The number needed to treat (NNT) is a simple measure of a treatment’s impact, increasingly reported in randomized trials and observational studies. It has been found to be incorrectly calculated in several studies involving varying follow-up times. We discuss the NNT in these contexts and illustrate the concept using several published studies. The computation of the NNT is founded on the cumulative incidence of the outcome. Instead, several published studies use simple proportions that do not account for varying follow-up times, or use incidence rates per person-time. We show how these approaches can lead to erroneous values of the NNT and misleading interpretations. For example, a trial of 3,845 very elderly hypertensives randomized to a diuretic or placebo reported a NNT of 94 treated for 2 years to prevent one stroke, though the correct approach results in a NNT of 63. We also note that meta-analyses involve trials of differing lengths, but often report a single NNT. For example a meta-analysis of 22 trials of the anticholinergic tiotropium in chronic obstructive pulmonary disease reported a NNT of 16 patients “over one year,” even if the trials varied in duration from 3 to 48 months, with the more specifically computed NNTs varying widely from 72, 15, and 250 for the 3-month, 12-month, and 48-month trials, respectively. Finally, we describe the value of the NNT in assessing benefit–risk, such as low-dose aspirin use in secondary prevention, where prevention of mortality was assessed against the risk of gastrointestinal bleeding. As the “number needed to treat” becomes increasingly used in the comparative effectiveness and safety of therapies, its accurate estimation and interpretation become crucial to avoid distorting clinical, economic, and public health decisions.
During the past 50 years, a dramatic reduction in the mortality rate associated with cardiovascular disease has occurred in the US and other countries. Statistical modeling has revealed that approximately half of this reduction is the result of risk factor mitigation. The successful identification of such risk factors was pioneered and has continued with the Framingham Heart Study, which began in 1949 as a project of the US National Heart Institute (now part of the National Heart, Lung, and Blood Institute). Decreases in total cholesterol, blood pressure, smoking, and physical inactivity account for 24%, 20%, 12%, and 5% reductions in the mortality rate, respectively. Nephrology was designated as a recognized medical professional specialty a few years later. Hemodialysis was first performed in 1943. The US Medicare End-Stage Renal Disease (ESRD) Program was established in 1972. The number of patients in the program increased from 5,000 in the first year to more than 500,000 in recent years. Only recently have efforts for risk factor identification, early diagnosis, and prevention of chronic kidney disease (CKD) been undertaken. By applying the approach of the Framingham Heart Study to address CKD risk factors, we hope to mirror the success of cardiology; we aim to prevent progression to ESRD and to avoid the cardiovascular complications associated with CKD. In this paper, we present conceptual examples of risk factor modification for CKD, in the setting of this historical framework.
OBJECTIVE: Right-sided endocarditis (RSE) accounts for 5%–10% of all cases of infective endocarditis (IE) and frequently has different etiological, pathogenetic, and clinical presentations compared with left-sided endocarditis (LSE). The aims of this study were to evaluate the epidemiologic and clinical characteristics and prognosis of RSE patients and to compare them with those of LSE patients. This study’s importance relates to the local understanding of RSE and LSE, since Israeli demographics are different compared to the Unites States and Europe with regard to intravenous drug abuse and rheumatic valvular disease prevalence.
MATERIAL AND METHODS: A retrospective cohort study of 215 patients with infective endocarditis was performed. The primary outcome was in-hospital mortality. The secondary outcomes were duration of hospitalization, recurrent hospitalization, recurrent infective endocarditis, and one-year mortality.
RESULTS: Of the 215 patients in the study, 176 had LSE and 39 had RSE. The RSE patients were younger than the LSE patients (48.1±18.9 years versus 61.8±17.0 years, P<0.001). The most common pathogen in both groups was Staphylococcus aureus, which occurred more in the RSE group (51%) versus the LSE group (19%). In-hospital mortality was lower among patients with RSE (2.6% versus 17%, P<0.037).
CONCLUSIONS: Our study demonstrated an increasing percentage of RSE compared to LSE among patients with IE. Pacemaker lead infection has become the leading cause of RSE in intravenous drug users (IVDU), although less common in Southern Israel. The etiological and clinical differences between RSE and LSE are noteworthy. Patients with RSE have a better prognosis than those with LSE.
