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.
Introduction. The current study evaluated the rate of ependymal enhancement and whether its presence influences survival of patients with malignant glioma (GBM).
Methods. A retrospective review of all patients who were treated in our institution from 2005 to 2011 was conducted. Data extracted from the medical records included age, date of diagnosis, co-morbidities, treatment regimen, and time of death. Magnetic resonance images (MRI) were evaluated for the presence of ependymal enhancement and its extent, and the correlation to survival was investigated.
Results. Between 2005 and 2011, 230 patients were treated for GBM. Eighty-nine patients were excluded from the study due to insufficient data, leaving 141 patients for analysis. Median age at diagnosis was 60 years. Sixty-seven (40.6%) patients had evidence of ependymal enhancement on MRI (group A), and 70 (42.4%) patients did not have evidence of enhancement. The assessment of ependymal enhancement was inconclusive due to mass effect and ventricular compression that precluded accurate assessment for 28 (17%) patients (group C). Median survival was 14 months for group A (range, 12–16 months), 15.9 months for group B (range, 14.28–17.65 months), and 11.7 months for group C (range, 6.47–16.92 months) (P>0.05). A multivariate analysis to predict survival indicated that male gender (P=0.039), hypertension (P=0.012), and biopsy only compared to complete gross tumor resection (P=0.001) were significant for poor survival.
Conclusions. Pretreatment ependymal enhancement on MRI was not found to be associated with poorer survival. These results might be due to better treatments options compared to prior reports.
An anniversary is not only a point of memory—it provides the opportunity for self-examination and paves the way to the future. Every anniversary marks a starting-point that was preceded by a vision. The beginning of any vision is a personal dream—someone wants to improve or repair the world as far as he is able. The vision motivates action; in its aftermath comes the reality. This is the 21st issue of Rambam Maimonides Medical Journal. This issue is particularly important as it marks the completion of five years of creative work pursuing our vision for a high-caliber scientific medical journal. Our vision has become reality.
As I shared in my January 2015 editorial, the furor surrounding publication in The Lancet of the open letter by P. Manduca et al. carried potential for bad and for good. Here at Rambam Health Care Campus, we have chosen and will continue to look for the good.
Background: Estimates of lifetime cancer risk are commonly used in the clinical setting and in health-care evaluations. These measures are based on lifetime cancer risk estimates and may create an unrealistically frightening perception of cancer risk for an individual. We suggest using two new measures of cancer risk to complement the cancer lifetime risk measure, namely estimates of cancer risk from birth to a specific age or from a specific age to life expectancy.
Methods: We calculated risks using incidence density data from the Israel National Cancer Registry of 2013, applying a well-known formula for calculating risk, for a follow-up time. The joint disease-free survival probability is calculated for several age intervals, and hence the risk (i.e. 1–survival) for the intervals.
Results: The risk of cancer to age 80 in Jewish men and women, respectively, ranged from about 0.336 and 0.329 at age 0, to 0.279 and 0.237 at age 60. The risk of cancer from birth up to an age in Jewish men and women, respectively, ranged from 0 and 0 at birth to 0.088 and 0.129 at age 60. The risk of cancer to age 80 in Arab men and women, respectively, ranged from 0.298 and 0.235 at age 0 to 0.249 and 0.161 at age 60. The risk of cancer from birth up to an age in Arab men and women, respectively, ranged from 0 and 0 at age 0 to 0.074 and 0.095 at age 60. In Jewish and Arab women, breast cancer risk to age 80 decreased from about 0.127 in Jewish women at age 40 to 0.079 at age 60 and from 0.080 to 0.043 in Arab women; the risk from birth up to a specific age ranged between 0 and 0.056, and 0 and 0.040, respectively.
Conclusion: The two proposed new estimates convey important additional information to patients and physicians. These estimates are considerably lower than the frequently quoted 33% lifetime cancer risk and are more relevant to patients and physicians. Similarly, breast cancer risk estimates up to or from a specific age differ considerably from the frequently quoted lifetime risk estimates of 1 in 8 women.
