Design of a phase III, double-blind, randomised, placebo-controlled trial of BI 1015550 in patients with progressive pulmonary fibrosis (FIBRONEER-ILD).

INTRODUCTION: Progressive pulmonary fibrosis (PPF) includes any diagnosis of progressive fibrotic interstitial lung disease (ILD) other than idiopathic pulmonary fibrosis (IPF). However, disease progression appears comparable between PPF and IPF, suggesting a similar underlying pathology relating to pulmonary fibrosis. Following positive results in a phase II study in IPF, this phase III study will investigate the efficacy and safety of BI 1015550 in patients with PPF (FIBRONEER-ILD). METHODS AND ANALYSIS: In this phase III, double-blind, placebo-controlled trial, patients are being randomised 1:1:1 to receive BI 1015550 (9 mg or 18 mg) or placebo twice daily over at least 52 weeks, stratified by background nintedanib use. Patients must be diagnosed with pulmonary fibrosis other than IPF that is progressive, based on predefined criteria. Patients must have forced vital capacity (FVC) ≥45% predicted and haemoglobin-corrected diffusing capacity of the lung for carbon monoxide ≥25% predicted. Patients must be receiving nintedanib for at least 12 weeks, or not receiving nintedanib for at least 8 weeks, prior to screening. Patients on stable treatment with permitted immunosuppressives (eg, methotrexate, azathioprine) may continue their treatment throughout the trial. Patients with clinically significant airway obstruction or other pulmonary abnormalities, and those using immunosuppressives that may confound FVC results (cyclophosphamide, tocilizumab, mycophenolate, rituximab) or high-dose steroids will be excluded. The primary endpoint is absolute change from baseline in FVC (mL) at week 52. The key secondary endpoint is time to the first occurrence of any acute ILD exacerbation, hospitalisation for respiratory cause or death, over the duration of the trial. ETHICS AND DISSEMINATION: The trial is being carried out in accordance with the ethical principles of the Declaration of Helsinki, the International Council on Harmonisation Guideline for Good Clinical Practice and other local ethics committees. The study results will be disseminated at scientific congresses and in peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT05321082.

Cardiovascular safety of nintedanib in subgroups by cardiovascular risk at baseline in the TOMORROW and INPULSIS trials.

Nintedanib is a tyrosine kinase inhibitor used to treat idiopathic pulmonary fibrosis (IPF). We investigated the cardiovascular safety of nintedanib using pooled data from the TOMORROW and INPULSIS trials.Cardiovascular events were assessed post hoc in patients with a history of atherosclerotic cardiovascular disease (CVD) and/or one or more cardiovascular risk factors at baseline ("higher cardiovascular risk") and patients with no history of atherosclerotic CVD and no cardiovascular risk factors at baseline ("lower cardiovascular risk").Incidence rates were calculated for 1231 patients (n=723 nintedanib and n=508 placebo), of whom 89.9% had higher cardiovascular risk. Incidence rates of major adverse cardiovascular events were similar in the nintedanib and placebo groups in patients with higher cardiovascular risk (3.88 (95% CI 2.58-5.84) and 3.49 (95% CI 2.10-5.79) per 100 patient-years, respectively) and lower cardiovascular risk (4.78 (95% CI 1.54-14.82) and 5.37 (95% CI 1.73-16.65) per 100 patient-years, respectively). Incidence rates of myocardial infarction in the nintedanib and placebo groups, respectively, were 3.03 (95% CI 1.91-4.81) and 1.16 (95% CI 0.48-2.79) per 100 patient-years in patients with higher cardiovascular risk and 1.59 (95% CI 0.22-11.29) and 1.78 (95% CI 0.25-12.64) per 100 patient-years in patients with lower cardiovascular risk. Incidence rates of other ischaemic heart disease in the nintedanib and placebo groups, respectively, were 1.85 (95% CI 1.02-3.34) and 3.28 (95% CI 1.94-5.54) per 100 patient-years in patients with higher cardiovascular risk and 0 and 1.80 (95% CI 0.25-12.78) per 100 patient-years in patients with lower cardiovascular risk.These data help to establish the cardiovascular safety profile of nintedanib in IPF.

