Personalized neoantigen vaccine and pembrolizumab in advanced hepatocellular carcinoma: a phase 1/2 trial

Programmed cell death protein 1 (PD-1) inhibitors have modest efficacy as a monotherapy in hepatocellular carcinoma (HCC). A personalized therapeutic cancer vaccine (PTCV) may enhance responses to PD-1 inhibitors through the induction of tumor-specific immunity. We present results from a single-arm, open-label, phase 1/2 study of a DNA plasmid PTCV (GNOS-PV02) encoding up to 40 neoantigens coadministered with plasmid-encoded interleukin-12 plus pembrolizumab in patients with advanced HCC previously treated with a multityrosine kinase inhibitor. Safety and immunogenicity were assessed as primary endpoints, and treatment efficacy and feasibility were evaluated as secondary endpoints. The most common treatment-related adverse events were injection-site reactions, observed in 15 of 36 (41.6%) patients. No dose-limiting toxicities or treatment-related grade ≥3 events were observed. The objective response rate (modified intention-to-treat) per Response Evaluation Criteria in Solid Tumors 1.1 was 30.6% (11 of 36 patients), with 8.3% (3 of 36) of patients achieving a complete response. Clinical responses were associated with the number of neoantigens encoded in the vaccine. Neoantigen-specific T cell responses were confirmed in 19 of 22 (86.4%) evaluable patients by enzyme-linked immunosorbent spot assays. Multiparametric cellular profiling revealed active, proliferative and cytolytic vaccine-specific CD4+ and CD8+ effector T cells. T cell receptor β-chain (TCRβ) bulk sequencing results demonstrated vaccination-enriched T cell clone expansion and tumor infiltration. Single-cell analysis revealed posttreatment T cell clonal expansion of cytotoxic T cell phenotypes. TCR complementarity-determining region cloning of expanded T cell clones in the tumors following vaccination confirmed reactivity against vaccine-encoded neoantigens. Our results support the PTCV's mechanism of action based on the induction of antitumor T cells and show that a PTCV plus pembrolizumab has clinical activity in advanced HCC. ClinicalTrials.gov identifier: NCT04251117 .

Training the Next Generation of Data Monitoring Committee Members: An Initiative of the Heart Failure Collaboratory

Clinical trials are vital for assessing therapeutic interventions. The associated data monitoring committees (DMCs) safeguard patient interests and enhance trial integrity, thus promoting timely, reliable evaluations of those interventions. We face an urgent need to recruit and train new DMC members. The Heart Failure Collaboratory (HFC), a multidisciplinary public-private consortium of academics, trialists, patients, industry representatives, and government agencies, is working to improve the clinical trial ecosystem. The HFC aims to improve clinical trial efficiency and quality by standardizing concepts, and to help meet the demand for experienced individuals on DMCs by creating a standardized approach to training new members. This paper discusses the HFC's training workshop, and an apprenticeship model for new DMC members. It describes opportunities and challenges DMCs face, along with common myths and best practices learned through previous experiences, with an emphasis on data confidentiality and need for quality independent statistical reporting groups.

A template for the authoring of statistical analysis plans

A number of principal investigators may have limited access to biostatisticians, a lack of biostatistical training, or no requirement to complete a timely statistical analysis plan (SAP). SAPs completed early will identify design or implementation weak points, improve protocols, remove the temptation for p-hacking, and enable proper peer review by stakeholders considering funding the trial. An SAP completed at the same time as the study protocol might be the only comprehensive method for at once optimizing sample size, identifying bias, and applying rigor to study design. This ordered corpus of SAP sections with detailed definitions and a variety of examples represents an omnibus of best practice methods offered by biostatistical practitioners inside and outside of industry. The article presents a protocol template for clinical research design, enabling statisticians, from beginners to advanced.

The ProBio trial: molecular biomarkers for advancing personalized treatment decision in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Multiple therapies exist for patients with metastatic castration-resistant prostate cancer (mCRPC). However, their improvement on progression-free survival (PFS) remains modest, potentially explained by tumor molecular heterogeneity. Several prognostic molecular biomarkers have been identified for mCRPC that may have predictive potential to guide treatment selection and prolong PFS. We designed a platform trial to test this hypothesis.

METHODS

The Prostate-Biomarker (ProBio) study is a multi-center, outcome-adaptive, multi-arm, biomarker-driven platform trial for tailoring treatment decisions for men with mCRPC. Treatment decisions in the experimental arms are based on biomarker signatures defined as mutations in certain genes/pathways suggested in the scientific literature to be important for treatment response in mCRPC. The biomarker signatures are determined by targeted sequencing of circulating tumor and germline DNA using a panel specifically designed for mCRPC.

DISCUSSION

Patients are stratified based on the sequencing results and randomized to either current clinical practice (control), where the treating physician decides treatment, or to molecularly driven treatment selection based on the biomarker profile. Outcome-adaptive randomization is implemented to early identify promising treatments for a biomarker signature. Biomarker signature-treatment combinations graduate from the platform when they demonstrate 85% probability of improving PFS compared to the control arm. Graduated combinations are further evaluated in a seamless confirmatory trial with fixed randomization. The platform design allows for new drugs and biomarkers to be introduced in the study.

CONCLUSIONS

The ProBio design allows promising treatment-biomarker combinations to quickly graduate from the platform and be confirmed for rapid implementation in clinical care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03903835. Date of registration: April 4, 2019. Status: Recruiting.

Efficacy of levetiracetam, fosphenytoin, and valproate for established status epilepticus by age group (ESETT): a double-blind, responsive-adaptive, randomised controlled trial

BACKGROUND

Benzodiazepine-refractory, or established, status epilepticus is thought to be of similar pathophysiology in children and adults, but differences in underlying aetiology and pharmacodynamics might differentially affect response to therapy. In the Established Status Epilepticus Treatment Trial (ESETT) we compared the efficacy and safety of levetiracetam, fosphenytoin, and valproate in established status epilepticus, and here we describe our results after extending enrolment in children to compare outcomes in three age groups.

METHODS

In this multicentre, double-blind, response-adaptive, randomised controlled trial, we recruited patients from 58 hospital emergency departments across the USA. Patients were eligible for inclusion if they were aged 2 years or older, had been treated for a generalised convulsive seizure of longer than 5 min duration with adequate doses of benzodiazepines, and continued to have persistent or recurrent convulsions in the emergency department for at least 5 min and no more than 30 min after the last dose of benzodiazepine. Patients were randomly assigned in a response-adaptive manner, using Bayesian methods and stratified by age group (<18 years, 18-65 years, and >65 years), to levetiracetam, fosphenytoin, or valproate. All patients, investigators, study staff, and pharmacists were masked to treatment allocation. The primary outcome was absence of clinically apparent seizures with improved consciousness and without additional antiseizure medication at 1 h from start of drug infusion. The primary safety outcome was life-threatening hypotension or cardiac arrhythmia. The efficacy and safety outcomes were analysed by intention to treat. This study is registered in ClinicalTrials.gov, NCT01960075.

