Factors in improved survival from paediatric cancer

OBJECTIVES: The cost of providing services is the traditional criteria used by payers in making selective contracting decisions regarding home care providers in general, and home infusion therapy (HIT) vendors specifically for this analysis. This approach assumes comparable health outcomes, for which adequate measures often are unavailable. In practice, poor quality can result in a need for remedial services. The objective of this research is to develop a method to use health insurance claims data to incorporate the hidden costs of adverse outcomes into an analysis of the costs of a vendor's HIT. METHODS: The Home Infusion Therapy/Relative Benefit Index (HIT/RBI) model incorporates measures of both the cost of providing HIT services as well as the cost of remedial treatment for the adverse outcomes that may result from HIT care, eg, emergency room visits. The data source for the analysis is the health care claims for a sample of managed care patients of national insurer for the period 1990 to 1994. RESULTS: The analysis confirms that adverse clinical outcomes can lead to additional demand for remedial health care with resultant negative financial consequences. When the cost of the adverse outcomes is incorporated into the analysis, vendors who appeared to be low cost on the basis of HIT services, in fact were higher cost vendors, whereas vendors with a high cost of services but with few adverse events were low cost vendors. CONCLUSIONS: Payers should consider both the clinical and economic consequences of providing care into account in selecting vendors. The HIT/RBI model is a useful tool for incorporating the cost of adverse outcomes into a comprehensive comparison of the cost multiple vendors of HIT services.     

Flow control in message-switched communications networks

A queueing network model is used to analyse the performance of flow-control techniques. Analytical expressions for throughput and mean end-to-end delay are derived. Numerical results show that, under isarithmic control, the total network throughput is degraded significantly when the demand from one user is increased. Throughput degradation can be avoided if an end-to-end or a two-level control is used. Of these two schemes, the two-level control gives a higher throughput to the user with increased demand. This often results in a higher total throughput. The mean end-to-end delay of the various flow-control techniques is also characterized.     

A reappraisal of the stereoselective metabolism of nicotine to nicotine-1'-N-oxide

1. The cis and trans 1'-N-oxide metabolites of (2'R)-(+)-nicotine have the absolute configuration (1'S; 2'R) and (1'R; 2'R), respectively, and not the reverse as previously published. 2. Reinterpretation of metabolic data in the light of this reassignment reveals that N-oxidation of nicotine leads preferentially to the (1'R)-N-oxide, with little dependence on the configuration of the 2'-centre. 3. It is proposed that (2'S)-(-)-nicotine and (2'R)-(+)-nicotine bind to the same enzymic site by two distinct modes of binding; each of these modes involves the more basic centre (in this case the pyrrolidine ring) as the governing binding moiety.