) with a pooled mean difference of 3.4 points (95% confidence interval, 0.3, 6.6; P = .03) as well as at long-term follow-up (average follow-up 6 weeks) with mean difference of 4.1 points (95% confidence interval, -0.15, 8.4; P = .05). There were insufficient data to statistically analyze the effects of rTMS when we specifically examined bradykinesia, gait, and levodopa-induced dyskinesia using quantitative methods.

CONCLUSION

rTMS therapy in patients with Parkinson disease results in mild-to-moderate motor improvements and has the potential to be used as an adjunct therapy for the treatment of Parkinson disease. Future large, sample studies should be designed to isolate the specific clinical features of Parkinson disease that respond well to rTMS therapy.

Meta-analysis of safety for low event-rate binomial trials

This article focuses on meta-analysis of low event-rate binomial trials. We introduce two forms of random effects: (1) 'studies at random' (SR), where we assume no more than independence between studies; and (2) 'effects at random' (ER), which forces the effect size distribution to be independent of the study design. On the basis of the summary estimates of proportions, we present both unweighted and study-size weighted methods, which, under SR, target different population parameters. We demonstrate mechanistically that the popular DerSimonian-Laird (DL) method, as DL actually warned in their paper, should never be used in this setting. We conducted a survey of the major cardiovascular literature on low event-rate studies and found that DL using odds ratios or relative risks to be the clear method of choice. We looked at two high profile examples from diabetes and cancer, respectively, where the choice of weighted versus unweighted methods makes a large difference. A large simulation study supports the accuracy of the coverage of our approximate confidence intervals. We recommend that before looking at their data, users should prespecify which target parameter they intend to estimate (weighted vs. unweighted) but estimate the other as a secondary analysis. Copyright © 2012 John Wiley & Sons, Ltd.

The effect of the addition of allopurinol on blood pressure control in African Americans treated with a thiazide-like diuretic

We tested the hypothesis that xanthine oxidase inhibition among African Americans receiving the thiazide-type diuretic chlorthalidone may improve blood pressure control with fewer hyperuricemia-related side effects. We performed a randomized, double-blind, placebo-controlled study of African Americans with Stage 1 hypertension without clinically significant renal disease. One hundred fifty African American men or women between the ages of 18 and 65 years who met the exclusion/inclusion criteria with untreated or treated hypertension were started on chlorthalidone (25 mg/d) and potassium chloride. After a 5-week run-in on chlorthalidone, baseline testing was performed and they were randomized to allopurinol (300 mg/dL) or placebo with doses adjusted based on uric acid levels and followed for 8 weeks. One hundred ten subjects completed the study. Baseline systolic blood pressures after the 5-week chlorthalidone run-in were 119.9 ± 13.6 in the allopurinol group and 117 ± 11.2 in the placebo group indicating excellent blood pressure control with the single agent. After at least 4 week postrandomization, the difference in mean change in systolic blood pressure in allopurinol less placebo from visits 5 to 3 was 4.3 mm Hg (95% confidence interval, -0.2 to 8.7; P = .059). The difference in mean change in uric acid levels over the same period was 2.1 mg/dL (95% confidence interval, 1.7-2.6; P < .001). The use of chlorthalidone with or without allopurinol resulted in excellent blood pressure control. The addition of allopurinol tended to improve clinic blood pressure, but the difference from the group receiving chlorthalidone alone was not statistically significant.

Design strategy for a smoking cessation trial of survival

Despite unequivocal evidence that smoking cessation is beneficial in terms of survival, there is at present no firm evidence that smoking cessation programs save lives. While they do increase quit rates, the collective evidence from randomized trials is inconclusive with respect to long-term survival. Withdrawal symptoms and the potential for harm when a subjects relapses after a prolonged period of cessation (e.g., 5+ years) might mitigate some or all of the benefits of the sustained quitters. This paper will review the key survival epidemiology and argue for a large randomized field trial of about 30,000 subjects, followed personally for 5 years and collectively for 15 years through the National Death Index. The intervention should be personalized, but reproducible through a treatment assignment algorithm. Personal coaching should be a major part of the intervention. Important short-term data on healthcare utilization should also be collected. Strong financial motivation for quitting (or prevention of smoking in the first place) is also presented. This paper is intended to motivate a large collective effort amongst the US Clinical and Translational Science Awardees to design the intervention and bring together the interested players to conduct the study.