FINDINGS

Between Nov 3, 2015, and Dec 29, 2018, we enrolled 478 patients and 462 unique patients were included: 225 children (aged <18 years), 186 adults (18-65 years), and 51 older adults (>65 years). 175 (38%) patients were randomly assigned to levetiracetam, 142 (31%) to fosphenyltoin, and 145 (31%) were to valproate. Baseline characteristics were balanced across treatments within age groups. The primary efficacy outcome was met in those treated with levetiracetam for 52% (95% credible interval 41-62) of children, 44% (33-55) of adults, and 37% (19-59) of older adults; with fosphenytoin in 49% (38-61) of children, 46% (34-59) of adults, and 35% (17-59) of older adults; and with valproate in 52% (41-63) of children, 46% (34-58) of adults, and 47% (25-70) of older adults. No differences were detected in efficacy or primary safety outcome by drug within each age group. With the exception of endotracheal intubation in children, secondary safety outcomes did not significantly differ by drug within each age group.

INTERPRETATION

Children, adults, and older adults with established status epilepticus respond similarly to levetiracetam, fosphenytoin, and valproate, with treatment success in approximately half of patients. Any of the three drugs can be considered as a potential first-choice, second-line drug for benzodiazepine-refractory status epilepticus.

FUNDING

National Institute of Neurological Disorders and Stroke, National Institutes of Health.

Oseltamivir plus usual care versus usual care for influenza-like illness in primary care: an open-label, pragmatic, randomised controlled trial

BACKGROUND

Antivirals are infrequently prescribed in European primary care for influenza-like illness, mostly because of perceived ineffectiveness in real world primary care and because individuals who will especially benefit have not been identified in independent trials. We aimed to determine whether adding antiviral treatment to usual primary care for patients with influenza-like illness reduces time to recovery overall and in key subgroups.

METHODS

We did an open-label, pragmatic, adaptive, randomised controlled trial of adding oseltamivir to usual care in patients aged 1 year and older presenting with influenza-like illness in primary care. The primary endpoint was time to recovery, defined as return to usual activities, with fever, headache, and muscle ache minor or absent. The trial was designed and powered to assess oseltamivir benefit overall and in 36 prespecified subgroups defined by age, comorbidity, previous symptom duration, and symptom severity, using a Bayesian piece-wise exponential primary analysis model. The trial is registered with the ISRCTN Registry, number ISRCTN 27908921.

FINDINGS

Between Jan 15, 2016, and April 12, 2018, we recruited 3266 participants in 15 European countries during three seasonal influenza seasons, allocated 1629 to usual care plus oseltamivir and 1637 to usual care, and ascertained the primary outcome in 1533 (94%) and 1526 (93%). 1590 (52%) of 3059 participants had PCR-confirmed influenza infection. Time to recovery was shorter in participants randomly assigned to oseltamivir (hazard ratio 1·29, 95% Bayesian credible interval [BCrI] 1·20-1·39) overall and in 30 of the 36 prespecified subgroups, with estimated hazard ratios ranging from 1·13 to 1·72. The estimated absolute mean benefit from oseltamivir was 1·02 days (95% [BCrI] 0·74-1·31) overall, and in the prespecified subgroups, ranged from 0·70 (95% BCrI 0·30-1·20) in patients younger than 12 years, with less severe symptoms, no comorbidities, and shorter previous illness duration to 3·20 (95% BCrI 1·00-5·50) in patients aged 65 years or older who had more severe illness, comorbidities, and longer previous illness duration. Regarding harms, an increased burden of vomiting or nausea was observed in the oseltamivir group.

INTERPRETATION

Primary care patients with influenza-like illness treated with oseltamivir recovered one day sooner on average than those managed by usual care alone. Older, sicker patients with comorbidities and longer previous symptom duration recovered 2-3 days sooner.

FUNDING

European Commission's Seventh Framework Programme.

Randomized Trial of Three Anticonvulsant Medications for Status Epilepticus

BACKGROUND

The choice of drugs for patients with status epilepticus that is refractory to treatment with benzodiazepines has not been thoroughly studied.

METHODS

In a randomized, blinded, adaptive trial, we compared the efficacy and safety of three intravenous anticonvulsive agents - levetiracetam, fosphenytoin, and valproate - in children and adults with convulsive status epilepticus that was unresponsive to treatment with benzodiazepines. The primary outcome was absence of clinically evident seizures and improvement in the level of consciousness by 60 minutes after the start of drug infusion, without additional anticonvulsant medication. The posterior probabilities that each drug was the most or least effective were calculated. Safety outcomes included life-threatening hypotension or cardiac arrhythmia, endotracheal intubation, seizure recurrence, and death.

RESULTS

A total of 384 patients were enrolled and randomly assigned to receive levetiracetam (145 patients), fosphenytoin (118), or valproate (121). Reenrollment of patients with a second episode of status epilepticus accounted for 16 additional instances of randomization. In accordance with a prespecified stopping rule for futility of finding one drug to be superior or inferior, a planned interim analysis led to the trial being stopped. Of the enrolled patients, 10% were determined to have had psychogenic seizures. The primary outcome of cessation of status epilepticus and improvement in the level of consciousness at 60 minutes occurred in 68 patients assigned to levetiracetam (47%; 95% credible interval, 39 to 55), 53 patients assigned to fosphenytoin (45%; 95% credible interval, 36 to 54), and 56 patients assigned to valproate (46%; 95% credible interval, 38 to 55). The posterior probability that each drug was the most effective was 0.41, 0.24, and 0.35, respectively. Numerically more episodes of hypotension and intubation occurred in the fosphenytoin group and more deaths occurred in the levetiracetam group than in the other groups, but these differences were not significant.

CONCLUSIONS

In the context of benzodiazepine-refractory convulsive status epilepticus, the anticonvulsant drugs levetiracetam, fosphenytoin, and valproate each led to seizure cessation and improved alertness by 60 minutes in approximately half the patients, and the three drugs were associated with similar incidences of adverse events. (Funded by the National Institute of Neurological Disorders and Stroke; ESETT ClinicalTrials.gov number, NCT01960075.).

The WISDOM Personalized Breast Cancer Screening Trial: Simulation Study to Assess Potential Bias and Analytic Approaches

Background

WISDOM (Women Informed to Screen Depending on Measures of Risk) is a randomized trial to assess whether personalized breast cancer screening—where women are screened biannually, annually, biennially, or not at all depending on risk and age—can prevent as many advanced (stage IIB or higher) cancers as annual screening in women ages 40–74 years across 5 years of trial time. The short study time in combination with design choices of not requiring study entry and exit mammograms for all participants may introduce different sources of bias in favor of either the personalized or the annual arm.

Methods

We designed a simulation model and performed 5000 virtual WISDOM trials to assess potential biases. Each virtual trial simulated 65 000 randomly assigned participants who were each assigned a risk stratum and a time to stage of at least IIB cancer sampled from an exponential distribution with the hazard rate based on the risk stratum. Results from the virtual trials were used to evaluate two candidate analysis strategies with respect to susceptibility for introducing bias: 1) difference between arms in total number of events over total trial time, and 2) difference in number of events within complete screening cycles.

