Occurrence rate

Although there is some evidence for the efficacy of long-term treatment with rifaximin for symptomatic relief in patients with uncomplicated diverticular disease, an unresolved issue is whether rifaximin can prevent major inflammatory complications of diverticular disease. In the two prospective open trials discussed above, the occurrence rate of complications in 12 months was lower in patients treated with glucomannan plus rifaximin compared to patients treated with glucomannan only 2.7 versus 0.9% [43] and 3.2 versus 1.3% [44], This observation was not confirmed in the double-blind placebo-controlled trial [45] in which no difference in the 1-year complication rate was observed between the rifaximin and placebo groups. However, in all the studies, the number of patients suffering complications in a 12-month period was too small to detect any statistically significant... 

The event tree can be used quantitatively if data are available on the failure rates of the safety functions and the occurrence rate of the initiation event. For this example assume that a loss-of-cooling event occurs once a year. Let us also assume that the hardware safety functions fail 1% of the time they are placed in demand. This is a failure rate of 0.01 failure/demand. Also assume that the operator will notice the high reactor temperature 3 out of 4 times and that 3 out of 4 times the operator will be successful at reestablishing the coolant flow. Both of these cases represent a failure rate of 1 time out of 4, or 0.25 failure/demand. Finally, it is estimated that the operator successfully shuts down the system 9 out of 10 times. This is a failure rate of 0.10 failure/demand. 

Severitv Rating Detection Rating Occurrence Rating RPN (Risk Priority Number) Max. RPN Tooling Factor Clamping/ Fixturing Factor Skill Factor Any Other Factor You Define Accumulated RPN Risk Associated ... 

Looking at the studies, the most frequently reported side effect is local, i.e. oral/sublingual itching (sometimes followed by gastrointestinal complaints such as stomach ache or nausea). These phenomena are always described as mild and self-resolving and only rarely did they lead to the discontinuation of the treatment. The occurrence rate of systemic side effects (asthma, urticaria/ angioedema, rhinitis) in the actively treated patients was indeed very low and... 

Figure 4. AE occurrence rate (left axis) and the curve of drying (right axis).

Figure 5. AE occurrence rate and the total energy released during drying.

Very informative plots are presented in figure 6. The envelope of AE occurrence rates and the theoretically estimated evolution of circumferential stresses based on the viscoelastic model are presented together in this figure. We can... 

Figure 6. Envelope of AE occurrence rates and the theoretical curve circumferential stresses.

The following conclusions can be drawn a) the AE occurrence rate descriptor is useful for determination of the periods at which the state of stress becomes destructive for the material b) three possible groups of AE occurrence rates may arise during drying first, during the heating of the material second, when the tensional stresses at the surface reach their maximum third, when the tensional stresses in the core reach their maximum after the stress reverse c) the descriptor of total energy reflects accurately the stress state in the material and indicates whether the material suffers the destruction or not. 

The inefficiency of nominal scale data is further exacerbated when one of the categories is rare. For example, a drug may produce a side-effect in a small proportion of users. In the example that follows, we will assume a 4 per cent occurrence rate. If we studied 500 patients that might sound like a perfectly adequate number. 

However, while that will produce plenty of individuals who are free of the side-effect ( 480), we would only anticipate finding 20 who do suffer it — a quite inadequate number. What we have to ensure is that we detect an acceptable number of individuals in all categories. The problem in this case is to accumulate sufficient individuals who do suffer the side-effect. We know from previous examples that (as an absolute minimum) any category with less than 50—100 observations will yield only a very imprecise estimate of the proportion. So, with a 4 per cent occurrence rate, we would have to observe 1250 patients to find 50 with the side-effect. Even having checked out over 1000 people, if we take the figures of 50 cases out of 1250, the 95 per cent Cl for the proportion with the side effect will be 2.98-5.24 per cent which is still not stunningly precise. 

A display of adverse events and occurrence rates. All new adverse events should be summarized in tables listing each event, the number of patients in whom the event occurred, and the occurrence rate. Although this information can be provided for all studies, excluding short-term studies (pooled together,... 

In our example, severity scores range from a moderate 5 to the highest severity of 10 because the customer could get injured by some failures. Occurrence ratings range from 3 to 7, predicting that some causes would occur very infrequently, while others could become a chronic issue. 

If you need a nnore granular or finely tuned approach for your severity and occurrence ratings, see Potential Failure Mode and Effects Analysis (2001), available from the Automotive Industry Action Croup at AIAC.org. 

The occurrence rate of product defect was adequately reduced by several improvements in the program but could not be less than a few percent. As mentioned before, LMOX and FMOX were sensitive to water and these defect prod-... 

Statistical analysis is performed on all parameters in the study. Its most fundamental objective is to determine whether administration of the test agent results in an increase in tumor incidence rates as compared to those in unexposed controls. Various statistical methods can be used. Tests for increased tumor occurrence rates between dosages may be based on pair-wise comparisons, such as the Chi-square test for 2x2 tables, the Fisher s exact test, or the Cochan-Armitage test. These tests are most appropriate when survival rates do not differ appreciably in the various dose groups. 

The adverse effects of beta-blockers are usually mild, with occurrence rates of 10-20% for the most common in most studies. Most are predictable from the pharmacological and physicochemical properties of these drugs. Examples include fatigue, cold peripheries, bradycardia, heart failure, sleep disturbances, bronchospasm, and altered glucose tolerance. Gastrointestinal upsets are also relatively common. Serious adverse cardiac effects and even sudden death can follow abrupt withdrawal of therapy in patients with ischemic heart disease. Most severe adverse reactions can be avoided by careful selection of patients and consideration of individual beta-blockers. Hjrpersensitivity reactions have been relatively rare since the withdrawal of practolol. Tumor-inducing effects have not been estabhshed in man. 

Fatigue is one of the most commonly reported adverse effects of beta-adrenoceptor antagonists, with reported occurrence rates of up to 20% or more, particularly in those who exert themselves. It has to be viewed alongside the ability to produce fatigue and lethargy by a possible effect on the nervous system. The precise cause of physical fatigue is not known, but hjrpotheses include impaired muscle blood supply, effects on intermediary metabohsm, and a direct effect on muscle contractihty (4). 

The complication risk in Type-I diabetes is related not only to duration of the disease but also to the degree of glycaemic control, blood pressure and genetic susceptibility (Hanssen, 1991). The most frequent chronic complication in Type-I diabetes is diabetic background retinopathy, with a near-100% occurrence rate after 15 years diabetes duration. Manifestations of diabetes, however, can be found in all ocular structures (Table 1). 

In children who had a stroke, chronic transfusions are successful in reducing stroke recurrence from approximately 50% to about 10% over 3 years. ° Since the first stroke in SCD is usually devastating, transfusions have been used to prevent the first stroke. In one trial, prophylactic transfusions significantly reduced the incidence of first stroke over a 2-year period in children 2 to 16 years of age with abnormal transcranial Doppler (TCD) ultrasonography. Stroke occurrence rate was reduced from 16% in patients receiving standard care to 2% in those who received prophylactic transfusions. ... 

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