On model selections for repeated measurement data in clinical studies

Repeated measurement designs have been widely used in various randomized controlled trials for evaluating long-term intervention efficacies. For some clinical trials, the primary research question is how to compare two treatments at a fixed time, using a t-test. Although simple, robust, and convenient, this type of analysis fails to utilize a large amount of collected information. Alternatively, the mixed-effects model is commonly used for repeated measurement data. It models all available data jointly and allows explicit assessment of the overall treatment effects across the entire time spectrum. In this paper, we propose an analytic strategy for longitudinal clinical trial data where the mixed-effects model is coupled with a model selection scheme. The proposed test statistics not only make full use of all available data but also utilize the information from the optimal model deemed for the data. The performance of the proposed method under various setups, including different data missing mechanisms, is evaluated via extensive Monte Carlo simulations. Our numerical results demonstrate that the proposed analytic procedure is more powerful than the t-test when the primary interest is to test for the treatment effect at the last time point. Simulations also reveal that the proposed method outperforms the usual mixed-effects model for testing the overall treatment effects across time. In addition, the proposed framework is more robust and flexible in dealing with missing data compared with several competing methods. The utility of the proposed method is demonstrated by analyzing a clinical trial on the cognitive effect of testosterone in geriatric men with low baseline testosterone levels.

Anti-thymocyte globulin/G-CSF treatment preserves β cell function in patients with established type 1 diabetes

BACKGROUND

Previous efforts to preserve β cell function in individuals with type 1 diabetes (T1D) have focused largely on the use of single immunomodulatory agents administered within 100 days of diagnosis. Based on human and preclinical studies, we hypothesized that a combination of low-dose anti-thymocyte globulin (ATG) and pegylated granulocyte CSF (G-CSF) would preserve β cell function in patients with established T1D (duration of T1D >4 months and <2 years).

METHODS

A randomized, single-blinded, placebo-controlled trial was performed on 25 subjects: 17 subjects received ATG (2.5 mg/kg intravenously) followed by pegylated G-CSF (6 mg subcutaneously every 2 weeks for 6 doses) and 8 subjects received placebo. The primary outcome was the 1-year change in AUC C-peptide following a 2-hour mixed-meal tolerance test (MMTT). At baseline, the age (mean ± SD) was 24.6 ± 10 years; mean BMI was 25.4 ± 5.2 kg/m²; mean A1c was 6.5% ± 1.1%; insulin use was 0.31 ± 0.22 units/kg/d; and length of diagnosis was 1 ± 0.5 years.

RESULTS

Combination ATG/G-CSF treatment tended to preserve β cell function in patients with established T1D. The mean difference in MMTT-stimulated AUC C-peptide between treated and placebo subjects was 0.28 nmol/l/min (95% CI 0.001-0.552, P = 0.050). A1c was lower in ATG/G-CSF-treated subjects at the 6-month study visit. ATG/G-CSF therapy was associated with relative preservation of Tregs.

CONCLUSIONS

Patients with established T1D may benefit from combination immunotherapy approaches to preserve β cell function. Further studies are needed to determine whether such approaches may prevent or delay the onset of the disease.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01106157.

FUNDING

The Leona M. and Harry B. Helmsley Charitable Trust and Sanofi.

Cardiovascular risks and elevation of serum DHT vary by route of testosterone administration: a systematic review and meta-analysis

BACKGROUND

Potential cardiovascular (CV) risks of testosterone replacement therapy (TRT) are currently a topic of intense interest. However, no studies have addressed CV risk as a function of the route of administration of TRT.

