Health link: a wide area telecommunication network for health care providers




McDaniel, James Grennell

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Early computerized health information systems supported applications in hospital records and laboratory data collection. Since that time, software has been developed for a number of health care providers such as doctors and pharmacists. Although local area networks are installed at larger institutions, only a few small-scale, special-purpose, wide-area networks are installed for external providers. To be adopted, wide-area networks should provide greater functionality than, and be cost-competitive with, conventional communication methods. Several projects are underway in Health Information Science to develop and evaluate generic, wide-area networks. This dissertation describes the design, analysis, development, implementation and evaluation of a prototype health care network which would be accessible to providers using existing computer equipment and the public switched telephone system. The network software, Health Link, supports reliable, automatic, store-and-forward messaging of medically-sensitive information. Encrypted messages can be authenticated and the software features registered delivery. An application programming interface formats messages in accordance with the HL7 data interchange standard. Simulation studies have been conducted which demonstrate the steady state characteristic behaviour of a node in a uniform cluster. Further studies have investigated a realistic, dynamic, large scale network. A peer-to-peer model and client-server model were analyzed and both were found to be feasible with respect to certain performance and cost criteria. The client-server model was found to be less costly to operate than the peer-to-peer model. The peer-to-peer model can transfer messages in a shorter time than the client-server model. The network software was verified in a field test involving four clinics, one medical laboratory, and one hospital. Data collected in the test provide performance benchmarks, an estimate of message sizes and frequencies, network reliability statistics, and a wealth of observations. Performance benchmarks and message traffic measurements were used to calibrate the simulation models. Results from this and other research indicate that, although most of the technical networking problems can be readily overcome, consensus on standards, health care applications, and initiatives should be promoted before a wide-spread, production network is implemented.



Medicine, Communication systems, Medical care, Computer network resources