Surgical management of trophoblastic disease
J. Richard Smith, Giuseppe Del Priore, Robert L. Coleman, John M. Monaghan in An Atlas of Gynecologic Oncology, 2018
Several factors may explain the high failure rate. First, MSP is limited when dealing with the occult and multifocal nature of the disease because of its limited resection approach. Second, histopathology of the focal uterine resection is fraught with difficulty: (a) diffuse disease may be missed, and (b) the fact that two patients had complete excisions demonstrates the difficulties of performing histopathology on electrodiathermied biopsies. In addition, it may not be possible to define a “safe” distance free margin in terms of single cells. Such a distance would depend on whether a knife or cutting diathermy (with consequent cautery damage) is applied. A cold knife may be used in future with intraoperative frozen section analysis (as with the last case) and a ≥5-mm safe distance to perhaps avoid the pathological concerns of residual disease. Finally, imaging modalities (Doppler USS, MRI, CT) may be excellent at detecting the main uterine lesion but not all the other metastatic disease sites within the uterus (Saso et al. 2012a).
B
Filomena Pereira-Maxwell in Medical Statistics, 2018
Or failure rate curve. A curve that depicts the hazard function (i.e. the conditional failure rate or force of mortality over time) as having three phases or periods: an early phase (also referred to as the ‘infant mortality’ period) during which the failure rate declines from a relatively high level, to remain fairly constant at a lower level throughout the intermediary period, which is then followed by the ‘wear out’ period of increasing failure rate. Given the constancy of the rate in the middle portion of the curve (in which failures are expected to take place at random), time to failure is modelled on the basis of the exponential distribution. This pattern is typical of the relationship between age and overall mortality rate in human populations, as shown in Figure B.2 (ENGELMAN, CASWELL & AGREE, 2014) with the Siler three-component competing risks model (SILER, 1979). It depicts the additive hazards that result from the action of three different hazard models, each of which dominates during prematurity, maturity or senescence. The age-related types of mortality are known as endogenous, exogenous or residual, and senescent. See also U-shaped curve.
Introduction
Mani Lakshminarayanan, Fanni Natanegara in Bayesian Applications in Pharmaceutical Development, 2019
Little research has been done to understand the failure occurring in the preclinical or early stage of the drug development. Failures occurring at the later stages of the clinical phase are a well-recognized industry-wide problem with published data showing that the failure rate is more than 50% (Grignolo, 2016). In an analysis conducted by FDA, it was shown that out of 313 new molecular entity (NME) submissions received in 2013, only 151 were approved, and nearly half failed because they could not show efficacy (Shanley, 2016). Furthermore, Pharmaceutical Research and Manufacturers of America (PhRMA) reported that in 2013 alone, companies have spent nearly $10 billion to run 1,680 clinical trials involving 644,684 patients. A 2014 report published by the Tufts Center for the Study of Drug Development suggests that the current cost of bringing a new medicine to market, estimated to be as high as $2.6 billion, presents a major barrier to investment in innovation in drug development. Such failures are costly and wasteful, not only for the pharmaceutical industries but also for patients who participate in these studies with an ultimate hope that these will result in cures for their ailments.
Comparison of two point-of-care respiratory panels for the detection of influenza A/B virus
Published in Infectious Diseases, 2023
Alexandros Zafiropoulos, Aspasia Dermitzaki, Nikos Malliarakis, Marina Stamataki, Maria Ergazaki, Evangelia Xenaki, Maria-Eleni Parakatselaki, George Sourvinos
Regarding the influenza detection, the BioFire RP2plus had a PPA reaching 100%, whereas QIAstat-Dx RP exhibited significantly lower PPA at 89.29%. When comparing the detection of negative samples, NPA was the same for both methods. Other studies have also evaluated the efficiency of the above methods to detect the influenza A/B viruses by estimating their sensitivity and specificity. For the BioFire RP2plus, sensitivity has been estimated at 100% and specificity at 100% and 99.9% for influenza A and B viruses, respectively [14]. The authors also refer low failure rate, which agrees with the findings of the present study. For QIAstat-Dx RP, sensitivity varied between 94.6% and 99.2%, depending on the subtype, while specificity varied between 99.5% and 100% [15]. According to another study, sensitivity was between 75% and 100%, while specificity was between 99.8% and 100% [4]. Taken all together, BioFire RP2plus and QIAstat-Dx RP seem to both have high performance in detecting the influenza virus, however, QIAstat-Dx RP had the disadvantage that it gave more invalid results.
Exponentiated odd Chen-G family of distributions: statistical properties, Bayesian and non-Bayesian estimation with applications
Published in Journal of Applied Statistics, 2021
M. S. Eliwa, M. El-Morshedy, Sajid Ali
MTTF, MTBF and AvB are reliability terms based on methods and procedures for lifecycle predictions for a product. Customers often must include reliability data when determining what product to buy for their application. MTTF, MTBF and AvB are ways of providing a numeric value based on a compilation of data to quantify a failure rate and the resulting time of expected performance. Also, In order to design and manufacture a maintainable system, it is necessary to predict the MTTF, MTBF and AvB. If 16) when r = 1. The AvB is consider the probability that the component is successful at time x, i.e.
Tibial Intraosseous Insertion in Pediatric Emergency Care: A Review Based upon Postmortem Computed Tomography
Published in Prehospital Emergency Care, 2020
H. Theodore Harcke, Riley N. Curtin, M. Patricia Harty, Sharon W. Gould, Jennie Vershvovsky, Gary L. Collins, Stephen Murphy
Failure to achieve satisfactory placement in 40% of our documented insertions (Table 1) was an unexpected finding. First-attempt success was achieved in over 80% of pediatric patients by Myers et al., but this series had patient groups with median ages 1.6 years (manual placement) and 0.98 years (drill placement) (3). While a 60% placement success was disappointing, it is comparable with the overall success rate of 65% reported by Pifko et al. (4). Since all but one failure occurred in infants 6 months or younger (Table 2), we follow the pattern of a high failure rate reported by Pifko et al. (4) in infants less than 8 kg; they equated 8 kg to an average age of 6 months, so, although we grouped by age, comparison is valid. Given the high failure rate in this age group, focus was on the infants younger than 6 months. Selection of needle length was an important parameter; our data show a 25-mm needle was not successful in six out of seven placements in our series when the infant was 2 years of age or younger. The 25-mm needle was also used in five out of six cases in which the needle perforated both cortices of the tibia. Although the 15-mm needle is designated for pediatric use in the weight range of 3–30 kg and 25-mm needle for greater than 3 kg (10), we did not expect to encounter the 25-mm needle in young infants. Our data show that successful use of the 25-mm needle is possible in cases where the child was older than 2 years, but we have very few cases to support this finding.
Related Knowledge Centers
- Coefficient of Variation
- Conditional Probability
- Exponential Distribution
- Redundancy
- Weibull Distribution
- Reliability Engineering
- Mean Time Between Failures
- Failure Modes, Effects, & Diagnostic Analysis
- Survival Function
- Memorylessness
- Coefficient of Variation