METHODS

Two meta-analyses were conducted, one of CV adverse events (AEs) in 35 randomized controlled trials (RCTs) of TRT lasting 12 weeks or more, and one of 32 studies reporting the effect of TRT on serum testosterone and dihydrotestosterone (DHT).

RESULTS

CV risks of TRT: Of 2,313 studies identified, 35 were eligible and included 3,703 mostly older men who experienced 218 CV-related AEs. No significant risk for CV AEs was present when all TRT administration routes were grouped (relative risk (RR) = 1.28, 95% confidence interval (CI): 0.76 to 2.13, P = 0.34). When analyzed separately, oral TRT produced significant CV risk (RR = 2.20, 95% CI: 1.45 to 3.55, P = 0.015), while neither intramuscular (RR = 0.66, 95% CI: 0.28 to 1.56, P = 0.32) nor transdermal (gel or patch) TRT (RR = 1.27, 95% CI: 0.62 to 2.62, P = 0.48) significantly altered CV risk. Serum testosterone/DHT following TRT: Of 419 studies identified, 32 were eligible which included 1,152 men receiving TRT. No significant difference in the elevation of serum testosterone was present between intramuscular or transdermal TRT. However, transdermal TRT elevated serum DHT (5.46-fold, 95% CI: 4.51 to 6.60) to a greater magnitude than intramuscular TRT (2.20-fold, 95% CI: 1.74 to 2.77).

CONCLUSIONS

Oral TRT produces significant CV risk. While no significant effects on CV risk were observed with either injected or transdermal TRT, the point estimates suggest that further research is needed to establish whether administration by these routes is protective or detrimental, respectively. Differences in the degree to which serum DHT is elevated may underlie the varying CV risk by TRT administration route, as elevated serum dihydrotestosterone has been shown to be associated with CV risk in observational studies.

Packed red blood cell transfusion is not associated with increased risk of necrotizing enterocolitis in premature infants

OBJECTIVE

Recent reports have posited a temporal association between blood transfusion with packed red blood cells (BT) and necrotizing enterocolitis (NEC). We evaluated the relationship between BT and NEC among infants at three hospitals who were consented at birth into a prospective observational study of NEC.

STUDY DESIGN

We used a case-control design to match each case of NEC in our study population of infants born at<33 weeks postmenstrual age (PMA) to one control infant using hospital of birth, PMA, birth weight and date of birth.

RESULT

The number of transfusions per infant did not differ between 42 NEC cases and their controls (4.0 ± 4.6 vs 5.4 ± 4.1, mean ± s.d., P = 0.063). A matched-pair analysis did not identify an association of transfusion with NEC in either the 48-h or 7-day time periods before the onset of NEC. Stratifying on matched-sets, the Cox proportional hazard model did not identify any difference in the total number of BTs between the two groups (hazard ratio 0.78, 95% confidence interval 0.57 to 1.07, P = 0.11).

CONCLUSION

In contrast to previous studies, our case-control study did not identify a significant temporal association between BT and NEC. Additional large prospective randomized studies are needed to clarify the relationship between BT and NEC.

Hyperghrelinemia in Prader-Willi syndrome begins in early infancy long before the onset of hyperphagia