Safety and survival data in patients with idiopathic pulmonary fibrosis treated with nintedanib: pooled data from six clinical trials.

Introduction: Nintedanib slows disease progression in patients with idiopathic pulmonary fibrosis (IPF) by reducing the rate of decline in forced vital capacity, with an adverse event profile that is manageable for most patients. We used data from six clinical trials to characterise the safety and tolerability profile of nintedanib and to investigate its effects on survival. Methods: Data from patients treated with ≥1 dose of nintedanib 150 mg two times per day or placebo in the 52-week TOMORROW trial and/or its open-label extension; the two 52-week INPULSIS trials and/or their open-label extension, INPULSIS-ON; and a Phase IIIb trial with a placebo-controlled period of ≥6 months followed by open-label nintedanib were pooled. All adverse events, irrespective of causality, were included in descriptive analyses. Parametric survival distributions were fit to pooled Kaplan-Meier survival data from the trials and extrapolated to estimate long-term survival. Results: There were 1126 patients in the pooled nintedanib group and 565 patients in the pooled placebo group. The mean duration of nintedanib treatment was 28 months. No new safety signals were observed. Incidence rates of bleeding, liver enzyme elevations and cardiovascular events were consistent with those observed in the INPULSIS trials. Diarrhoea was reported at a lower event rate in the pooled nintedanib group than in nintedanib-treated patients in the INPULSIS trials (76.5 vs 112.6 events per 100 patient exposure-years) and infrequently led to permanent treatment discontinuation (3.6 events per 100 patient exposure-years). Based on the Weibull distribution, mean (95% CI) survival was estimated as 11.6 (9.6, 14.1) years in nintedanib-treated patients and 3.7 (2.5, 5.4) years in placebo-treated patients. Conclusions: Based on pooled data from six clinical trials, the adverse event profile of nintedanib was manageable for most patients. Exploratory analyses based on extrapolation of survival data suggest that nintedanib extends life expectancy in patients with IPF.

Effects of nintedanib in patients with idiopathic pulmonary fibrosis by GAP stage.

We conducted a post hoc analysis to assess the potential impact of GAP (gender, age, physiology) stage on the treatment effect of nintedanib in patients with idiopathic pulmonary fibrosis. Outcomes were compared in patients at GAP stage I versus II/III at baseline in the INPULSIS® trials. At baseline, 500 patients were at GAP stage I (nintedanib 304, placebo 196), 489 were at GAP stage II (nintedanib 296, placebo 193) and 71 were at GAP stage III (nintedanib 38, placebo 33). In nintedanib-treated patients, the annual rate of decline in forced vital capacity (FVC) was similar in patients at GAP stage I and GAP stage II/III at baseline (-110.1 and -116.6 mL·year-1, respectively), and in both subgroups was lower than in placebo-treated patients (-218.5 and -227.6 mL·year-1, respectively) (treatment-by-time-by-subgroup interaction p=0.92). In the nintedanib group, the number of deaths was 43.8% of those predicted based on GAP stage (35 versus 79.9). In the placebo group, the number of deaths was 59.8% of those predicted based on GAP stage (33 versus 55.2). In conclusion, data from the INPULSIS® trials suggest that nintedanib has a similar beneficial effect on the rate of FVC decline in patients at GAP stage I versus II/III at baseline.

Investigating the effects of nintedanib on biomarkers of extracellular matrix turnover in patients with IPF: design of the randomised placebo-controlled INMARK®trial.

