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Randomized double-blind placebo-controlled trials (RCTs) are regarded as the gold standard for clinical trials. While there are established standards to avoid unblinding, in RCTs using tetrahydrocannabinol (THC) containing cannabinoids, however, accidental unblinding and intentional self-unbinding must be considered as a particular issue, since THC tests are widely available. To investigate unblinding rates in an RCT using a THC-containing cannabinoid, we re-contacted 54 out of 97 participants of the CANNA-TICS trial who had participated in our study center in Hannover. Of the 54 participants, 53 could be reached. Of these, one participant (2%) stated that she had unblinded herself intentionally during the treatment phase, and another three patients (6%) reported intentional unblinding after the end of the treatment. Noteworthy, two patients provided discrepant information and denied self-unblinding during the interview, although during study/clinic visits they had reported having done so. Thus, based on all available information, three participants (6%) unblinded themselves intentionally during the treatment phase and another three (6%) after the end of the treatment. Accidental unblinding during the treatment phase was reported by 4/54 participants (7%) (during study visits). Since one participant reported both intentional self-unblinding (during the interview) and accidental unblinding (during a study visit), the total unblinding rate was 17% (n = 9). Of these, seven participants (13%) reported unblinding during the treatment phase. When asked in the interview whether they knew that self-unblinding would have been possible, only 34% (n = 18/53) of participants stated that they had been aware of this possibility. Thus, altogether 33% (n = 6/18) of those being informed about the possibility of self-unblinding did so and half of them (3/18, 17 %) during the treatment phase. It can be expected that in parallel to increasing knowledge of medicinal and recreational use of cannabinoids, more and more people will also be informed about the availability of THC tests. Hence, in future RCTs using THC-containing cannabinoids, researchers have to take the possibility of accidental and intentional unblinding into consideration, when designing the study.

Background: Readers of clinical trial reports should be able to critically evaluate the design, results, and conclusions of the trial. There are internationally accepted guidelines that define methodological standards for trial planning, statistical methods, and the display and interpretation of the results. Publications may nonetheless contain erroneous findings and interpretations. Methods: Statistical errors can arise in the planning of the trial, the analysis and display of the results, as well as in the interpretation of p-values and treatment effects in experimental and observational clinical trials. A useful aid for readers of medical publications should include a description of the potential statistical problems without complex theoretical background information. With this aim, we discuss certain major types of statistical error that the reader should be familiar with in order to be able to interpret the conclusions of these publications more easily. Results: Statistical errors can already arise at an early stage through the choice of the wrong question to be addressed or the wrong population to be analyzed; such errors will inevitably have consequences. Before the start of any clinical trial, a primary endpoint must be defined, the sample size must be calculated, and the trial must be appropriately registered (among other requirements). With regard to the analysis, readers should for example take into account whether a statistical analysis plan with an intention-to-treat analysis existed for the study in question. They must be able to recognize erroneous methods of displaying and comparing data, confounding, as well as incorrect interpretations of p-values, and should take these problems into account when interpreting the findings. The problem of invalid causal inferences is not restricted to observational studies. Conclusions: Statistical errors do, indeed, arise. They should be detected as early as possible in various test instances. Nonetheless, readers should be able to judge independently whether the published clinical trial reflects meticulous and correct trial planning, appropriate display of the trial's results, and a proper, reasoned interpretation of the findings. The published checklists are a good aid for this purpose. [ABSTRACT FROM AUTHOR]

Introduction: Antibiotic resistance is a serious threat to global public health. It reduces the effectiveness of treatments for serious bacterial infections and thus increases the risk of fatal outcomes. Antibiotic prescriptions are often not in line with clinical evidence-based guidelines. The process of emergence of resistant bacteria can be slowed down by adherence to guidelines. Yet this adherence seems to be lacking in primary health care.Methods and Analysis: This pragmatic quasi-experimental study using a controlled before-after design was carried out in South-East-Lower Saxony in 2018–2020. The voluntary attendance of interactive trainings with condensed presentation of current guidelines for general practitioners (GP) on antibiotic management for urinary and respiratory tract infections is regarded as intervention. Those GP not attending the trainings constitute the control group. Data were collected via questionnaires; routine health records are provided by a statutory health insurance. The primary outcome is the proportion of (guideline-based) prescriptions in relation to the relevant ICD-10 codes as well as daily defined doses and the difference in proportion of certain prescriptions according to guidelines before and after the intervention as compared to the control group. Further outcomes are among others the subjectively perceived risk of antibiotic resistance and the attitude toward the guidelines. The questionnaires to assess this are based on theory of planned behavior (TPB) and health action process approach (HAPA). Variations over time and effects caused by measures other than WASA (Wirksamkeit von Antibiotika-Schulungen in der niedergelassenen Aerzteschaft-Effectiveness of antibiotic management training in the primary health care sector) training are taken into account by including the control group and applying interrupted time series analysis.Ethics and Dissemination: The study protocol and the data protection concept respectively were reviewed and approved by the Ethics Committee of the Hannover Medical School and the Federal Commissioner for Data Protection and Freedom of Information.Trial Registration:https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00013951, identifier DRKS00013951.