Therapy for inflammatory bowel diseases (IBD) has developed during recent years. Despite the availability of new therapeutic modalities, overall therapy success remains modest, and complete remission is usually achieved and maintained in approximately 30% of patients only. This observation can be explained by a number of reasons. First, the involvement of multiple genetic loci combined with differential environmental exposures suggests that IBD represent a continuum of disorders rather than distinct homogeneous disease entities. This diversity is translated into different disease course patterns, wherein some patients experience quiescent disease whereas others suffer from a relentless disease course. Hence, basic disease pathogenesis sets the stage for differential treatment responses. To date, IBD therapy is based on immunosuppression which does not take basic disease variability into account. Treatments are prescribed based on statistical considerations related to the response of the average patient in clinical trials rather than on personal considerations. Treatment outcomes can potentially be improved if physiologic considerations are inte¬grated into the drug selection process. In one approach, drugs can be targeted at known patient dysfunc¬tional processes such as in the case of patients carrying autophagy-related genetic polymorphisms being treated with rapamycin, a drug that inhibits mTOR inhibitor and enhances autophagy. Another alternative would be to use a systems approach to perform unsupervised, high-throughput screening in order to derive predictive treatment biomarkers and mechanistic insights associated with response to specific drug therapy. Additional predictive markers for drug safety are needed as well. Caveats and directions for needed future studies are outlined.
Background: United States (US) and European Union (EU) legislation attempts to counterbalance the presumed discrimination in pediatric drug treatment and development.
Methods: We analyzed the history of drug development, US/EU pediatric laws, and pediatric studies required by US/EU regulatory authorities and reviewed relevant literature.
Results: The US and EU definitions of a child are defined administratively (rather than physiologically) as being aged <17 years and <18 years, respectively. However, children mature physiologically well before their seventeenth or eighteenth birthdays. The semantic blur for these differing definitions may indicate certain conflicts of interest.
Conclusions: Pediatric healthcare today is better than ever. Regulatory-related requirements for “pediatric” studies focus on labeling. Most of these studies lack medical usefulness and may even harm pediatric patients through administration of placebo and/or substandard treatment, despite the resultant publications, networking, patent extensions, and strengthened regulatory standing. Clinicians, parents, and ethics committees should be aware of these issues. New rules are needed to determine new pharmaceutical dose estimates in prepubescent patients, and when/how to clinically confirm them. Internet-based structures to divulge this information should be established between drug developers, clinicians, and regulatory authorities. A prerequisite for the rational use of pharmaceuticals in children would be to correct the flawed concept that children are discriminated against in drug treatment and development, and to abandon separate pediatric drug approval processes.
United States (US) and European Union (EU) laws attempt to counterbalance the presumed discrimination of children in drug treatment and drug development. The US Food and Drug Administration (FDA)-rewarded pediatric studies with antidepressants triggered in 2004 an FDA black-box warning of suicidality in young patients. Fewer antidepressants were prescribed, and the number of completed suicides of young persons increased. The dilemma between this warning and the need to adequately treat young depressed patients remains unsolved. We analyzed the history of drug development, the evolving view of diseases in young patients, US/EU pediatric laws, and pediatric studies triggered by FDA/European Medicines Agency (EMA) in depression and other diseases on the background of developmental pharmacology; financial, institutional, and other interests; and the literature. The FDA/EMA define children administratively, not physio¬logically, as <17 (FDA)/<18 years old (EMA). But young persons mature physiologically well before their 17th/18th birthday. Depression occurs in young persons, has special characteristics, but is not fundamentally different from adult depression. Young persons are not another species. Regulatory requirements for “pediatric” studies focus on “pediatric” labels. Many “pediatric” studies, including those in depression, lacked and lack medical sense and harm patients by placebo treatment although effective drugs exist. The FDA has partially abandoned separate “pediatric” efficacy studies, but not in psychiatry. Clinicians, parents, institutional review boards, and ethics committees should become aware of questionable “pediatric” studies, should re-evaluate ongoing ones, consider to suspend them, and to reject new ones. The concept of separate “pediatric” drug approval needs to be abandoned.
Objective. To compare the reported accuracy and sensitivity of the various modalities used to diagnose autism spectrum disorders (ASD) in efforts to help focus further biomarker research on the most promising methods for early diagnosis.
Methods. The Medline scientific literature database was searched to identify publications assessing potential clinical ASD biomarkers. Reports were categorized by the modality used to assess the putative markers, including protein, genetic, metabolic, or objective imaging methods. The reported sensitivity, specificity, area under the curve, and overall agreement were summarized and analyzed to determine weighted averages for each diagnostic modality. Heterogeneity was measured using the I2 test.
Results. Of the 71 papers included in this analysis, each belonging to one of five modalities, protein-based followed by metabolite-based markers provided the highest diagnostic accuracy, each with a pooled overall agreement of 83.3% and respective weighted area under the curve (AUC) of 89.5% and 88.3%. Sensitivity provided by protein markers was highest (85.5%), while metabolic (85.9%) and protein markers (84.7%) had the highest specificity. Other modalities showed degrees of sensitivity, specificity, and overall agree¬ments in the range of 73%–80%.