INTRODUCTION: A feature of the pathogenesis of idiopathic pulmonary fibrosis (IPF) is the excess accumulation of extracellular matrix (ECM) in the lungs. Cleavage of the ECM by metalloproteinases (MMPs) generates free-circulating protein fragments known as neoepitopes. The PROFILE study suggested that changes in ECM turnover proteins may be of value as markers of disease progression in patients with IPF. Nintedanib is an approved treatment for IPF that slows disease progression by reducing decline in forced vital capacity (FVC). METHODS AND ANALYSIS: The INMARK® trial is evaluating the effect of nintedanib on the rates of change of biomarkers of ECM turnover in patients with IPF, the value of changes in these biomarkers as predictors of disease progression and whether nintedanib affects the associations between changes in these biomarkers and disease progression. Following a screening period, 347 patients with IPF and FVC ≥80% predicted were randomised 1:2 to receive nintedanib 150 mg two times a day or placebo for 12 weeks, followed by an open-label period in which all patients will receive nintedanib for 40 weeks. The primary endpoint is the rate of change in C reactive protein degraded by MMP-1/8 from baseline to week 12. ETHICS AND DISSEMINATION: This trial is being conducted in compliance with the protocol, the ethical principles detailed in the Declaration of Helsinki and in accordance with the International Conference on Harmonisation Harmonised Tripartite Guideline for Good Clinical Practice. The results of the trial will be presented at national and international meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02788474.

Statin Therapy and Outcomes in Trials of Nintedanib in Idiopathic Pulmonary Fibrosis.

BACKGROUND: Cardiovascular comorbidities are frequent in patients with idiopathic pulmonary fibrosis (IPF), and many patients with IPF receive treatment with statins to reduce cardiovascular risk. OBJECTIVES: We investigated whether statin use at baseline was associated with differences in disease progression in placebo-treated patients or influenced the treatment effect of nintedanib in the INPULSIS® trials. METHODS: Post-hoc subgroup analyses of patients receiving versus not receiving statins at baseline using pooled data from the INPULSIS® trials. RESULTS: At baseline, 312 patients received statins and 749 did not. The annual rates of decline in forced vital capacity (FVC) in patients treated with nintedanib and placebo, respectively, were -78.9 and -187.6 mL/year in patients who received statins at baseline, and -127.9 and -237.9 mL/year in patients who did not. The effect of nintedanib was consistent across subgroups (p = 0.9590). CONCLUSIONS: In the INPULSIS® trials, there was a numerically lower FVC decline in placebo-treated patients with IPF who received statins at baseline versus those who did not. Use of statins at baseline did not influence the treatment effect of nintedanib. Prospective data are needed to assess the impact of statins on the course of IPF.

Neurofeedback of Slow Cortical Potentials in Children with Attention-Deficit/Hyperactivity Disorder: A Multicenter Randomized Trial Controlling for Unspecific Effects.

Background: Neurofeedback (NF) in children with attention-deficit/hyperactivity disorder (ADHD) has been investigated in a series of studies over the last years. Previous studies did not unanimously support NF as a treatment in ADHD. Most studies did not control for unspecific treatment effects and did not demonstrate that self-regulation took place. The present study examined the efficacy of NF in comparison to electromyographic (EMG) feedback to control for unspecific effects of the treatment, and assessed self-regulation of slow cortical potentials (SCPs). Methods: A total of 150 children aged 7-9 years diagnosed with ADHD (82% male; 43% medicated) were randomized to 25 sessions of feedback of SCPs (NF) or feedback of coordination of the supraspinatus muscles (EMG). The primary endpoint was the change in parents' ratings of ADHD core symptoms 4 weeks after the end of treatment compared to pre-tests. Results: Children in both groups showed reduced ADHD-core symptoms (NF 0.3, 95% CI -0.42 to -0.18; EMG 0.13, 95% CI -0.26 to -0.01). NF showed a significant superiority over EMG (treatment difference 0.17, 95% CI 0.02-0.3, p = 0.02). This yielded an effect size (ES) of d = 0.57 without and 0.40 with baseline observation carried forward (BOCF). The sensitivity analysis confirmed the primary result. Successful self-regulation of brain activity was observed only in NF. As a secondary result teachers reported no superior improvement from NF compared to EMG, but within-group analysis revealed effects of NF on the global ADHD score, inattention, and impulsivity. In contrast, EMG feedback did not result in changes despite more pronounced self-regulation learning. Conclusions: Based on the primary parent-rated outcome NF proved to be superior to a semi-active EMG feedback treatment. The study supports the feasibility and efficacy of NF in a large sample of children with ADHD, based on both specific and unspecific effects. Trial Register: Current controlled trials ISRCTN76187185, registered 5 February 2009.