Circulating total ghrelin levels are elevated in older children and adults with Prader-Willi syndrome (PWS). However, the presence or absence of hyperghrelinemia in young children with PWS remains controversial. We hypothesized that a more robust way to analyze appetite-regulating hormones in PWS would be by nutritional phases rather than age alone. Our objectives were to compare total serum ghrelin levels in children with PWS by nutritional phase as well as to compare total ghrelin levels in PWS (5 weeks to 21 years of age) to normal weight controls and individuals with early-onset morbid obesity (EMO) without PWS. Fasting serum total ghrelin levels were measured in 60 subjects with PWS, 39 subjects with EMO of unknown etiology, and in 95 normal non-obese sibling controls of PWS or EMO subjects (SibC) in this 12 year longitudinal study. Within PWS, total ghrelin levels were significantly (P < 0.001) higher in earlier nutritional phases: phase 1a (7,906  ±  5,887); 1b (5,057 ± 2,624); 2a (2,905 ± 1,521); 2b (2,615 ± 1,370) and 3 (2,423 ± 1,350). Young infants with PWS also had significantly (P = 0.009) higher total ghrelin levels than did the sibling controls. Nutritional phase is an important independent prognostic factor of total ghrelin levels in individuals with PWS. Circulating ghrelin levels are elevated in young children with PWS long before the onset of hyperphagia, especially during the early phase of poor appetite and feeding. Therefore, it seems unlikely that high ghrelin levels are directly responsible for the switch to the hyperphagic nutritional phases in PWS.

Improving residents' clinical approach to obesity: impact of a multidisciplinary didactic curriculum

BACKGROUND/OBJECTIVES

Obesity has been declared a 21st century pandemic by WHO. Yet surveys reveal physicians-in-training are uncomfortable managing obesity. One major barrier is the lack of residency education on obesity management. This study incorporates an obesity-specific didactic curriculum into an internal medicine (IM) residency programme and assesses its impact on residents' knowledge, attitudes, practice behaviours, and clinical outcomes in patients with obesity.

METHODS

The intervention consisted of four, 1 h, obesity-specific lectures in the University of Florida Resident Noon Conference. Lectures were taught by multidisciplinary experts and offered to 75 IM residents every 2 weeks from 5 November 2010 to 17 December 2010. Impact on IM residents' knowledge and attitudes was assessed by a pre- and post-intervention Obesity Awareness Questionnaire (OAQ). IM residents' clinical performance was assessed by chart reviews of 238 patients with body mass index >25 kg/m(2) in residents' clinics 4 months pre- and 6 months post-intervention for three clinical outcomes and seven practice behaviours on obesity management. Pre- and post-intervention outcomes were compared via paired t tests (quantitative data) or McNemar's test (binary data).

RESULTS

Mean lecture attendance was 25/75 residents (33%) per lecture. Survey response was 67/75 residents (89%) pre-OAQ and 63/75 residents (84%) post-OAQ. While most attitudes remained unchanged, IM residents gained significant confidence in exercise counselling, safety of bariatric surgery, and patients' weight loss potential; they were more likely to address obesity in the plan and referrals to bariatric surgery. Clinical outcomes and IM residents' knowledge demonstrated no improvement.

CONCLUSIONS

Our brief lecture-based curriculum has the potential to improve IM residents' attitudes and practice behaviours towards obesity. The lack of improvement in clinical outcomes and resident knowledge prompts the need for multimodal, longitudinal curricula with experiential application of obesity medicine.

Testosterone alters iron metabolism and stimulates red blood cell production independently of dihydrotestosterone

Testosterone (T) stimulates erythropoiesis and regulates iron homeostasis. However, it remains unknown whether the (type II) 5α-reduction of T to dihydrotestosterone (DHT) mediates these androgenic effects, as it does in some other tissues. Our purpose was to determine whether inhibition of type II 5α-reductase (via finasteride) alters red blood cell (RBC) production and serum markers of iron homeostasis subsequent to testosterone-enanthate (TE) administration in older hypogonadal men. Sixty men aged ≥60 yr with serum T <300 ng/dl or bioavailable T <70 ng/dl received treatment with TE (125 mg/wk) vs. vehicle paired with finasteride (5 mg/day) vs. placebo using a 2 × 2 factorial design. Over the course of 12 mo, TE increased RBC count 9%, hematocrit 4%, and hemoglobin 8% while suppressing serum hepcidin 57% (P < 0.001 for all measurements). Most of the aforementioned changes occurred in the first 3 mo of treatment, and finasteride coadministration did not significantly alter any of these effects. TE also reduced serum ferritin 32% (P = 0.002) within 3 mo of treatment initiation without altering iron, transferrin, or transferrin saturation. We conclude that TE stimulates erythropoiesis and alters iron homeostasis independently of the type II 5α-reductase enzyme. These results demonstrate that elevated DHT is not required for androgen-mediated erythropoiesis or for alterations in iron homeostasis that would appear to support iron incorporation into RBCs.

