Automated Multiphasic Health Testing

Abstract

ADVANCES in automation and instrumentation have brought medicine and allied disciplines to the brink of a new era in health care. It is now feasible to screen total populations or selected subgroups for asymptomatic disease at reasonable cost and with minimal use of physician time. Medical personnel and facilities will be progressively incapable of delivering health iservices if the population born after World War II in the United States is allowed to enter middle age with undetected and unaltered disease. Because of this population boom the portion of the population aged 25 to 45, for example, will increase by 69 percent by 1990 (1). Chronic illness costs our economy an estimated $57.8 million annually. Included in this amount are direct costs of treatment and care and the loss of present and potential income (2) . Total health care implies a continuum from prevention to early detection of a disease through the stages of clinical disease, rehabilitation, and demise. Clearly, prevention and early detection are the first-and only the first-steps toward solving this situation. We define the word very explicitly. It is the presumptive identification of previously unrecognized disease or defect, by the application of tests, examinations, or other procedures which can be applied rapidly. This is the definition of the Commission on Chronic Illness Conference (3). The salient points of this definition are presumptive, unrecognized, and rapid. For most investigators, screening implies only the differentiation of normal from abnormal, hence the emphasis on the word presumptive; we have progressed little if we redetect previously known disease, hence unrecognized is stressed. To be sure, there is a place for surveillance of subjects with known disease for a status check or a followup, but none of these is screening. The special feature of modern screening clinics is rapidity, which reduces both the costs and the loss of time for patients and personnel alike. Traditionally, disease detection proceeds through a progressive system of procedures and tests that enable the physician to arrive at a definitive diagnosis. A classic example of such a uniphasic series of tests can be drawn from pulmonary tuberculosis detection; presumptively afflicted persons are identified by mass chest X-ray units. Positive skin tests for tuberculosis delineate some of these persons as probably tuberculous, and obtaining a positive culture for tuberculosis definitely diagnoses the disease. Note that mass X-ray is the screening procedure in this example. Those involved in health testing have long known that health-service consumers, like other consumers, prefer one-stop service. So several tests are performed at a single visit, but each series of tests from presumptive to definitive is unidirectional, that is, it leads to one diagnosis independently. An example of another series of tests that could be performed in conjunction with tuberculosis detection is glaucoma testing. The presumptive tests for this prevalent disease, subject to some local option, are tonometry (the indirect measurement of pressure within the eye) lor visualization of the retina by photography, or both. Additional information for the The authors are with the Medical Systems Development Laboratory, National Center for Health Services Research and Development, Health Services and Mental Health Administration, Public Health Service. Dr. Ayers is the plulmonary project officer, Dr. Hochberg is chief of the Medical Development Unit, and Dr. Caceres is chief of the laboratory. Portions of the paper were given at the 70th annual meeting of the American Hospital Association, Atlantic City, N.J., on September 18, 1968.