Randomized controlled study of early medication change for non-improvers to antidepressant therapy in major depression--The EMC trial.

Patients with Major Depressive Disorder (MDD) and no improvement after two weeks of antidepressant pharmacotherapy have a high risk of treatment failure. The aim of the study was to determine whether an early medication change (EMC) strategy is superior to a guideline-based treatment in MDD patients without improvement after two weeks of antidepressant pharmacotherapy. Eight-hundred-and-eighty-nine patients with MDD were enrolled, 879 patients received the SSRI escitalopram. Of those, 192 patients had no improvement, defined as a reduction of < 20% on the Hamilton Depression Rating Scale (HAMD-17) after 14 days of treatment, and were randomly assigned to open treatment with the EMC strategy (n = 97; venlafaxine XR for study days 15-56; in case of sustained non-improvement on day 28, lithium augmentation for days 29-56) or TAU (n = 95; escitalopram continuation; non-responders on day 28 were switched to venlafaxine XR for four weeks, i.e. days 29-56). The primary outcome was remission (HAMD-17 ≤ 7) after 8 weeks of treatment as assessed by blinded raters. Remission rates were 24% for EMC and 16% for TAU, which was not significantly different (p = 0.2056). Sensitivity analyses for the primary and secondary effectiveness endpoints consistently showed favorable results for patients randomized to EMC. The results confirm data from post-hoc analyses of clinical trials showing that early non-improvement identifies patients who likely need alternate interventions. However, the herein used two-step switch/augmentation strategy for this risk group was not more effective than the control intervention. Alternate strategies and other design aspects are discussed in order to support researchers addressing the same research question.

Rationale and design of the RE-LATED AF--AFNET 7 trial: REsolution of Left atrial-Appendage Thrombus--Effects of Dabigatran in patients with Atrial Fibrillation.

BACKGROUND: Dabigatran etexilate, a direct thrombin inhibitor and non-vitamin K antagonist oral anticoagulant (NOAC), has been shown to effectively prevent thromboembolic events in patients with non-valvular atrial fibrillation (AF). However, there is a paucity of data on the antithrombotic efficacy and safety of dabigatran in the resolution of left atrial appendage (LAA) thrombi in AF patients. OBJECTIVE: The primary objective of the RE-LATED AF trial is to assess whether dabigatran results in a faster complete LAA thrombus resolution as compared to vitamin K antagonist phenprocoumon. Secondary objectives are to assess the impact of dabigatran on complete LAA thrombus resolution rate within 6 weeks of treatment and change in LAA thrombus volume under treatment. Furthermore, this study aims to assess and compare safety and tolerability of dabigatran vs. phenprocoumon. METHODS: The study is designed as a prospective, randomized, open-label, controlled, explorative, blinded endpoint (PROBE) trial. Patients with AF and left atrial appendage thrombus confirmed by transoesophageal echocardiography (TEE) will be randomized to receive either dabigatran (150 mg bid) or phenprocoumon (INR 2-3) for the resolution of LAA thrombus formation for at least 21 days. Thrombus resolution will be determined by TEE 3 weeks after treatment initiation and subsequently at weeks 4 and 6, if the LAA thrombus has not been resolved before. A total of 110 patients are planned to be randomized. CONCLUSION: This is the first prospective, multicentre, randomized controlled clinical trial investigating safety and efficacy of a NOAC for the resolution of LAA thrombi in patients with non-valvular AF.

A comparison of intervention and conservative treatment for angulated fractures of the distal forearm in children (AFIC): study protocol for a randomized controlled trial.