Azoospermia, the absence of any sperm cells from the ejaculated semen, poses a real challenge to the fertility urologist. While there are options to create happy families for azoospermic couples, such as the use of donor sperm and adoption, most couples still want to have genetically related offspring. Advances in urology, gynecology, and fertility laboratory technologies allow surgical sperm retrieval in azoospermic men and achievement of live births for many, but not all azoospermic couples. At present, there are extensive research efforts in several directions to create new fertility options by creating “artificial sperm cells.” While these new horizons are exciting, there are significant obstacles that must be overcome before such innovative solutions can be offered to azoospermic couples. The present review article defines the problem, describes the theoretical basis for creation of artificial genetically related sperm cells, and provides an update on current successes and challenges in the long tortuous path to achieve the ultimate goal: enabling every azoospermic couple to have their own genetically related offspring. Hopefully, these research efforts will ripen in the foreseeable future, resulting in the ability to create artificial sperm cells and provide such couples with off-the-shelf solutions and fulfilling their desire to parent genetically related healthy babies.
A 20-year-old female patient was admitted to hospital because of bilateral leg weakness. Laboratory investigation showed metabolic alkalosis and severe hypokalemia. Differential diagnosis included mineralocorticoid or apparent mineralocorticoid excess diseases, with a high aldosterone-to-renin ratio (ARR) after correcting hypokalemia. After confirmatory tests, imaging studies revealed a unilateral adrenocortical adenoma consistent with Conn’s disease. Surgery was curative.
Diabetes and hyperglycemia are present in over one-third of inpatients in internal medicine units and are associated with worse prognosis in multiple morbidities. Treatment of inpatient hyperglycemia is usually with basal bolus insulin in a dose calculated by the patient’s weight, with lower doses recommended in patients who are at a higher risk for hypoglycemia. Other antihyperglycemic medications and insulin regimens can be used in selected patients. There are no adequately powered studies on the effect of improving glycemic control on hospitalization outcomes in non-critically ill patients in internal medicine units, and in most patients a modest glucose target of 140–180 mg/dL is recommended. A structured discharge plan should intensify antihyperglycemic treatment as needed and include an outpatient follow-up appointment shortly after discharge.
The strong relationship between cardiovascular diseases (CVD), atherosclerosis, and endogenous or exogenous lipids has been recognized for decades, underestimating the contribution of other dietary components, such as amino acids, to the initiation of the underlying inflammatory disease. Recently, specific amino acids have been associated with incident cardiovascular disorders, suggesting their significant role in the pathogenesis of CVD. Special attention has been paid to the group of branched-chain amino acids (BCAA), leucine, isoleucine, and valine, since their plasma values are frequently found in high concentrations in individuals with CVD risk. Nevertheless, dietary BCAA, leucine in particular, have been associated with improved indicators of atherosclerosis. Therefore, their potential role in the process of atherogenesis and concomitant CVD development remains unclear. Macrophages play pivotal roles in the development of atherosclerosis. They can accumulate high amounts of circulating lipids, through a process known as macrophage foam cell formation, and initiate the atherogenesis process. We have recently screened for anti- or pro-atherogenic amino acids in the macrophage model system. Our study showed that glycine, cysteine, alanine, leucine, glutamate, and glutamine significantly affected macrophage atherogenicity mainly through modulation of the cellular triglyceride metabolism. The anti-atherogenic properties of glycine and leucine, and the pro-atherogenic effects of glutamine, were also confirmed in vivo. Further investigation is warranted to define the role of these amino acids in atherosclerosis and CVD, which may serve as a basis for the development of anti-atherogenic nutritional and therapeutic approaches.
We are proud to introduce you to the Fifteenth Annual Rambam Research Day, now established as a key annual event at Rambam Health Care Campus, Haifa, Israel, reflecting the diverse research activities on our campus.