Results

Based on the simulations, about 86 stage IIB or higher cancers will be detected within the trial and the total exposure time will be about 74 000 years in each arm. Potential ascertainment bias is introduced at study entry and exit. Analysis strategy 1 works better for the nonscreened stratum, whereas method 2 is considerably more unbiased for the strata of women screened biennially or every 6 months.

Conclusion

Combining the two candidate analysis approaches gives a reasonably unbiased analysis based on the simulations and is the method we will use for the primary analysis in WISDOM. Publishing the WISDOM analysis approach provides transparency and can aid the design and analysis of other individualized screening trials.

Inhaled steroids reduce pain and sVCAM levels in individuals with sickle cell disease: A triple-blind, randomized trial

Clinical and preclinical data demonstrate that altered pulmonary physiology (including increased inflammation, increased blood flow, airway resistance, and hyper-reactivity) is an intrinsic component of Sickle Cell Disease (SCD) and may contribute to excess SCD morbidity and mortality. Inhaled corticosteroids (ICS), a safe and effective therapy for pulmonary inflammation in asthma, may ameliorate the altered pulmonary physiologic milieu in SCD. With this single-center, longitudinal, randomized, triple-blind, placebo controlled trial we studied the efficacy and feasibility of ICS in 54 nonasthmatic individuals with SCD. Participants received once daily mometasone furoate 220 mcg dry powder inhalation or placebo for 16 weeks. The primary outcome was feasibility (the number who complete the trial divided by the total number enrolled) with prespecified efficacy outcomes including daily pain score over time (patient reported) and change in soluble vascular cell adhesion molecule (sVCAM) levels between entry and 8-weeks. For the primary outcome of feasibility, the result was 96% (52 of 54, 95% CI 87%-99%) for the intent-to-treat analysis and 83% (45 of 54, 95% CI 71%-91%) for the per-protocol analysis. The adjusted treatment effect of mometasone was a reduction in daily pain score of 1.42 points (95%CI 0.61-2.21, P = 0.001). Mometasone was associated with a reduction in sVCAM levels of 526.94 ng/mL more than placebo (95% CI 50.66-1003.23, P = 0.03). These results support further study of ICS in SCD including multicenter trials and longer durations of treatment. www.clinicaltrials.gov (NCT02061202).

Using Bayesian Adaptive Trial Designs for Comparative Effectiveness Research: A Virtual Trial Execution

BACKGROUND

Bayesian and adaptive clinical trial designs offer the potential for more efficient processes that result in lower sample sizes and shorter trial durations than traditional designs.

OBJECTIVE

To explore the use and potential benefits of Bayesian adaptive clinical trial designs in comparative effectiveness research.

DESIGN

Virtual execution of ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) as if it had been done according to a Bayesian adaptive trial design.

SETTING

Comparative effectiveness trial of antihypertensive medications.

PATIENTS

Patient data sampled from the more than 42 000 patients enrolled in ALLHAT with publicly available data.

MEASUREMENTS

Number of patients randomly assigned between groups, trial duration, observed numbers of events, and overall trial results and conclusions.

RESULTS

The Bayesian adaptive approach and original design yielded similar overall trial conclusions. The Bayesian adaptive trial randomly assigned more patients to the better-performing group and would probably have ended slightly earlier.

LIMITATIONS

This virtual trial execution required limited resampling of ALLHAT patients for inclusion in RE-ADAPT (REsearch in ADAptive methods for Pragmatic Trials). Involvement of a data monitoring committee and other trial logistics were not considered.

CONCLUSION

In a comparative effectiveness research trial, Bayesian adaptive trial designs are a feasible approach and potentially generate earlier results and allocate more patients to better-performing groups.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute.

Validity of Criteria Used to Evaluate Fingerstick Devices That Assess International Normalized Ratio

Background . Investigators commonly rely on unvalidated, mainly arithmetic criteria to predict if point-of-care fingerstick devices that assess International Normalized Ratio (INR) lead to the same warfarin dosing decisions as a standard measure. Methods . Criteria that predict warfarin dosing agreement between 2 INR measurements were evaluated using clinicians’ actual dosing decisions as the standard. Bayesian hierarchical modeling was used to rank the criteria by the proportion of correct dosing predictions and the magnitude of difference between actual and predicted dosing agreement. Results . The prediction criteria misclassified dosing agreement for between 19% and 38% of paired INR values (x̄x: 27%). The magnitude of misclassification varied inconsistently throughout the INR scale. Conclusion . The unvalidated criteria used to predict warfarin dosing agreement between 2 INR measurements are associated with large error. Warfarin dosing decisions should be measured directly in such assessments.

Simulation of various randomization strategies for a clinical trial in sickle cell disease

OBJECTIVE

To use numerical simulation to evaluate various randomization strategies for a clinical trial in sickle cell disease (SCD).

METHODS

The Inhaled Mometasone to Promote Reduction in Vaso-occlusive Events trial* is a randomized, controlled, feasibility study of inhaled mometasone for individuals with SCD who do not have asthma. The target sample size is 45 patients and one goal is to limit imbalance with respect to two important covariates (1) hydroxyurea use and (2) historical emergency department (ED) utilization. We compared three methods of patient allocation (simple randomization, block randomization, and biased-coin adaptive randomization) using numerical simulation (10 000 trials). The primary outcome measure was the proportion of simulated trials with numerically apparent differences in the two covariates: hydroxyurea use (binary) and ED utilization (three-level ordinal).

RESULTS

Overall, only 1.6% of simulated trials had any covariate comparison with P < 0.3 across groups for simple randomization, and 0% for both the block and adaptive randomization. In trials where the total sample size was 45 patients, the block randomization strategy achieved the greatest balance because participants were deterministically assigned to the treatment arm that balanced covariates. The adaptive strategy achieved similar results without deterministic treatment assignments even when trials included only 45 patients.

DISCUSSION

Adaptive clinical trial designs have potential to mitigate some of the challenges that have hampered SCD trials. In small exploratory trials, even non-statistically significant differences in important covariates can threaten interpretability and external validity.

CONCLUSION

Adaptive randomization performed similarly to block randomization and offers advantages including better allocation concealment and less ability for investigators to predict the next assignment.

Percutaneous alternative to the Maze procedure for the treatment of persistent or long-standing persistent atrial fibrillation (aMAZE trial): Rationale and design

BACKGROUND

Pulmonary vein antrum isolation (PVI) as a treatment of paroxysmal atrial fibrillation (AF) is associated with a high rate of success; however, outcomes for treating persistent and long-standing persistent AF with PVI alone are substantially lower and often require multiple procedures to maintain long-term freedom from atrial arrhythmias. Foci and/or substrate outside the pulmonary veins, particularly in the left atrial appendage (LAA), has been identified as a key mechanism in the maintenance of persistent AF and long-standing persistent AF.

OBJECTIVE

The goals of the study are to evaluate the safety and effectiveness of the LARIAT System to percutaneously isolate and ligate the LAA and to determine if LAA ligation as adjunctive therapy to PVI improves maintenance of sinus rhythm in patients with persistent and long-standing persistent AF.