BACKGROUND: Angulated fractures of the distal forearm are very frequent lesions in childhood. Currently, there are no standard guidelines on whether these children should be treated conservatively with a cast; with reduction and a cast; or with reduction, pinning and a cast under anesthesia. Minor prospective and retrospective studies have shown that the distal physis of the forearm possesses high remodeling capacity leading to reliable correction of malalignment. The aim of this trial is to answer the question about whether operative and conservative treatment show equivocal results. METHODS/DESIGN: This is a prospective, multinational, multicenter, randomized, observer-blinded, actively controlled, parallel group trial, with 24 months of observation. The primary objective of this trial is to assess whether or not the long-term functional outcome in remodeling patients is inferior to patients receiving closed reduction and K-wire pinning. The trial should include 742 patients with acute fracture. The patients will be included in 30 medical centers in Germany, Switzerland and Austria. All patients 5 to 11 years of age presenting at the emergency department with an angulated distal fracture of the forearm will be randomized online after informed consent. The primary endpoint is the Cooney Score after 24 months. The secondary endpoint is the grade of radiological displacement at 12/24 months. DISCUSSION: Therapy of angulated fractures is a matter of intensive debate. Primary manipulation and pinning under general anesthesia is recommended in order to avoid malalignment. No major study has proven the advantage of manipulation and pinning over immobilization alone. Should remodeling appear to be a safe alternative, manipulation under general anesthesia, K-wire pinning and removal of pins could be avoided, thus sparing significant costs. TRIAL REGISTRATION: DRKS00004874 , 30 October 2013.

Neurofeedback in children with attention-deficit/hyperactivity disorder (ADHD)--a controlled multicenter study of a non-pharmacological treatment approach.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral disorder of childhood and has often a chronic course persisting into adulthood. However, up to 30% of children treated with stimulants either fail to show an improvement or suffer adverse side effects, including decreased appetite, insomnia and irritability and there is no evidence of long term efficacy of stimulants for ADHD. A series of studies has shown that neurofeedback is an effective additional or alternative treatment for children with ADHD, leading to e.g. significant and stable improvement in behavior, attention and IQ. Significant treatment effects of neurofeedback have also been verified in meta-analyses. Most of the trials, however, have been criticized for methodological difficulties, particularly lacking appropriate control conditions and number of patients included. This randomized study examines the efficacy of slow cortical potentials (SCP) -neurofeedback, controlling unspecific effects of the setting by comparing two active treatment modalities. METHODS/DESIGN: A total of 144 patients with ADHD, older than six and younger than ten years, in some cases with additional pharmacological treatment, are included in this trial. In five trial centres patients are treated either with SCP-feedback or electromyographic (EMG) -feedback in 25 sessions within 3 months. A comprehensive test battery is conducted before and after treatment and at follow-up 6 month later, to assess core symptoms of ADHD, general psychopathology, attentional performance, comorbid symptoms, intelligence, quality of life and cortical arousal. DISCUSSION: The efficacy of SCP-feedback training for children with ADHD is evaluated in this randomized controlled study. In addition to behavior ratings and psychometric tests neurophysiological parameters serve as dependent variables. Further, the choice of EMG-biofeedback as an active control condition is debated. TRIALS REGISTRATION: Current Controlled Trials ISRCTN76187185. Registered 5 February 2009.

CERAMENT treatment of fracture defects (CERTiFy): protocol for a prospective, multicenter, randomized study investigating the use of CERAMENT™ BONE VOID FILLER in tibial plateau fractures.