Conclusions. Each modality provided for diagnostic accuracy and specificity similar or slightly higher than those reported for the gold-standard Autism Diagnostic Observation Schedule (ADOS) instrument. Further studies are required to identify the most predictive markers within each modality and to evaluate biological pathways or clustering with possible etiological relevance. Analyses will also be necessary to determine the potential of these novel biomarkers in diagnosing pediatric patients, thereby enabling early intervention.
Anti-citrullinated protein antibodies (ACPAs) are highly specific serologic markers for rheumatoid arthritis (RA) and can pre-date clinical disease onset by up to 10 years, also predicting erosive disease. The process of citrullination, the post-translational conversion of arginine to citrulline residues, is mediated by peptidylarginine deiminase (PAD) enzymes present in polymorphonuclear cells (PMNs). Calcium ions (Ca2+) are required for PAD activation, but the intracellular Ca2+ concentration in normal cells is much lower than the optimal Ca2+ concentration needed for PAD activation. For this reason, it has been proposed that PAD activation, and thus citrullination, occurs only during PMN cell death when PAD enzymes leak out of the cells into the extracellular matrix, or extracellular Ca2+ enters the cells, with the high Ca2+ concentration activating PAD. Recently, using artificial in vitro systems to corroborate their hypothesis, Romero et al. demonstrated that “hypercitrullination,” citrullination of multiple intracellular proteins, occurs within synovial fluid (SF) cells of RA patients, and that only modes of death leading to membranolysis such as perforin-granzyme pathway or complement membrane attack complex activation cause hypercitrullination. In order for Romero’s hypothesis to hold, it is reasonable to surmise that PMN-directed lysis should occur in the rheumatoid joint or the circulation of RA patients. Research conducted thus far has shown that immunoglobulin G (IgG) targeting PMNs are present in RA SF and mediate PMN activation. However, the role of anti-PMN IgG in mediating complement activation and subsequent PMN lysis and hypercitrullination has not been fully evaluated.
Ehlers–Danlos syndrome (EDS)—hypermobility type (HT) is considered to be the most common subtype of EDS and the least severe one; EDS-HT is considered to be identical to the joint hypermobility syndrome and manifests with musculoskeletal complaints, joint instability, and soft tissue overuse injury. Musculoskeletal complaints manifest with joint pain of non-inflammatory origin and/or spinal pain. Joint instability leads to dislocation or subluxation and involves peripheral joints as well as central joints, including the temporomandibular joints, sacroiliac joints, and hip joints. Soft tissue overuse injury may lead to tendonitis and bursitis without joint inflammation in most cases. Ehlers–Danlos syndrome-HT carries a high potential for disability due to recurrent dislocations and subluxations and chronic pain. Throughout the years, extra-articular manifestations have been described, including cardiovascular, autonomic nervous system, gastrointestinal, hematologic, ocular, gynecologic, neurologic, and psychiatric manifestations, emphasizing the multisystemic nature of EDS-HT. Unfortunately, EDS-HT is under-recognized and inadequately managed, leading to neglect of these patients, which may lead to severe disability that almost certainly could have been avoided. In this review article we will describe the known manifestations of the extra-articular systems.
Juvenile idiopathic arthritis (JIA) is the most common chronic disease of childhood. Improved understanding of its pathogenesis has led to international cooperation in clinical studies. Multicenter, international collaborations and research facilitate rapid enrollment of enough patients to enable a variety of studies, including those of epidemiology, diagnostic and classification criteria, genetic disease predisposition, pathogenesis, outcomes, and treatment protocols. In the last 20 years, the vision of the Pediatric Rheumatology International Trial Organization (PRINTO) has become a reality of worldwide collaboration in pediatric rheumatology research, including North American and European research groups. Major advances have been made in treating systemic JIA and its main complication, macrophage-activating syndrome (MAS). Single Hub and Access Point to Pediatric Rheumatology in Europe (SHARE) is a project of the European Society of Pediatric Rheumatology with the goal of improving clinical care. Based on evidence in the scientific literature, position papers regarding optimal clinical approaches and care have been published. Formal, validated assessment tools to evaluate response to treatment have been developed. Recommendations have been established to encourage international research collaborations, especially in light of major advances achieved in the genetics of pediatric rheumatologic diseases and the need to share biological samples among different countries and continents. Every participating country has disease information available for patients and families. Additionally, educational programs and updated syllabi for pediatric rheumatology have been written to promote similar, high-level academic training in different countries. These efforts have resulted in significant improvements in treatment and in patient prognosis. However, improved cooperation is needed to enhance research with biological and genetic samples. The Israeli Research Group for Pediatric Rheumatology is very active and has made significant contributions to the field.