STUDY DESIGN

The trial is a prospective, multicenter, randomized controlled study. The trial design incorporates a Bayesian adaptive design that will randomize a maximum of 600 patients with persistent or long-standing persistent AF to LAA ligation and PVI vs PVI alone in a 2:1 randomization. The primary end points include 30-day safety of the LARIAT procedure and freedom from documented AF, atrial flutter, or atrial tachycardia of more than 30 seconds at 12 months after the PVI off antiarrhythmic drugs. Key secondary outcomes include a composite of cardiovascular death and stroke, as well as quality of life.

CONCLUSION

The aMAZE trial will determine if LAA ligation as adjunctive therapy to PVI increases the efficacy of maintaining sinus rhythm in patients with persistent and long-standing persistent AF.

The Stroke Hyperglycemia Insulin Network Effort (SHINE) trial: an adaptive trial design case study

Background

The ‘Adaptive Designs Accelerating Promising Trials into Treatments (ADAPT-IT)’ project is a collaborative effort supported by the National Institutes of Health (NIH) and United States Food & Drug Administration (FDA) to explore how adaptive clinical trial design might improve the evaluation of drugs and medical devices. ADAPT-IT uses the National Institute of Neurologic Disorders & Stroke-supported Neurological Emergencies Treatment Trials (NETT) network as a ‘laboratory’ in which to study the development of adaptive clinical trial designs in the confirmatory setting. The Stroke Hyperglycemia Insulin Network Effort (SHINE) trial was selected for funding by the NIH-NINDS at the start of ADAPT-IT and is currently an ongoing phase III trial of tight glucose control in hyperglycemic acute ischemic stroke patients. Within ADAPT-IT, a Bayesian adaptive Goldilocks trial design alternative was developed.

Methods

The SHINE design includes response adaptive randomization, a sample size re-estimation, and monitoring for early efficacy and futility according to a group sequential design. The Goldilocks design includes more frequent monitoring for predicted success or futility and a longitudinal model of the primary endpoint. Both trial designs were simulated and compared in terms of their mean sample size and power across a range of treatment effects and success rates for the control group.

Results

As simulated, the SHINE design tends to have slightly higher power and the Goldilocks design has a lower mean sample size. Both designs were tuned to have approximately 80% power to detect a difference of 25% versus 32% between control and treatment, respectively. In this scenario, mean sample sizes are 1,114 and 979 for the SHINE and Goldilocks designs, respectively.

Conclusions

Two designs were brought forward, and both were evaluated, revised, and improved based on the input of all parties involved in the ADAPT-IT process. However, the SHINE investigators were tasked with choosing only a single design to implement and ultimately elected not to implement the Goldilocks design. The Goldilocks design will be retrospectively executed upon completion of SHINE to later compare the designs based on their use of patient resources, time, and conclusions in a real world setting.

Trial registration

ClinicalTrials.gov NCT01369069 June 2011.

Not too big, not too small: a goldilocks approach to sample size selection

We present a Bayesian adaptive design for a confirmatory trial to select a trial's sample size based on accumulating data. During accrual, frequent sample size selection analyses are made and predictive probabilities are used to determine whether the current sample size is sufficient or whether continuing accrual would be futile. The algorithm explicitly accounts for complete follow-up of all patients before the primary analysis is conducted. We refer to this as a Goldilocks trial design, as it is constantly asking the question, "Is the sample size too big, too small, or just right?" We describe the adaptive sample size algorithm, describe how the design parameters should be chosen, and show examples for dichotomous and time-to-event endpoints.

The utility of Bayesian predictive probabilities for interim monitoring of clinical trials

BACKGROUND

Bayesian predictive probabilities can be used for interim monitoring of clinical trials to estimate the probability of observing a statistically significant treatment effect if the trial were to continue to its predefined maximum sample size.

PURPOSE

We explore settings in which Bayesian predictive probabilities are advantageous for interim monitoring compared to Bayesian posterior probabilities, p-values, conditional power, or group sequential methods.

RESULTS

For interim analyses that address prediction hypotheses, such as futility monitoring and efficacy monitoring with lagged outcomes, only predictive probabilities properly account for the amount of data remaining to be observed in a clinical trial and have the flexibility to incorporate additional information via auxiliary variables.

LIMITATIONS

Computational burdens limit the feasibility of predictive probabilities in many clinical trial settings. The specification of prior distributions brings additional challenges for regulatory approval.

CONCLUSIONS

The use of Bayesian predictive probabilities enables the choice of logical interim stopping rules that closely align with the clinical decision-making process.

Combining risk difference and risk ratio in noninferiority trials of safety

Prior to marketing, the long-term safety profile of a new therapy is often uncertain. One recommendation for premarket safety studies is to compare the new therapy to an appropriate control to determine whether the 95% confidence interval of the risk ratio is entirely less than a prespecified threshold (e.g., 1.8). The restriction to the risk ratio, however, has consequences that may not be intended. Risk difference may be a more appropriate measure of risk in this setting when event rates are very low. We propose using a suitable combination of risk ratio and risk difference in demonstrating noninferiority.

Bayesian adaptive trials offer advantages in comparative effectiveness trials: an example in status epilepticus

OBJECTIVE

We present a novel Bayesian adaptive comparative effectiveness trial comparing three treatments for status epilepticus that uses adaptive randomization with potential early stopping.

STUDY DESIGN AND SETTING

The trial will enroll 720 unique patients in emergency departments and uses a Bayesian adaptive design.

RESULTS

The trial design is compared to a trial without adaptive randomization and produces an efficient trial in which a higher proportion of patients are likely to be randomized to the most effective treatment arm while generally using fewer total patients and offers higher power than an analogous trial with fixed randomization when identifying a superior treatment.

CONCLUSION

When one treatment is superior to the other two, the trial design provides better patient care, higher power, and a lower expected sample size.

Do Bayesian adaptive trials offer advantages for comparative effectiveness research? Protocol for the RE-ADAPT study

BACKGROUND

Randomized clinical trials, particularly for comparative effectiveness research (CER), are frequently criticized for being overly restrictive or untimely for health-care decision making.

PURPOSE

Our prospectively designed REsearch in ADAptive methods for Pragmatic Trials (RE-ADAPT) study is a 'proof of concept' to stimulate investment in Bayesian adaptive designs for future CER trials.

METHODS

We will assess whether Bayesian adaptive designs offer potential efficiencies in CER by simulating a re-execution of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study using actual data from ALLHAT.

RESULTS

We prospectively define seven alternate designs consisting of various combinations of arm dropping, adaptive randomization, and early stopping and describe how these designs will be compared to the original ALLHAT design. We identify the one particular design that would have been executed, which incorporates early stopping and information-based adaptive randomization.

LIMITATIONS

While the simulation realistically emulates patient enrollment, interim analyses, and adaptive changes to design, it cannot incorporate key features like the involvement of data monitoring committee in making decisions about adaptive changes.

CONCLUSION

This article describes our analytic approach for RE-ADAPT. The next stage of the project is to conduct the re-execution analyses using the seven prespecified designs and the original ALLHAT data.

