The well-being of individual human beings is defined in terms of their physical and psychological interactions with the environment. As long as these interactions remain within certain acceptable limits determined by individual experience, social custom and medical opinion the person is considered to be healthy. If they fall outside, however, the individual is deemed to be sick.
From the systems point of view the individual receives inputs from the environment and, after ‚processing‘ produces an output. In turn this output action feeds back on the environment, to close a mutually causal loop. Health and sickness are thus labels of quality assigned to the outputs of a decision process with multiple inputs (Fig.1). When the output of this decision process registers ’sick‘ the person becomes a patient and enters the sick care system. The aim of this system is to readjust the ‚process‘ in the individual which has given rise to those outputs which have generated the ’sick‘ signal. In particular, this is the explicit aim of classical medicine.
Until now the ‚Health Care Systems‘ in our society have been designed to work in this sickness loop, and have been consistently identified with ’systems to cure‘. In this sense we may view our medical services and hospitals as tools for the implementation of ‚cure‘-oriented system strategy.
Of course the above statements have oversimplified the true state of the present system. There are many medical examples which broaden the spectrum of health care delivered beyond the curative aspects alone. The important point, however, concerns the relative weighting of priorities, effort and expense. A pertinent contribution of the systems approach can be to assess all programs in terms of desirable priorities in order best to satisfy some overall objectives. Establishing these objectives is not conceptually easy and neither is implementing them politically. Thus, the ‚cure‘-oriented system strategy may not necessarily be the most desirable. In system terms, instead of interfering with the ‚process‘, the ‚output‘ of the individual may also be regulated by changing the ‚inputs‘. Furthermore, instead of the binary decision between ‚healthy‘ and ’sick‘ a continuous decision process producing more finely graded output may be devised. This takes into account that the causal relations between inputs and outputs typically take a long time to work themselves out.
Thus the aim of a good control strategy is to provide anticipation in modifying inputs. In such a Health Care System a ‚care‘-oriented strategy dominates. The evaluation mechanism of such ‚care‘- oriented systems (shown in dotted lines in Fig.1) receive information not only from the ‚output of the individuals and their environments but also from the ‚input‘. The result of the evaluation and decisionmaking process will appear primarily in terms of modification of the ‚input‘ to the individual, i.e. the control of the environmental influences on the body and mind.