Cognitive effects of testosterone and finasteride administration in older hypogonadal men

Serum concentrations of neuroactive androgens decline in older men and, in some studies, low testosterone is associated with decreased cognitive function and incidence of depression. Existing studies evaluating the effect of testosterone administration on cognition in older men have been largely inconclusive, with some studies reporting minor to moderate cognitive benefit, while others indicate no cognitive effect. Our objective was to assess the cognitive effects of treating older hypogonadal men for 1 year with a supraphysiological dose of testosterone, either alone or in combination with finasteride (a type II 5α-reductase inhibitor), in order to determine whether testosterone produces cognitive benefit and whether suppressed dihydrotestosterone influences cognition. Sixty men aged ≥60 years with a serum testosterone concentration of ≤300 ng/dL or bioavailable testosterone ≤70 ng/dL and no evidence of cognitive impairment received testosterone-enanthate (125 mg/week) versus vehicle, paired with finasteride (5 mg/day) versus placebo using a 2×2 factorial design. Testosterone caused a small decrease in depressive symptoms as assessed by the Geriatric Depression Scale and a moderate increase in visuospatial memory as assessed by performance on a recall trial of the Rey-Osterrieth Complex Figure Test. Finasteride caused a small increase in performance on the Benton Judgment of Line Orientation test. In total, major improvements in cognition were not observed either with testosterone or finasteride. Further studies are warranted to determine if testosterone replacement may improve cognition in other domains.

Musculoskeletal and prostate effects of combined testosterone and finasteride administration in older hypogonadal men: a randomized, controlled trial

Testosterone acts directly at androgen receptors and also exerts potent actions following 5α-reduction to dihydrotestosterone (DHT). Finasteride (type II 5α-reductase inhibitor) lowers DHT and is used to treat benign prostatic hyperplasia. However, it is unknown whether elevated DHT mediates either beneficial musculoskeletal effects or prostate enlargement resulting from higher-than-replacement doses of testosterone. Our purpose was to determine whether administration of testosterone plus finasteride to older hypogonadal men could produce musculoskeletal benefits without prostate enlargement. Sixty men aged ≥60 yr with a serum testosterone concentration of ≤300 ng/dl or bioavailable testosterone ≤70 ng/dl received 52 wk of treatment with testosterone enanthate (TE; 125 mg/wk) vs. vehicle, paired with finasteride (5 mg/day) vs. placebo using a 2 × 2 factorial design. Over the course of 12 mo, TE increased upper and lower body muscle strength by 8-14% (P = 0.015 to <0.001), fat-free mass 4.04 kg (P = 0.032), lumbar spine bone mineral density (BMD) 4.19% (P < 0.001), and total hip BMD 1.96% (P = 0.024) while reducing total body fat -3.87 kg (P < 0.001) and trunk fat -1.88 kg (P = 0.0051). In the first 3 mo, testosterone increased hematocrit 4.13% (P < 0.001). Coadministration of finasteride did not alter any of these effects. Over 12 mo, testosterone also increased prostate volume 11.4 cm(3) (P = 0.0051), an effect that was completely prevented by finasteride (P = 0.0027). We conclude that a higher-than-replacement TE combined with finasteride significantly increases muscle strength and BMD and reduces body fat without causing prostate enlargement. These results demonstrate that elevated DHT mediates testosterone-induced prostate enlargement but is not required for benefits in musculoskeletal or adipose tissue.

