Objective: Medical decision-making is often uncertain. The positive predictive value (PPV) and negative predictive value (NPV) are conditional probabilities characterizing diagnostic tests and assessing diagnostic interventions in clinical medicine and epidemiology. The PPV is the probability that a patient has a specified disease, given a positive test result for that disease. The NPV is the probability that a patient does not have the disease, given a negative test result for that disease. Both values depend on disease incidence or prevalence, which may be highly uncertain for unfamiliar diseases, epidemics, etc. Probability distributions for this uncertainty are usually unavailable. We develop a non-probabilistic method for interpreting PPV and NPV with uncertain prevalence.
Methods: Uncertainty in PPV and NPV is managed with the non-probabilistic concept of robustness in info-gap theory. Robustness of PPV or NPV estimates is the greatest uncertainty (in prevalence) at which the estimate’s error is acceptable.
Results: Four properties are demonstrated. Zeroing: best estimates of PPV or NPV have no robustness to uncertain prevalence; best estimates are unreliable for interpreting diagnostic tests. Trade-off: robustness increases as error increases; this trade-off identifies robustly reliable error in PPV or NPV. Preference reversal: sometimes sub-optimal PPV or NPV estimates are more robust to uncertain incidence or prevalence than optimal estimates, motivating reversal of preference from the putative optimum to the sub-optimal estimate. Trade-off between specificity and robustness to uncertainty: the robustness increases as test-specificity decreases. These four properties underlie the interpretation of PPV and NPV.
Conclusions: The PPV and NPV assess diagnostic tests, but are sensitive to lack of knowledge that generates non-probabilistic uncertain prevalence and must be supplemented with robustness analysis. When uncertainties abound, as with unfamiliar diseases, assessing robustness is critical to avoiding erroneous decisions.
Pancytopenia is defined as a reduction in red blood cells, white blood cells, and platelets, and can pose as a diagnostic challenge due to the multitude of causes. Myxedema coma is the manifestation of severe untreated hypothyroidism. This case report presents a rare instance of myxedema coma-associated pancytopenia in a 53-year-old man with a history of untreated hypothyroidism. The patient presented with altered mental status and vital instability, and on further workup was found to have pancytopenia. During his hospital stay his symptomatic hypothyroidism was identified, and he was treated with intravenous levothyroxine, hydrocortisone, and supportive care. The patient’s clinical status improved gradually, with normalized blood counts upon discharge. This case underscores the significance of considering myxedema coma in the differential diagnosis of pancytopenia, especially in older patients with limited healthcare access. Increased awareness of this association can aid clinicians in timely diagnosis and management, preventing potential complications associated with untreated hypothyroidism.
Public health is connected to cannabis with regard to food, animal feed (feed), and pharmaceuticals. There¬fore, the use of phytocannabinoids should be examined from a One Health perspective. Current knowledge on medical cannabis treatment (MCT) does not address sufficiently diseases which are of epidemiological and of zoonotic concern. The use of cannabinoids in veterinary medicine is illegal in most countries, mostly due to lack of evidence-based medicine. To answer the growing need of scientific evidence-based applicable medicine in both human and veterinary medicine, a new approach for the investigation of the therapeutic potential of cannabinoids must be adopted. A model that offers direct study of a specific disease in human and veterinary patients may facilitate development of novel therapies. Therefore, we urge the regulatory authorities—the ministries of health and agriculture (in Israel and worldwide)—to publish guidelines for veterinary use due to its importance to public health, as well as to promote One Health-related preclinical translational medicine studies for the general public health.
Good morning. It is a great pleasure to share my thoughts with you here in Israel. The last day I was here was June 25, 2016, which was the day of the results of the Brexit referendum. My wife and I escaped feeling so depressed, but at least, we thought, we are leaving this behind; but when we came to Israel the only thing people wanted to talk about was the Brexit referendum!
Here I am today, on October 31, 2019, the day that we were meant to be leaving the European Union, so there is something with my connection with Israel and Brexit that I don’t understand! Let me start by saying that we have the privilege of being participants in a biomedical and health science revolution. I don’t think that is overstating it. We are living in an extraordinary, exciting time. Let me remind you of some of these fields that are moving so fast.
Beyond the increase in medical knowledge and biotechnology during the last decades, doctors have adopted professional norms that would have been considered heretical only two generations ago. The changes transpired between the 1970s and 1990s, and generated controversies between those who upheld the traditional values of patient care, and those who welcomed the new professional norms. Professor Dr Johannes Juda Groen (1903–1990) predicted and promoted some of these changes. As early as the 1940s through the 1960s, he recognized the need to teach interviewing skills and advocated an orientation to patients, rather than to diseases; he supported decision-making based on evidence, rather than on personal experience and pathophysiologic rationale; and he demonstrated that psychosocial determinants predict, rather than only correlate with, disease. These views led to confrontations with the medical establishments in the Netherlands and in Israel. Still, many of his colleagues recognized the value of his contributions. The author, for one, admires Groen’s commitment in challenging the prevailing clinical wisdom after the end of World War 2, and his courage in opposing the views of his colleagues.
Background: Crimean–Congo hemorrhagic fever (CCHF) is a tick-borne viral disease with a high mortality rate. Although CCHF has been widely investigated over the past decade, a review of the literature indicated no data on the prognostic capacity of the mean platelet volume-to-platelet count ratio (MPVPCR) and the red cell distribution width-to-platelet count ratio (RDWPCR) for the systemic inflammatory response in patients with CCHF. This study aimed to evaluate the prognostic ability of MPVPCR and RDWPCR on mortality in patients with CCHF.