Abstract Background Nonspecific acute low back pain (LBP) is a common reason for accessing primary care. German guidelines recommend non-steroidal anti-inflammatory drugs and physical activity as evidence-based treatments. Manual Therapy (MT) remains controversial. To increase evidence-based treatment options for general practitioners (GPs), a Pilot-Study was set up to gather information about the required conditions and setting for an RCT. Methods The open pilot-study assesses recruitment methods for GPs and patients, timelines, data collection and outcomes of treatment immediately (T0) and 1, 6 and 12 weeks after consultation (T1, T2, T3). Inclusion criteria for GPs were: no experience of MT; for patients: adults between 18 and 50 suffering from LBP for less than 14 days. Study process: Patients’ control-group (CG) was consecutively recruited first and received standard care. After GPs received a single training session in MT lasting two and a half hours, they consecutively recruited patients with LBP to the intervention group (IG). These patients received add-on MT. Primary outcomes: (A): timelines and recruitment success, (B): assessment tools and sample size evaluation, (C) clinical findings: pain intensity change from baseline to day 3 and time till (a) analgesic use stopped and (b) 2-point pain reduction on an 11-point scale occurred. Secondary outcomes: functional capacity, referral rate, use of other therapies, sick leave, patient satisfaction. Results 14 GPs participated, recruiting 42 patients for the CG and 45 for the IG; 49% (56%) of patients were women. Average baseline pain was 5.98 points, SD: ±2.3 (5.98, SD ±1.8). For an RCT an extended timeline and enhanced recruitment procedures are required. The assessment tools seem appropriate and provided relevant findings: additional MT led to faster pain reduction. IG showed reduced analgesic use and reduced pain at T1 and improved functional capacity by T2. Conclusions Before verifying the encouraging findings that additional MT may lead to faster pain reduction and reduced analgesic use via an RCT, the setting, patients’ structure, and inclusion criteria should be considered more closely. Trial registration Number: DRKS00003240 Registry: German Clinical Trials Registry (DRKS) URL: https://www.drks.de/drks_web/. Registration date: 14.11.2011. First patient: March 2012. Funding: the Rut and Klaus Bahlsen Stiftung, Hannover.

Abstract Background A number of papers have proposed or evaluated the delayed-start design as an alternative to the standard two-arm parallel group randomized clinical trial (RCT) design in the field of rare disease. However the discussion is felt to lack a sufficient degree of consideration devoted to the true virtues of the delayed start design and the implications either in terms of required sample-size, overall information, or interpretation of the estimate in the context of small populations. Objectives To evaluate whether there are real advantages of the delayed-start design particularly in terms of overall efficacy and sample size requirements as a proposed alternative to the standard parallel group RCT in the field of rare disease. Methods We used a real-life example to compare the delayed-start design with the standard RCT in terms of sample size requirements. Then, based on three scenarios regarding the development of the treatment effect over time, the advantages, limitations and potential costs of the delayed-start design are discussed. Results We clarify that delayed-start design is not suitable for drugs that establish an immediate treatment effect, but for drugs with effects developing over time, instead. In addition, the sample size will always increase as an implication for a reduced time on placebo resulting in a decreased treatment effect. Conclusions A number of papers have repeated well-known arguments to justify the delayed-start design as appropriate alternative to the standard parallel group RCT in the field of rare disease and do not discuss the specific needs of research methodology in this field. The main point is that a limited time on placebo will result in an underestimated treatment effect and, in consequence, in larger sample size requirements compared to those expected under a standard parallel-group design. This also impacts on benefit-risk assessment.

The genome of Drosophila melanogaster includes homologs to approximately one-third of the currently known human disease genes. Flies and humans share many biological processes, including the principles of information processing by excitable neurons, synaptic transmission, and the chemical signals involved in intercellular communication. Studies on the molecular and behavioral impact of genetic risk factors of human neuro-developmental disorders [autism spectrum disorders (ASDs), schizophrenia, attention deficit hyperactivity disorders, and Tourette syndrome] increasingly use the well-studied social behavior of D. melanogaster, an organism that is amenable to a large variety of genetic manipulations. Neuroligins (Nlgs) are a family of phylogenetically conserved postsynaptic adhesion molecules present (among others) in nematodes, insects, and mammals. Impaired function of Nlgs (particularly of Nlg 3 and 4) has been associated with ASDs in humans and impaired social and communication behavior in mice. Making use of a set of behavioral and social assays, we, here, analyzed the impact of two Drosophila Nlgs, Dnlg2 and Dnlg4, which are differentially expressed at excitatory and inhibitory central nervous synapses, respectively. Both Nlgs seem to be associated with diurnal activity and social behavior. Even though deficiencies in Dnlg2 and Dnlg4 appeared to have no effects on sensory or motor systems, they differentially impacted on social interactions, suggesting that social behavior is distinctly regulated by these Nlgs.

BackgroundSympathetic and parasympathetic influences on heart rate (HR), which are governed by baroreflex mechanisms, are integrated at the cardiac sinus node through hyperpolarization‐activated cyclic nucleotide–gated channels (HCN4). We hypothesized that HCN4 blockade with ivabradine selectively attenuates HR and baroreflex HR regulation, leaving baroreflex control of muscle sympathetic nerve activity intact. Methods and ResultsWe treated 21 healthy men with 2×7.5 mg ivabradine or placebo in a randomized crossover fashion. We recorded electrocardiogram, blood pressure, and muscle sympathetic nerve activity at rest and during pharmacological baroreflex testing. Ivabradine reduced normalized HR from 65.9±8.1 to 58.4±6.2 beats per minute (P