BACKGROUND: Bone graft substitutes are widely used for reconstruction of posttraumatic bone defects. However, their clinical significance in comparison to autologous bone grafting, the gold-standard in reconstruction of larger bone defects, still remains under debate. This prospective, randomized, controlled clinical study investigates the differences in pain, quality of life, and cost of care in the treatment of tibia plateau fractures-associated bone defects using either autologous bone grafting or bioresorbable hydroxyapatite/calcium sulphate cement (CERAMENT™|BONE VOID FILLER (CBVF)). METHODS/DESIGN: CERTiFy (CERament™ Treatment of Fracture defects) is a prospective, multicenter, controlled, randomized trial. We plan to enroll 136 patients with fresh traumatic depression fractures of the proximal tibia (types AO 41-B2 and AO 41-B3) in 13 participating centers in Germany. Patients will be randomized to receive either autologous iliac crest bone graft or CBVF after reduction and osteosynthesis of the fracture to reconstruct the subchondral bone defect and prevent the subsidence of the articular surface. The primary outcome is the SF-12 Physical Component Summary at week 26. The co-primary endpoint is the pain level 26 weeks after surgery measured by a visual analog scale. The SF-12 Mental Component Summary after 26 weeks and costs of care will serve as key secondary endpoints. The study is designed to show non-inferiority of the CBVF treatment to the autologous iliac crest bone graft with respect to the physical component of quality of life. The pain level at 26 weeks after surgery is expected to be lower in the CERAMENT bone void filler treatment group. DISCUSSION: CERTiFy is the first randomized multicenter clinical trial designed to compare quality of life, pain, and cost of care in the use of the CBVF and the autologous iliac crest bone graft in the treatment of tibia plateau fractures. The results are expected to influence future treatment recommendations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT01828905.

Blinded Sample Size Recalculation in Longitudinal Clinical Trials Using Generalized Estimating Equations.

In clinical trials in which outcomes are measured repeatedly during the follow-up phase, data analysis is frequently performed using generalized estimating equations (GEEs). Sample size calculation is then especially challenging since in addition to the treatment effect, the intrasubject correlation and the variability of the model error term have to be specified. In this article, the authors investigated by Monte Carlo simulations whether a blinded midcourse estimation of these quantities in an internal pilot study design is feasible in such trials and whether nominal type I and type II error rates are preserved when the estimates are used for sample size recalculation. The actual type I error rates of the blinded sample size recalculation procedure turned out to agree well with the nominal levels. Furthermore, the simulated power was observed to be near the target value as long as the sample size of the internal pilot study was sufficiently high and the bound effects induced by the range of the correlation were limited. The proposed procedure is a helpful tool to achieve robustness of the power with respect to initial misspecifications in the planning stage in clinical trials analyzed by GEE.

No beneficial effect of all-trans retinoic acid in previous non-responder patients with chronic hepatitis C: the ATRACTION study, a phase II randomised trial.

BACKGROUND: Preclinical data suggested all-trans retinoic acid (tretinoin) as a potential antiviral agent against chronic hepatitis C infection. AIMS: To assess efficacy, safety, and tolerability of tretinoin in combination with peg-interferon and ribavirin in genotype-1 infected patients with prior non-response. METHOD: We performed an open-label multicentre clinical trial. Patients were randomised to either receive additional tretinoin (45mg/m(2)/day) for 12 weeks (arm A), or peg-interferon and ribavirin alone (arm B). Primary endpoint was the slope of the third phase of viral decline (Mδ) as determined in an established kinetic model known to correlate with treatment outcome. Secondary endpoints were additional kinetic parameters, viral response rates, safety, and tolerability. RESULTS: 27 patients in arm A and 30 patients in arm B were treated per protocol until week 12. Viral kinetic parameters did not differ. Rates of early virological response (>2log10 drop at week 12) were similar (10/27 versus 11/30 patients). In arm A, patients experienced a higher rate and intensity of adverse events, most commonly skin and mucosal dryness, and headache. CONCLUSION: Addition of tretinoin was safe and acceptably well tolerated. However, it did not influence viral kinetics and thus cannot be further considered as a treatment option.

Necessity of 3D visualization for the removal of lower wisdom teeth: required sample size to prove non-inferiority of panoramic radiography compared to CBCT.

