Retrospective sources

Graphical User Interfaces Informing Models Prospective Sources Retrospective Sources Expert Opinion Robustness (What-If Analyses)... 

A variety of data sources are available to inform interactive programs, including prospective data sets, retrospective databases, expert opinion, and unpub-lished/published literature. Time horizon, that is, the length of time into the future considered in the analysis over which costs and outcomes are projected, is very important here [26]. For example, if a clinical trial or the published literature only report short-term results for a chronic condition, the outcomes may come into question. This is where decision-analytic models may come... 

A number of interactive program developers advocate retrospective analyses and modeling as alternatives to prospective data sources. These sources... 

Develop policy-supporting SOPs on computer systems. These may include development, testing, maintenance and support, quality assurance, change control, source code management, system retirement, retrospective evaluation, evaluation of vendor-supplied systems, etc. 

One response may be that it is possible to manage the red tide at the source of the bloom (8) or that there is no need to manage a red tide over vast areas, merely in localized ones that are of special interest. The point is moot until a suitable control agent is available. A considerable number of chemicals have been reviewed for possible red tide control substances, (9), and in retrospect this type of research is subject to ultimate failure because the first criterion of a successful control agent (chemical or biological) has not been considered. 

After the initial inventory reporting cutoff in May of 1978, this retrospective approach was replaced with the flow of current information. New substances, as they became commercial, had to be identified and put through a decision process as shown in Figure 2. New reports were again necessitated by the commercialization of a new substance. Since July of 1979. Section 5 Compliance has been the source of nearly all compliance activity. Input for Premanufacture Notification purposes now takes a shape similar to that previously indicated, (see Figure 2) but now incoming new product material must reach the coordinator earlier in the life of the product than at any other time in the compliance effort. This introduced a potential time delay in the commercialization process. 

The diagnosis can be clarified by collecting a retrospective history both from the patient and from a collateral source, such as a friend or family member. A history of bipolar disorder will include episodes of illness that typically arise spontaneously, last for days or weeks, and often result in a decreased need for sleep during times of hypomania or mania. The periods of affective lability in the patient with a Cluster B personality generally do not arise in this spontaneous fashion but are instead triggered by a stressful life event. In addition, they seldom last as long as the typical... 

One can readily see that the conclusions of the authors are based on numerous assumptions rather than on factual data. Unfortunately, this is the nature of retrospective epidemiological studies. One cannot really fault the authors for their sequence of theories leading them to a possible source of the infections. Such efforts are necessary for sorting out the potential source of infections and. through follow-up studies and designed experiments, we can determine sources of infections and methods for prevention. They evidently did omit some observations on the meat samples they did check and observations on the adjacent dairy herd and. they did not take samples from the cattle s environment on the beef farm. If the beef farm was thought to be the source, there should have been more effort to find the organism on that farm. 

Radiation Personnel Accident. Radiation exposure in accidents of personnel in nuclear facilities and non-destructive detection have been evaluated with ESR dosimetry. For example, the amputated medium fibre bone of a worker in Peru, who tried to solve the problem by directly touching the source of 60Co unit for a few seconds, was measured four years later.The dose was measured by 6.4 + 0.5 Gy, while 20 + 3 Gy was obtained from fluorescence in situ hybridization method. The result would suggest diagenic decay of the signal due to the metabolism of bone.96 Thus, ESR gives the retrospective dose for radiation accidents. 

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