Sample size verification for clinical trials

In this paper, we shall provide simple methods where nonstatisticians can evaluate sample size calculations for most large simple trials, as an important part of the peer review process, whether a grant, an Institutional Review Board review, an internal scientific review committee, or a journal referee. Through the methods of the paper, not only can readers determine if there is a major disparity, but they can readily determine the correct sample size. It will be of comfort to find in most cases that the sample size computation is correct, but the implications can be major for the minority where serious errors occur. We shall provide three real examples, one where the sample size need was seriously overestimated, one (HIP PRO-test of a device to prevent hip fractures) where the sample size need was dramatically underestimated, and one where the sample size was correct. The HIP PRO case is especially troubling as it went through an NIH study section and two peer reviewed journal reports without anyone catching this sample size error of a factor of more than five-fold.

A Pocock approach to sequential meta-analysis of clinical trials

Three recent papers have provided sequential methods for meta-analysis of two-treatment randomized clinical trials. This paper provides an alternate approach that has three desirable features. First, when carried out prospectively (i.e., we only have the results up to the time of our current analysis), we do not require knowledge of the information fraction (the fraction of the total information that is available at each analysis). Second, the methods work even if the expected values of the effect sizes vary from study to study. Finally, our methods have easily interpretable metrics that make sense under changing effect sizes. Although the other published methods can be adapted to be “group sequential” (recommended), meaning that a set number and timing of looks are specified, rather than looking after every trial, ours can be used in both a continuous or group sequential manner. We provide an example on the role of probiotics in preventing necrotizing enterocolitis in preterm infants.

Randomized clinical trial of implant-supported ceramic-ceramic and metal-ceramic fixed dental prostheses: preliminary results

PURPOSE

The aim of this study was to determine the survival rates over time of implant-supported ceramic-ceramic and metal-ceramic prostheses as a function of core-veneer thickness ratio, gingival connector embrasure design, and connector height.

MATERIALS AND METHODS

An IRB-approved, randomized, controlled clinical trial was conducted as a single-blind pilot study involving 55 patients missing three teeth in either one or two posterior areas. These patients (34 women; 21 men; age range 52-75 years) were recruited for the study to receive a three-unit implant-supported fixed dental prosthesis (FDP). Two implants were placed for each of the 72 FDPs in the study. The implants (Osseospeed, Astra Tech), which were made of titanium, were grit blasted. A gold-shaded, custom-milled titanium abutment (Atlantis, Astra Tech), was secured to each implant body. Each of the 72 FDPs in 55 patients were randomly assigned based on one of the following options: (1) A.

MATERIAL

ceramic-ceramic (Yttria-stabilized zirconia core, pressable fluorapatite glass-ceramic, IPS e.max ZirCAD, and ZirPress, Ivoclar Vivadent) B. metal-ceramic (palladium-based noble alloy, Capricorn, Ivoclar Vivadent, with press-on leucite-reinforced glass-ceramic veneer, IPS InLine POM, Ivoclar Vivadent); (2) occlusal veneer thickness (0.5, 1.0, and 1.5 mm); (3) curvature of gingival embrasure (0.25, 0.5, and 0.75 mm diameter); and (4) connector height (3, 4, and 5 mm). FDPs were fabricated and cemented with dual-cure resin cement (RelyX, Universal Cement, 3M ESPE). Patients were recalled at 6 months, 1 year, and 2 years. FDPs were examined for cracks, fracture, and general surface quality.

RESULTS

Recall exams of 72 prostheses revealed 10 chipping fractures. No fractures occurred within the connector or embrasure areas. Two-sided Fisher's exact tests showed no significant correlation between fractures and type of material system (p = 0.51), veneer thickness (p = 0.75), radius of curvature of gingival embrasure (p = 0.68), and connector height (p = 0.91).

CONCLUSIONS

Although there were no significant associations between connector height, curvature of gingival embrasure, core/veneer thickness ratio, and material system and the survival probability of implant-supported FDPs with zirconia as a core material, the small number of fractures precludes a definitive conclusion on the dominant controlling factor.