The availability of cone beam computed tomography (CBCT) and the numbers of CBCT scans rise constantly, increasing the radiation burden to the patient. A growing discussion is noticeable if a CBCT scan prior to the surgical removal of wisdom teeth may be indicated. We aimed to confirm non-inferiority with respect to damage of the inferior alveolar nerve in patients diagnosed by panoramic radiography compared to CBCT in a prospective randomized controlled multicentre trial. Sample size (number of required third molar removals) was calculated for the study and control groups as 183,474 comparing temporary and 649,036 comparing permanent neurosensory disturbances of the inferior alveolar nerve. Modifying parameter values resulted in sample sizes ranging from 39,584 to 245,724 respectively 140,024 to 869,250. To conduct a clinical study to prove a potential benefit from CBCT scans prior to surgical removal of lower wisdom teeth with respect to the most important parameter, i.e., nerval damage, is almost impossible due to the very large sample sizes required. This fact vice versa indicates that CBCT scans should only be performed in high risk wisdom tooth removals.

Sample size calculation in clinical trials: part 13 of a series on evaluation of scientific publications.

BACKGROUND: In this article, we discuss the purpose of sample size calculation in clinical trials, the need for it, and the methods by which it is accomplished. Study samples that are either too small or too large are unacceptable, for clinical, methodological, and ethical reasons. The physicians participating in clinical trials should be directly involved in sample size planning, because their expertise and knowledge of the literature are indispensable. METHODS: We explain the process of sample size calculation on the basis of articles retrieved by a selective search of the international literature, as well as our own experience. RESULTS: We present a fictitious clinical trial in which two antihypertensive agents are to be compared to each other with a t-test and then show how the appropriate size of the study sample should be calculated. Next, we describe the general principles of sample size calculation that apply when any kind of statistical test is to be used. We give further illustrative examples and explain what types of expert medical knowledge and assumptions are needed to calculate the appropriate sample size for each. These generally depend on the particular statistical test that is to be performed. CONCLUSION: In any clinical trial, the sample size has to be planned on a justifiable, rational basis. The purpose of sample size calculation is to determine the optimal number of participants (patients) to be included in the trial. Sample size calculation requires the collaboration of experienced biostatisticians and physician-researchers: expert medical knowledge is an essential part of it.

Rationale and design of the randomised clinical trial comparing early medication change (EMC) strategy with treatment as usual (TAU) in patients with major depressive disorder--the EMC trial.

BACKGROUND: In major depressive disorder (MDD), the traditional belief of a delayed onset of antidepressants' effects has lead to the concept of current guidelines that treatment durations should be between 3-8 weeks before medication change in case of insufficient outcome. Post hoc analyses of clinical trials, however, have shown that improvement usually occurs within the first 10-14 days of treatment and that such early improvement (Hamilton Depression Rating Scale [HAMD] decrease >or=20%) has a substantial predictive value for final treatment outcome. Even more important, non-improvement (HAMD decrease <20%) after 14 days of treatment was found to be highly predictive for a poor final treatment outcome. METHODS/DESIGN: The EMC trial is a phase IV, multi-centre, multi-step, randomized, observer-blinded, actively controlled parallel-group clinical trial to investigate for the first time prospectively, whether non-improvers after 14 days of antidepressant treatment with an early medication change (EMC) are more likely to attain remission (HAMD-17

Effects of pentaerythritol tetranitrate on endothelial function in coronary artery disease: results of the PENTA study.