Abstract TP236: The Stroke Hyperglycemia Insulin Network Effort (SHINE) Trial: A Case Study of a Bayesian Trial Design

Introduction: The “Adaptive Designs Accelerating Promising Trials into Treatments (ADAPT-IT)” project is a collaborative effort supported by the NIH and FDA to explore how adaptive clinical trial design might improve the evaluation of drugs and medical devices. We use the NINDS-supported Neurological Emergencies Treatment Trials network as a "laboratory" in which to study the development of adaptive clinical trial designs. The Stroke Hyperglycemia Insulin Network Effort (SHINE) trial was fully funded by the NIH-NINDS at the start of ADAPT-IT and is a currently ongoing phase III trial of tight glucose control in hyperglycemic acute ischemic stroke patients. Within ADAPT-IT, a Bayesian alternative design was developed. The primary endpoint is a severity-adjusted dichotomized 90-day modified Rankin scale (mRS).

Objective: To present both designs and compare their operating characteristics.

Methods: 10000 trials are simulated under treatment effects ranging from 0% to 7%. We present the mean sample size and probabilities of trial success or futility.

Results: The SHINE trial design includes a group sequential procedure with 4 interim analyses to monitor for early efficacy and futility. A maximum of 1400 patients provide 80% power to detect a 7% absolute difference between treatment arms with an overall Type I error rate of 5%. The expected sample size is 1050 patients. This design also incorporates sample size re-estimation and response adaptive randomization. The Bayesian alternative would enroll a maximum of 1400 patients, equally randomized, but employs more frequent interim looks based on predictive probabilities and incorporates a longitudinal model of the primary endpoint. This design has similar power and Type I error and would enroll a mean of 733 and 979 patients under the null and alternative hypotheses respectively.

Conclusions: Simulations suggest that the designs have similar power and Type I error. The Bayesian alternative, with more frequent looks, has a greater chance of stopping early for overwhelming efficacy or futility. The Bayesian alternative will be retrospectively executed upon completion of SHINE to later compare the designs based on their use of patient resources, time, and strength of conclusions in a real world setting.

Application of adaptive design and decision making to a phase II trial of a phosphodiesterase inhibitor for the treatment of intermittent claudication

Background

Claudication secondary to peripheral artery disease (PAD) is associated with substantial functional impairment. Phosphodiesterase (PDE) inhibitors have been shown to increase walking performance in these patients. K-134 is a selective PDE 3 inhibitor being developed as a potential treatment for claudication. The use of K-134, as with other PDE 3 inhibitors, in patients with PAD raises important safety and tolerability concerns, including the induction of cardiac ischemia, tachycardia, and hypotension. We describe the design, oversight, and implementation of an adaptive, phase II, dose-finding trial evaluating K-134 for the treatment of stable, intermittent claudication.

Methods

The study design was a double-blind, multi-dose (25 mg, 50 mg, and 100 mg of K-134), randomized trial with both placebo and active comparator arms conducted in the United States and Russia. The primary objective of the study was to compare the highest tolerable dose of K-134 versus placebo using peak walking time after 26 weeks of therapy as the primary outcome. Study visits with intensive safety assessments were included early in the study period to provide data for adaptive decision making. The trial used an adaptive, dose-finding strategy to efficiently identify the highest dose(s) most likely to be safe and well tolerated, based on the side effect profiles observed within the trial, so that less promising doses could be abandoned. Protocol specified criteria for safety and tolerability endpoints were used and modeled prior to the adaptive decision making. The maximum target sample size was 85 subjects in each of the retained treatment arms.

Results

When 199 subjects had been randomized and 28-day data were available from 143, the Data Monitoring Committee (DMC) recommended termination of the lowest dose (25 mg) treatment arm. Safety evaluations performed during 14- and 28-day visits which included in-clinic dosing and assessments at peak drug concentrations provided core data for the DMC review. At the time of review, no subject in any of the five treatment arms (placebo, three K-134-containing arms, and cilostazol) had met pre-specified definitions for resting tachycardia or ischemic changes on exercise ECG. If, instead of dropping the 25-mg K-134 treatment arm, all arms had been continued to full enrollment, then approximately 43 additional research subjects would have been required to complete the trial.

Conclusions

In this phase II, dose-finding trial of K-134 in the treatment of stable intermittent claudication, no concerning safety signals were seen at interim analysis, allowing the discontinuation of the lowest-dose-containing arm and the retention of the two highest-dose-containing arms. The adaptive design facilitated safe and efficient evaluation of K-134 in this high-risk cardiovascular population.

Trial registration

ClinicalTrials.gov: NCT00783081

Clinical decision-making as the basis for assessing agreement between measures of the International Normalized Ratio

BACKGROUND

The now classic approach of Bland and Altman is often used to assess the level of agreement between International Normalized Ratio (INR) measures. However, we are concerned that this method does not define agreement in a clinically meaningful way. Agreement between measures should be characterized explicitly in terms of clinical decisions that result from INR measures.

OBJECTIVES

To develop and validate an extension of the Bland-Altman method to assess agreement between INR measures, based explicitly on the way clinicians make decisions.

METHODS AND RESULTS

We developed a clinically based graphical method to estimate the level of agreement between measures of INR. We identified clinically relevant INR ranges using epidemiologic and clinical evidence regarding risk and expected outcome at different INR ranges. Clinical decisions were expected to agree within these INR ranges and, therefore, the ranges became the basis for establishing agreement between measures. We used paired INR measures and resultant clinical decisions measured during a previous prospective study to validate and compare the accuracy of our model to those of Bland and Altman's and other published models. Our method more accurately predicts when warfarin dosing decisions differ than the Bland-Altman method (P < 0.02). Our method is also superior to other published methods, particularly at the important task of identifying when measures lead to discrepant clinical decisions.

CONCLUSIONS

We introduced and validated an improvement of the Bland-Altman method to assess agreement between INR measures. Our model is superior because it is based explicitly on factors that influence clinical decision-making.

Positive reasons for publishing negative findings

Scientific and medical authors tend to be biased toward submitting "statistically significant" findings for publication. Journals show a similar bias in publishing such "positive" studies. The large number of publications in medical research means that, in a field obsessed with controlling Type I error rates, we have journals with an abundance of Type I errors. Failing to publish studies that do not show a treatment or exposure effect creates a literature conspicuously absent of trials necessary for unbiased meta-analyses and systematic reviews. Furthermore, by shelving or rejecting studies with nonstatistically significant outcomes, authors and editors censor the most important contributors to medical research: our consenting volunteers.

Alcohol consumption by cirrhotic subjects: patterns of use and effects on liver function

OBJECTIVE

We investigated patterns of use of alcohol and its clinical effects among cirrhotic subjects who participated in a randomized clinical trial comparing the efficacy of transjugular intravenous portosystemic shunt and distal splenorenal shunt.

METHODS

There were 132 cirrhotic subjects, 78 with alcoholic liver disease (ALD), who were followed for a median of 49 months (range 2-93 months). Alcohol use was assessed by patient questionnaire, with corroboration by family members.

RESULTS

Twenty-eight subjects (21%) were drinking at study entry and 60 subjects (45%) drank during follow-up. Heavy drinking (>4 drinks/day) was recorded in 25 ALD subjects, but in no non-ALD subjects (P < 0.0001). Drinking by ALD subjects was associated with a 153% increase in gamma-glutamyl transpeptidase (GGT) (P < 0.0001). The frequencies of death (46%vs 30%), ascites (33%vs 20%), encephalopathy (56%vs 42%), and variceal bleeding (11%vs 3%) were greater in the ALD group. In a Cox proportional hazards model only "ever heavy drinking" was associated with death (P= 0.0099), while recent heavy drinking increased the hazard of variceal hemorrhage dramatically (odds ratio 10.85).

