Prospective approach

Prospective Approaches to More Efficient Flame-Retardant Systems... 

Performance qualification steps in a sterilization validation project usually require a prospective approach. The most common steps in prospective validation are the following ... 

FDA prefers prospective approaches because process reliability is established before release to the marketplace. 

The vulnerability of computer services to computer viruses is not easily managed. Besides deploying antivirus software the only other defense is to stop unauthorized software and data being loaded on computer systems and to build firewalls around networked applications. This is a prospective approach that assumes existing computer services are free from computer viruses. However, this approach cannot entirely remove the threat of computer viruses from computer services. The source of authorized software and data may itself be unknowingly infected with a computer virus. Novel viruses can also break through network firewalls. It is therefore prudent to check software and data related to computer services that are used within an organization. 

The Prospective Approach In this approach the routes of metabolism are first elucidated in microbial systems and then used to predict (and the metabolites facilitate the confirmation of) routes of metabolism in mammals. Also it could be used to explore unanswered questions in mammalian metabolism. For example, microbial studies may reveal a previously undetected mammalian metabolite, elucidate the previously unexplored stereochemical disposition of the xenobiotic in mammalian systems, or be used to study mechanistic aspects concerning the formation of the metabolites. 

An alternative method is the prospective approach, which uses patient information, such as serum creatinine, patient s age, weight, height, or body surface area to empirically estimate V, K, and creatinine clearance (Cl ). Adjustments to a maintenance dose are achieved through various approaches. The most significant application of either the retrospective or prospective approach is with regard to dosing adjustment in renal failure. ... 

To define a vaiidation strategy, we first must consider the current status of the system. If the system has already been installed, the validation will be retrospective if it is a new network, proceed with prospective validation. This chapter considers a prospective approach to vaiidation however, most of the concepts can aiso be used for retrospective vaiidation. It should be noted here that retrospective validation is usuaiiy a much more expensive and timely task compared to prospective validation. It has been suggested that retrospective vaiidation can be in excess of five times more expensive than prospective vaiidation [4]. 

The review of existing methods of evaluation includes a general description of retrospective and prospective testing and data sources available. For new systems of active safety a prospective approach seems nearly always to be most promising. However, the data sources available have deficits regarding the amount of data as well as depth of information and quality. Different methods of evaluation have been introduced especially their advantages and challenges with respect to validity have been discussed. 

The immobilization of phthalocyanines by covalent binding to inorganic macro-molecular carriers such as silica is a prospective approach to achieve heterogenous... 

In addition to providing advanced measures of both the lead dose and the toxic response portions of dose—neural response relationships, these prospective approaches helped to resolve interpretive questions not answered in earlier cross-sectional studies. For example, the inherent stability of the exposure measure is more discernible and quantifiable with serial measures of PbB or combined measures of blood and bone than isolated PbB measures done concurrently. One can also employ different statistical expressions of the exposure metric, e.g., average PbB, peak PbB, concurrent PbB, or lifetime integrated expression of exposure to estimate relative robustness of dose—response. Second, the potential confounding of dose—response relationships by any reverse causality is more reliably addressed. Reverse causality would hold that the dose term is elevated because of the higher likelihood of Pb exposures due to existing impairment of neurobehavioral function in other words, PbB levels rise with a higher frequency of abnormal hand-mouth activity because of neurobehaviors unrelated to Pb exposures. 

Thus, the question, whether ionic liquids (or at least the most common representatives among this enormous pool of compounds) can be viewed exclusively as baseline toxicants or whether there are some more specific effects and issues to look at beyond the side chain effect, needs to be answered for a prospective approach in ionic liquid toxicology. We think that the field of ionic liquid toxicology can only move forward if future research activities address more specific effects. To demonstrate the side chain effect again and again in more and more biological test systems simply consolidates the data already available, but cannot contribute substantially to the prospective design of inherently safer ionic liquids. 

There has been a welcome shift from the retrospective black spot engineering approach—where treatments are applied to sites (or lengths of road) with high casualty crash numbers—to the prospective approach of undertaking traffic safety risk assessments to identify sections with design, construction, or traffic management issues that may increase future crash probabilities. 

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