BACKGROUND: Pentaerythritol tetranitrate (PETN) differs from other organic nitrates by the lack of tolerance induction and by antioxidative properties. The purpose of this study was to determine the effect of PETN on endothelial function in patients with coronary artery disease (CAD). We hypothesized that the treatment with PETN improves endothelial function in patients with CAD. METHODS: In a prospective, double-blind study, we randomly assigned 80 patients to treatment for 8 weeks with oral PETN 80 mg t.i.d. (PETN) or placebo (C). The primary endpoint was the absolute change in brachial artery flow-mediated dilation (FMD) from baseline to follow-up. Furthermore, changes in nitroglycerin-mediated dilation (NMD), digital peripheral arterial tonometry (PAT) index, vascular shear stress, mean flow velocity, plasma bilirubin, C-reactive protein (CRP) and thiobarbituric acid reactive substances (TBARS), serum ferritin, and the activity of the PETN bioactivating enzyme aldehyde dehydrogenase-2 (ALDH-2) in peripheral blood mononuclear cells were analyzed. Raw data entry, data monitoring and statistical analysis were performed independently. RESULTS: The treatment groups were comparable regarding demographics, cardiovascular risk and concomitant medication. There was no difference in the change in FMD between the two treatment groups (mean +/- SD: PETN: +1.6 +/- 3.3% vs. C: +1.4 +/- 4.1%; P = 0.7). NMD increased after treatment with PETN and was higher compared with C (PETN: +3.8 +/- 5.5% vs. C: +0.6 +/- 4.2%; P = 0.004). Mean PAT index and ALDH-2 activity remained unchanged. Relative changes in mean flow volume (P = 0.04) and mean flow velocity (P = 0.01) upon ischemia increased in the PETN group versus C. Changes in bilirubin, ferritin, TBARS and CRP did not differ between the groups. CONCLUSIONS: We conclude that chronic PETN therapy in patients with CAD may be established for symptomatic treatment without adverse effects on endothelial function and with beneficial effects on the microcirculation.

Types of study in medical research: part 3 of a series on evaluation of scientific publications.

BACKGROUND: The choice of study type is an important aspect of the design of medical studies. The study design and consequent study type are major determinants of a study's scientific quality and clinical value. METHODS: This article describes the structured classification of studies into two types, primary and secondary, as well as a further subclassification of studies of primary type. This is done on the basis of a selective literature search concerning study types in medical research, in addition to the authors' own experience. RESULTS: Three main areas of medical research can be distinguished by study type: basic (experimental), clinical, and epidemiological research. Furthermore, clinical and epidemiological studies can be further subclassified as either interventional or noninterventional. CONCLUSIONS: The study type that can best answer the particular research question at hand must be determined not only on a purely scientific basis, but also in view of the available financial resources, staffing, and practical feasibility (organization, medical prerequisites, number of patients, etc.).

Neoadjuvant chemoradiation and local excision for T2-3 rectal cancer.

BACKGROUND: Local excision (LE) of T1 low-risk (G1-2/L0/V0) rectal cancer is an established approach with local recurrence (LR) rates of approximately 5%, whereas LE of > or = T2 high-risk tumors or inadequate resections (R1/RX/R < or = 1 mm) showed high recurrence rates. Because of the favorable results after neoadjuvant chemoradiotherapy (nCRT) and radical surgery of disease that completely responds (CR) with almost absent LR even of T3-4 tumors, an extension of the indication for LE is controversially discussed, and therefore, we assessed this therapeutic option. METHODS: Including our own data, seven studies about LE after nCRT of cT2-3 tumors (n = 237) were analyzed after a PubMed search for cT categories, tumor height, nCRT regimens, schedule and technique of surgery, complications, freedom of stoma, response rates (ypT0-3), length of follow-up, LR, and metastases. RESULTS: Subgroups that we formed (retrospective vs. prospective/retractor vs. transanal endoscopic microsurgery) showed differences in the distribution of cT categories. However, neither the studies we considered nor our own patients showed LR in CR (ypT0). In addition, patients with ypT1 tumor consistently showed low LR rates of 2% (range, 0%-6%), whereas in ypT2 findings, less favorable LR rates of 6% to 20% were observed, and disease that did not respond to therapy (ypT3) displayed LR rates in up to 42%. CONCLUSIONS: Despite of a highly selected patient collective, an extended indication for LE of cT2-3 rectal cancer after nCRT may be considered. The strongest prognostic factors were a CR (ypT0) or responses on submucosa level (ypT1). These first results will have to be confirmed in a prospective trial with an appropriate sample size to ensure high statistical power.