CONCLUSIONS

Whereas most cirrhotic subjects, alcoholic or not, did not drink during 5 yr of observation, heavy alcohol use occurred exclusively in ALD patients. Alcohol use by ALD subjects was associated with elevations in GGT and was linked to death and with rebleeding from shunt dysfunction.

Colonoscopy preparation: are our patients at risk?

Clinical studies are used to make generalizations about a population of interest. Bias can be defined as the systematic error in study design or implementation, leading to inaccurate generalizations about this population. There is a potential for bias in all of the clinical studies on sodium phosphate colonoscopy preparation, and this bias may lead to the differing conclusions regarding safety drawn by the authors. A review of some of the relevant literature is presented, as well as a discussion of propensity score analysis, a technique used to help clarify the causal pathway in nonrandomized studies. Based on the available information, it is reasonable to follow the recommendations contained in the consensus document of the American Society of Colon and Rectal Surgeons, American Society for Gastrointestinal Endoscopy, and Society of American Gastrointestinal and Endoscopic Surgeons regarding sodium phosphate colonoscopy preparation.

A Brief Risk Stratification Tool to Predict Functional Decline in Older Adults Discharged from Emergency Departments

OBJECTIVES

To determine the effectiveness of the six-item Triage Risk Screening Tool (TRST) to assess baseline functional status and predict subsequent functional decline in older community-dwelling adults discharged home from the emergency department (ED).

DESIGN

Secondary data analysis of a randomized, controlled trial.

SETTING

EDs of two urban academic hospitals.

PARTICIPANTS

Six hundred fifty community-dwelling adults aged 65 and older presenting to the ED and discharged home. Patients were categorized a priori as "high risk" if they had cognitive impairment or two or more risk factors on the TRST.

MEASUREMENTS

Functional status: summed activity of daily living (ADL) and instrumental activity of daily living (IADL) scores at baseline, 30 days, and 120 days. Self-perceived physical health: standardized physical health component of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Functional decline: loss of one or more ADLs and one or more IADLs from ED baseline at 30 and 120 days. Decline in self-perceived physical health: follow-up SF-36 standardized physical health component scores four or more points lower than baseline.

RESULTS

TRST scores correlated with baseline ADL impairments, IADL impairments, and self-perceived physical health at all endpoints (P<.001). A TRST score of two or more was moderately predictive of decline in ADLs or IADLs (30-day ADL area under the receiver operating characteristic curve (AUC)=0.64; 95% confidence interval (CI)=0.56-0.72; 120-day ADL AUC=0.66; 95% CI=0.58-0.74) but not perceived physical health.

CONCLUSION

The TRST identifies baseline functional impairment in older ED patients and is moderately predictive of subsequent functional decline after an initial ED visit. The TRST provides a valid proxy measure for assessing functional status in the ED and may be useful in identifying high-risk patients who would benefit from referrals for further evaluation or surveillance upon ED discharge.

Barrett's esophagus in women: demographic features and progression to high-grade dysplasia and cancer

BACKGROUND & AIMS

Barrett's esophagus is traditionally considered a disease of older white men. The aims of this study were to compare the demographic features of Barrett's esophagus in men and women and to determine the prevalence and incidence of high-grade dysplasia and cancer in these patients.

METHODS

All patients enrolled in the Cleveland Clinic Barrett's Esophagus Registry from 1979-2002 were studied. Age, ethnicity, number of endoscopies, hiatal hernia size, length of Barrett's segment, and prevalence and incidence of high-grade dysplasia and cancer were compared between men and women.

RESULTS

There were 839 patients in the registry (628 men and 211 women). Barrett's segment length was greater in men than in women (mean, 5.06 +/- 4.2 vs 4.05 +/- 3.27 cm, respectively; P = .003). There were no significant differences for other parameters. There were 114 prevalence cases of high-grade dysplasia or cancer (96 men, 18 women). Women were less likely to have prevalent high-grade dysplasia or cancer than men (odds ratio, 0.52; 95% confidence interval, 0.31-0.88; P = .015). There were 13 incidence cases of high-grade dysplasia or cancer (11 men, 2 women) during a mean follow-up of 4.72 years, which was similar in both genders with an incidence rate of 1 in 179 patient-years of follow-up for women and 1 in 91 patient-years of follow-up in men.

CONCLUSIONS

Twenty-five percent of patients in our registry are women. The length of Barrett's esophagus is greater in men than in women, but other features are similar. The prevalence of high-grade dysplasia/cancer in women is approximately half that of men. Incidence rates for high-grade dysplasia/cancer are similar in men and women, although the number of cases is small.

Male sexual function improves after ileal pouch anal anastomosis

PURPOSE

Restorative Proctocolectomy and Ileal Pouch Anal Anastomosis has become the gold standard surgical therapy for the majority of patients with mucosal ulcerative colitis. However sexual functional disturbances after this procedure can be a concern for patients. Therefore the aim of this study was to determine the outcome of sexual-function related quality of life in male patients undergoing restorative proctocolectomy.

METHODS

One hundred and twenty-two male patients who underwent restorative proctocolectomy with ileal pouch anal anastomosis between 1995 and 2000 were evaluated by the validated International Index of Erectile Function (IIEF) scoring instrument. This index scale examines sexual function in five categories. These are erectile function, orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction. The IIEF instrument was administered after surgery and then scores before and after RP/IPAA were evaluated and compared. The significance of age at the time of the surgery, type of surgery, type of anastomotic technique (mucosectomy vs stapled) and septic complications on sexual functional outcome were also investigated.

RESULTS

Mean age at the time of the surgery was 39.9 +/- 11.5 years. The mean follow-up period (time between pouch surgery and IIEF completed) was 3.6 +/- 1.8 years. There was statistically significant improvement in 4 of 5 categories of sexual function (erectile function, sexual desire, intercourse satisfaction, and overall satisfaction) where patients had improved scores after surgery compared to prior to surgery. The mean erectile function score increased pre to post surgery by 2.12 points (P = 0.02), which indicates better sexual results. Anastomotic technique and septic complication did not influence the results, however, older age had a negative impact on results.

CONCLUSIONS

Despite some adverse sexual functions, male patients who undergo RP/IPAA for the surgical management of their colitis may preserve or improve their overall sexual functional outcome.

Human defensin 5 expression in intestinal metaplasia of the upper gastrointestinal tract

BACKGROUND

Upper gastrointestinal tract intestinal metaplasia (IM) is termed Barrett's oesophagus (BO) or gastric intestinal metaplasia (GIM), depending on its location. BO and GIM are associated with chemical exposure resulting from gastro-oesophageal reflux and chronic Helicobacter pylori infection, respectively. Paneth cells (PCs), characterised by cytoplasmic eosinophilic granules, are found in a subset of IM at these sites, but histology may not accurately detect them.