Methods: A total of 807 patients that were admitted to the Cumhuriyet University Hospital’s Emergency Department from January 2010 to December 2018 were involved. The RDWPCR and MPVPCR were separately calculated via absolute blood red cell and platelet counts at the time of admission. Before performing receiver-operating characteristic (ROC) curve analysis to define the optimum cut-off values of MPVPCR and RDWPCR stepwise logistic regression analysis was used to determine the predictive factors related to mortality in CCHF patients.
Results: Values of both MPVPCR and RDWPCR were significantly lower in survivors than in non-survivors (MPVPCR: 0.20±0.23 versus 0.55±0.55, P<0.001; RDWPCR: 0.27±0.32 versus 0.77±0.77, P<0.001, respectively). The MPVPCR (odds ratio [OR], 5.95; P=0.048) was an independent predictor for the prognosis of mortality in CCHF patients. The area under the curve in the ROC curve analysis for MPVPCR was 0.876 with a cut-off of 0.21 (sensitivity 87%, specificity 76%).
Conclusion: At the time of admission, MPVPCR might be a useful predictor of mortality in patients with CCHF.
Chronic pain is a common complaint among patients, and rheumatic diseases are a common cause for chronic pain. Current pharmacological interventions for chronic pain are not always useful or safe enough for long-term use. Cannabis and cannabinoids are currently being studied due to their potential as analgesics. In this review we will discuss current literature regarding cannabinoids and cannabis as treatment for rheumatic diseases. Fibromyalgia is a prevalent rheumatic disease that causes diffuse pain, fatigue, and sleep disturbances. Treatment of this syndrome is symptomatic, and it has been suggested that cannabis and cannabinoids could potentially alleviate some of the symptoms associated with fibromyalgia. In this review we cite some of the evidence that supports this claim. However, data on long-term efficacy and safety of cannabinoid and cannabis use are still lacking. Cannabinoids and cannabis are commonly investigated as analgesic agents, but in recent years more evidence has accumulated on their potential immune-modulatory effect, supported by results in animal models of certain rheumatic diseases. While results that demonstrate the same effect in humans are still lacking, cannabinoids and cannabis remain potential drugs to alleviate the pain associated with rheumatic diseases, as they were shown to be safe and to cause limited adverse effects.
The use of medical cannabis in children is rapidly growing. While robust evidence currently exists only for pure cannabidiol (CBD) to treat specific types of refractory epilepsy, in most cases, artisanal strains of CBD-rich medical cannabis are being used to treat children with various types of refractory epilepsy or irritability associated with autism spectrum disorder (ASD). Other common pediatric disorders that are being considered for cannabis treatment are Tourette syndrome and spasticity. As recreational cannabis use during youth is associated with serious adverse events and medical cannabis use is believed to have a relatively high placebo effect, decisions to use medical cannabis during childhood and adolescence should be made with caution and based on evidence. This review summarizes the current evidence for safety, tolerability, and efficacy of medical cannabis in children with epilepsy and in children with ASD. The main risks associated with use of Δ9-tetrahydrocannabinol (THC) and CBD in the pediatric population are described, as well as the debate regarding the use of whole-plant extract to retain a possible “entourage effect” as opposed to pure cannabinoids that are more standardized and reproducible.
Cannabis is the most widely used recreational drug worldwide and is used by some patients with inflam-matory bowel disease (IBD) to ameliorate their disease. Whereas epidemiological studies indicate that as many as 15% of IBD patients use cannabis, studies inspecting cannabis use in IBD are few and small. We have conducted several studies looking at the use of cannabis in IBD. In Crohn’s disease, we demonstrated that cannabis reduces the Crohn’s disease activity index (CDAI) by >100 points (on a scale from 0-450).Two small studies in ulcerative colitis showed a marginal benefit. However, no improvement was observed in inflammatory markers or in endoscopic score in either disease. Many questions regarding cannabis use in IBD remain unanswered. For example, cannabis is a complex plant containing many ingredients, and the synergism or antagonism between them likely plays a role in the relative efficacy of various cannabis strains. The optimal doses and mode of consumption are not determined, and the most common form of consump¬tion, i.e. smoking, is unacceptable for delivering medical treatment. Cannabis is a psychotropic drug, and the consequences of long-term use are unknown. Despite all these limitations, public opinion regards cannabis as a harmless drug with substantial medical efficacy. In Israel, the number of licenses issued for the medical use of cannabis is rising rapidly, as are the acknowledged indications for such use, but good-quality evidence for the effectiveness of cannabis is still lacking. Further studies investigating the medical use of cannabis are urgently needed.
In the last decade, we have observed an increased public and scientific interest in the clinical applications of medical cannabis. Currently, the application of cannabinoids in cancer patients is mainly due to their analgesic and anti-emetic effects. The direct effects of phyto-cannabinoids on cancer cells are under intensive research, and the data remain somewhat inconsistent. Although anti-proliferative properties were observed in vitro, conclusive data from animal models and clinical trials are lacking. Since immunotherapy of malignant diseases and bone marrow transplantation are integral approaches in hemato-oncology, the immuno-modulatory characteristic of cannabinoids is a fundamental aspect for consideration. The effect of cannabinoids on the immune system is presently under investigation, and some evidence for its immuno-regulatory properties has been shown. In addition, the interaction of cannabinoids and classical cytotoxic agents is a subject for further investigation. Here we discuss the current knowledge of cannabinoid-based treatments in preclinical models and the limited data in oncological patients. Particularly, we address the possible contradiction between the direct anti-tumor and the immune-modulatory effects of cannabinoids. Better understanding of the mechanism of cannabinoids influence is essential to design therapies that will allow cannabinoids to be incorporated into the clinic.