AIM

To determine human defensin 5 (HD5; an antimicrobial peptide produced by PCs) expression in BO and GIM, and to investigate its association with H pylori infection.

METHODS

Endoscopic biopsies from 33 patients with BO and 51 with GIM, and control tissues, were examined by routine histology and for H pylori infection and HD5 mRNA and protein expression.

RESULTS

In normal tissues, HD5 expression was specific for PCs in the small intestine. Five patients with BE and 42 with GIM expressed HD5, but few HD5 expressing cells in IM had the characteristic histological features of PCs. Most HD5 positive specimens were H pylori infected and most HD5 negative specimens were not infected.

CONCLUSIONS

HD5 immunohistochemistry was often positive in IM when PCs were absent by conventional histology. Thus, HD5 immunohistochemistry may be superior to histology for identifying metaplastic PCs and distinguishing GIM from BO. The higher frequency of HD5 expression in GIM than in BO is associated with a higher frequency of H pylori infection, suggesting that in IM PCs may form part of the mucosal antibacterial response.

Neonates with hypoplastic left heart syndrome have ultrasound evidence of abnormal superior mesenteric artery perfusion before and after modified Norwood procedure

OBJECTIVE

To a) describe superior mesenteric artery resistive index, as an estimate of perfusion, before and after modified Norwood; and b) assess incidence of diastolic flow reversal in the superior mesenteric artery before and after modified Norwood.

DESIGN

Prospective observational trial.

SETTING

Children's hospital pediatric intensive care unit.

PATIENTS

Ten newborns with hypoplastic left heart syndrome.

INTERVENTIONS

Ultrasound documentation of superior mesenteric artery diastolic flow direction and measurement of superior mesenteric artery resistive index 24-48 hrs before and 24-48 hrs after modified Norwood.

MEASUREMENTS AND MAIN RESULTS

Seven males and three females were enrolled. There was no change between the superior mesenteric artery resistive index pre- vs. postoperatively-0.99 (95% confidence interval, 0.85, 1.12) vs. 1.07 (95% confidence interval, 1.0, 1.15) (p = .13). Incidence of retrograde diastolic blood flow in the superior mesenteric artery was not different pre- vs. postoperatively (70% vs. 50%, p = .41). No patients developed necrotizing enterocolitis and all survived to hospital discharge.

CONCLUSIONS

Ultrasound measurements in neonates with hypoplastic left heart syndrome suggest that superior mesenteric artery perfusion, as measured by resistive index, is impaired. Superior mesenteric artery diastolic flow reversal is common before and immediately after modified Norwood.

Myocardial compliance was not altered after acute induction of atrial fibrillation in sheep

BACKGROUND

Although left ventricular (LV) contractility in atrial fibrillation (Af) is known to change in a beat-to-beat fashion, little is known about the changes in LV compliance in Af.

MATERIAL/METHODS

We experimentally induced tachycardic Af (average heart rate - 154 beats per minute) in 18 sheep. LV volume and pressure were simultaneously monitored using a conductance catheter. LV end-diastolic volume (V(ED)) and pressure (P(ED)) were plotted in a beat-to-beat fashion and fitted to the following exponential equation (P(ED)=gamma x e(b x V(ED))) in each animal. A random effects model was constructed to determine if the intercepts and slopes differ.

RESULTS

In all animals, those plots after the induction of Af fit quite well to the exponential function (r=0.834+/-0.184) by gating short preceding interval (RR1) beats. By simply taking the natural logarithm of both sides in the equation, the linear relationship (ln(P(ED)) =alpha+ betaxV(ED), where a = lng) was observed in all animals before (normal sinus rhythm, NSR) and after the induction of Af. Only two of 18 intercepts and four of 18 slopes deviate between NSR and Af. Most interestingly, the random effects model clearly detailed that the average animal had intercepts and slopes that were not discernibly different between NSR and Af.

CONCLUSIONS

Unlike LV contractility, myocardial compliance did not change after the acute induction of Af. These interesting results may give us insights into the understanding of the physiology in acute rapid Af.

Immunohistochemical detection and Western blot analysis of nitrated protein in stored human corneal epithelium

While the production of nitric oxide by human corneas in storage has recently been demonstrated, protein nitration as a result of this production has not been demonstrated. In this study, nitrated protein accumulation in the epithelium of stored human corneas was assessed. One half of five donor corneas maintained in storage media for 3 days were prepared for immunohistochemical studies. The other halves remained in storage media for 7 additional days and were also processed for immunohistochemistry. Mouse monoclonal antibody to nitrotyrosine adducts was used to define the localisation of these epitopes. The density of antibody staining was observed and quantified on a digital camera system and statistically analysed. Immunostaining in the epithelium was greater in tissues recovered after 10 days in storage compared to the intensity of staining after 3 days of storage (p<0.0001). No staining was evident in the epithelium in sections exposed to non-immune mouse IgG. Western blot analysis was performed on epithelial cells scraped from corneal surfaces of one-half of four donor corneas in storage for 3 days and from the other half at 10 days of storage. Nitrated BSA was used as a positive control. After extraction and homogenisation, identical protein concentrations of each sample were loaded per lane on 10% gels and subjected to SDS-PAGE. Proteins were blotted and probed with the anti-nitrotyrosine antibody. Western blot immunoreactivity was detected in epithelial samples at the 3 and 10 day recovery times with the latter samples showing greater staining intensity. Nitrated protein, thought to indicate toxic peroxynitrite formation, accumulates in the human corneal epithelium with time of storage. Our study shows that there is an association between increased nitrated protein and storage time.

Randomized controlled trial comparing the controlled rehabilitation with early ambulation and diet pathway versus the controlled rehabilitation with early ambulation and diet with preemptive epidural anesthesia/analgesia after laparotomy and intestinal resection

BACKGROUND

Multimodal postoperative care regimens accelerate recovery after abdominal surgery. The benefit of thoracic epidural (TE) analgesia over patient-controlled analgesia (PCA) remains unproven when used with a fast-track postoperative care plan.

METHODS

Fifty-six patients undergoing major intestinal resection, and on a fast-track postoperative care plan, were randomized to preemptive TE or PCA. Patients were evaluated at standard time points for pain score, quality of life (Short Form-36), and complications. Oral analgesia was substituted for TE and PCA on the second postoperative day. Discharge criteria were identical for both groups.

RESULTS

Six patients (20.6%) had a failed epidural. There was no difference in length of stay (5.8 versus 6.2 days, TE versus PCA, P = .55), total length of stay (including readmissions), pain scores, quality of life, complications, or hospital costs at any time point.

CONCLUSION

TE offers no advantage over PCA for patients undergoing major intestinal resections who are on a fast-track postoperative care plan using PCA.

Pre-to-post race changes in self-reported depression scores in ultra-distance triathletes - a pilot study

SA Sports Medicine Vol.15(3) 2003: 11-16

In vivo colonoscopic optical coherence tomography for transmural inflammation in inflammatory bowel disease

BACKGROUND & AIMS

Transmural inflammation, a distinguishing feature of Crohn's disease (CD), cannot be assessed by conventional colonoscopy with mucosal biopsy. Our previous ex vivo study of histology-correlated optical coherence tomography (OCT) imaging on colectomy specimens of CD and ulcerative colitis (UC) showed that disruption of the layered structure of colon wall on OCT is an accurate marker for transmural inflammation of CD. We performed an in vivo colonoscopic OCT in patients with a clinical diagnosis of CD or UC using the previously established, histology-correlated OCT imaging criterion.

METHODS

OCT was performed in 40 patients with CD (309 images) and 30 patients with UC (292 images). Corresponding endoscopic features of mucosal inflammation were documented. Two gastroenterologists blinded to endoscopic and clinical data scored the OCT images independently to assess the feature of disrupted layered structure.

RESULTS

Thirty-six CD patients (90.0%) had disrupted layered structure, whereas 5 UC patients (16.7%) had disrupted layered structure (P < .001). Using the clinical diagnosis of CD or UC as the gold standard, the disrupted layered structure on OCT indicative of transmural inflammation had a diagnostic sensitivity and specificity of 90.0% (95% CI: 78.0%, 96.5%) and 83.3% (95% CI: 67.3%, 93.3%) for CD, respectively. The kappa coefficient in the interpretation of OCT images was 0.80 (95% CI: 0.75, 0.86, P < .001).

CONCLUSIONS

In vivo colonoscopic OCT is feasible and accurate to detect disrupted layered structure of the colon wall indicative of transmural inflammation, providing a valuable tool to distinguish CD from UC.

Clinical outcome and factors predictive of recurrence after enterocutaneous fistula surgery

OBJECTIVE

Recent experience with surgery for enterocutaneous fistulae (ECF) at a specialist colorectal unit is reviewed to define factors relating to a successful surgical outcome.

SUMMARY BACKGROUND DATA

ECF cause significant morbidity and mortality and need experienced surgical management. Previous publications have concentrated on mortality resulting from fistulae, while factors affecting recurrence have not previously been a focus of analysis.

METHODS

Records were reviewed of patients who had ECF surgery (1994-2001). Management strategy involved early drainage of sepsis and nutritional support prior to elective ECF repair, with selective defunctioning proximal stoma formation.

RESULTS

A total of 205 patients were available (89 males, 43%; median age, 51 years; range, 16-86) years). ECF were related to Crohn's disease in 95, ulcerative colitis in 18, diverticular disease in 17, carcinoma in 25 (16 after radiotherapy), mesh ventral hernia repair in 21, and other causes in 29. Forty-one (20%) had undergone attempted fistula repair at other institutions. Initial management included CT-guided drainage of an intra-abdominal abscess in 23 patients, and total parenteral nutrition in 74 (36%). A total of 203 patients had definitive ECF repair. Forty-four had oversewing or wedge resection of the fistula, and 159 had resection and reanastomosis of the involved small bowel segment or ileocolic anastomosis. Ninety-day operative mortality was 3.5%. A total of 42 (20.5%) patients developed ECF recurrence within 3 months. Multivariate analysis demonstrated that recurrence was more likely after oversewing (36%) than resection (16%, P = 0.006).

CONCLUSIONS

A strategy of drainage of acute sepsis, maintenance of nutritional support prior to surgery, and selective use of PS allows for primary closure in 80% of complicated ECF. Resection should be performed when feasible.

Pneumatic dilation for the treatment of achalasia in untreated patients and patients with failed Heller myotomy

BACKGROUND

Laparoscopic Heller myotomy (HM) has become an increasingly preferred modality to treat achalasia. However, the treatment course after a failed myotomy is controversial with fears that pneumatic dilation (PD) has high perforation risk.

GOAL

To compare success and safety of graded PD with Rigiflex balloons in achalasia patients without a prior HM (untreated cases) and those with a failed HM.

STUDY

A total of 108 patients were retrospectively evaluated: 96 untreated cases (53 male, 43 female, mean age 51 years) and 12 failed HM(7 male, 5 female, mean age 54 years). Symptoms (dysphagia and regurgitation) and physiologic studies, lower esophageal sphincter pressure (LESP) and timed barium swallow, assessed pre- and post-PD. Success was defined as: 1) symptom improvement to </=2 to 4 times per week, and 2) >/=80% decrease in 5-minute barium column height from initial timed barium swallow.

RESULTS

A total of 139 PDs performed (117 untreated cases, 22 failed HM): 2 perforations in untreated cases and none in failed HM group. Baseline demographics were similar, but failed HM patients had significantly lower LESP and timed barium swallow columns. Despite less LES resistance, failed HM group (symptom and physiologic success: 50% and 10%) did not do as well after PD as compared with untreated cases (symptom and physiologic success: 74% and 52%, respectively). Five failed HM patients had good symptom relief after PD compared with poor responders these patients were older (>50 years) and had LESP >17 mm Hg.

CONCLUSIONS

PD perforation risk is not higher after HM. Despite lower LES pressure, patients undergoing PD after failed HM do not do as well as untreated cases. Factors predicting better outcome include older age and higher LES pressure.

The value of a p-valueless paper

As is common in current biomedical research, about 85% of original contributions in The American Journal of Gastroenterology in 2004 have reported p-values. However, none are reported in this issue's article by Abraham et al. who, instead, rely exclusively on effect size estimates and associated confidence intervals to summarize their findings. Authors using confidence intervals communicate much more information in a clear and efficient manner than those using p-values. This strategy also prevents readers from drawing erroneous conclusions caused by common misunderstandings about p-values. I outline how standard, two-sided confidence intervals can be used to measure whether two treatments differ or test whether they are clinically equivalent.

Benefits of 'clean sweep' in Peutz-Jeghers patients

OBJECTIVE

Laparotomy is the treatment of choice in Peutz-Jeghers Syndrome (PJS) patients for endoscopically irretrievable symptomatic polyps and polyp-related complications. During the last decade, we have operated on majority of the PJS patients with the purpose of removing all the gastrointestinal polyps (clean sweep), when an operation was indicated. The aim of this study is to evaluate the effect of clean sweep technique on the need for repeated surgery compared to a problem focused approach.

PATIENTS AND METHODS

All patients with PJS treated in our institution since 1964 were studied. They were placed into two groups; those who had a problem-focused operation and those who were operated with the purpose of removing all small and large intestinal polyps. Demographics, presentation, follow-up period and the need for recurrent surgery were compared.

RESULTS

We identified 11 patients (4 males, 7 females). Eight patients (5 females; median age 18.5) had problem-focused surgery for bleeding-anaemia (n = 3) or obstruction-intussusception (n = 5). These patients required 23 further operations within 87 patient-follow-up-years (2.64 operations per 10 years). Three patients (2 females; median age 6) were operated for bleeding-anaemia (n = 1) or obstruction-intussusception (n = 2) using the 'clean sweep' approach. These patients did not require any further surgery within 21 patient-follow-up-years. The gender, presentation and follow-up periods were similar between the groups. However, the 'clean sweep' technique appears to have reduced the need for further operations when it is compared with problem-focused approach (P = 0.01).

CONCLUSION

To reduce the need for abdominal surgery and consequent problems in PJS patients, an attempt to remove all detected polyps (clean sweep technique) may be beneficial in these patients.