Semiotics and Decision Making Using AHP in Medicine

Abstract

This chapter discusses the intricate relation of medical semiotics and medical decision making. From the very beginning to arrive in a medical context, some signs have to be perceived by the person him/herself, by others, or by using some instruments. If these show a deviation from the corresponding normative sign, the process of collecting signs and necessity for a decision making is proximate. We discuss some types of medical signs directly related with the decision-making process, for example, normative signs, intra- and inter-subjective signs, subjective and objective or instrumental signs, scalar signs, etc. These signs create configurations of signs, and configurations of signs are the fundament of medical and decision rationing. The model of Analytic Hierarchy Process (AHP) uses criteria that are scaled for decisions among different options, but in medicine to set criteria and scale values is a semiotic process because it refers signs. An example of AHP decision making was given for a domestic medical decision about addressability, that is, going to the medical institutions or not, but AHP can be used, and already was, in most of medical decision realm, from addressability to diagnosis, treatment, follow-up, public health policies, or strategies.

1. Introduction

One of, if not the most important problem in medicine, is finding grounds for therapeutic action. Any physician-patient relationship, as well as the whole field of practical or community medicine, aims for action, and action in medicine follows decision making (DM). For its part, DM must be based on a set of data that are entirely of the nature of signs, whether they are subjective (what a person feels) or objective (what can be observed from the outside), or instrumental, through paraclinical means. Before introducing these signs into an evaluation system leading first to a diagnosis and then to therapeutics, they must be defined. The discipline that deals with the definition and discussion of signs is semiotics. Semiotic accuracy is the first step towards a correct medical decision. The notion of “health”, together with the other associated concepts (disease, illness, well-being, quality of life, etc.), defines a whole semiotic realm, which was and is conditioned both historically and culturally and without which medicine cannot work. Thus, the two fields, semiotics and decision making are sine qua non conditions within any medical practice, permanently involved at every level of evaluation and action, often intricate and even difficult to distinguish at first glance (the diagnosis itself is a decision based on signs to which a certain value is assigned).

In this chapter, I first describe diverse types of signs used in medical context (explaining the difference with pathological signs, related to diseases, subchapters 1 and 5) and their significance for the DM process in a point where Semiotics and Analytic Hierarchy Process (AHP) converge: the scales for degree descriptions of signs (subchapter 2). I explained in a simple example how an AHP can model the first issue of medicine, that is, addressability (analysis made in subchapter 3), and then how qualifying the signs with different determinations can increase their values in formatting reliable criteria for AHP (Figures 1–4). In the 6th subchapter, we discuss a model about how successive configurations of signs lead to successive layers of decisions related to all stages of medical reasoning and acting (see Figures 5 and 6), and in the last one, a brief description of domains where AHP (a general model described by Figures 3 and 7) was already used in medicine and most probably will be used extensively in the future, beginning with patients’ decisions to public health policies. A general flowchart of this chapter methodology is illustrated by Figure 8.

Figure 1.

Range of values as normative sign against which non-normal variations are established.

Figure 2.

Patient-physician communication adapted from R. Jakobson model.

Figure 3.

Construction of a decisional hierarchy with 4 criteria and 4 options.

Figure 4.

Succession of signs from facts to expression.

Figure 5.

Subjective, objective, and instrumental signs (S) make signs configurations (Cf) that generate a decision making (DM) process among different options (O).

Figure 6.

Successive configurations of signs Cf/S/ lead to successive decision-making DM, from home decision to medical follow up.

Figure 7.

Hierarchical structure for the AHP modeling of a problem with four criteria (C) and four options (O) the number of criteria and options may vary according to the specific task of DM.

Figure 8.

Semiotics, decision-making, and AHP.

1.1 Signs in a medical context and pathological signs

To arrive at a diagnosis, the medical experts (physicians) must specify a number of signs that they learned in medical school, the so-called/disease signs/ or /pathological signs/. Pathological signs are those signs which the patient presents that represent deviations from/the normal/ and through which the physician can potentially define a possible disease. The discipline that studies such signs related to possible diseases is academically called medical semiology. In what follows, we will not discuss this discipline as defined in medical textbooks. We will rather focus on its theoretical foundations from the broader perspective of medical semiotics [1, 2], and semiotics as C. S. Pierce [3], C. W. Morris [4], U. Eco [5], and others [6] defined it.

From the very beginning, it must be stated that not all the signs that a physician takes into account are necessarily pathological signs. Certain signs that may not be directly correlated with a disease (habits, hygiene, mentalities, work stress, and even the person’s temper or behavior), but which signal a deviation from a state considered by the patient or the physician as /normal/, can still become signs in a medical context.

The medical context is that context in which details of the private or the public life of a person or a community are connected to a possible impairment of health or well-being. A conjunctural sadness may not necessarily be a feeling connoted as having pathological significance, but when the sadness is prolonged or when it becomes a possible cause of a psychological (depression, burn out syndrome) or immunological disorder, it becomes significant in a medical context. That is why signs in a medical context could be defined as any signs that can lead to or show a disturbance in the person’s state of normality, regardless of their nature. Sometimes, these signs are not immediately connoted as pathological signs, rather as the “way of being” of the person, but even this way of being can be the source of possibly pathological deviations. For example, a person defines themselves as follows: “I get angry very easily, sometimes I become violent verbally or physically …” that’s how I am, there’s nothing I can do about it“; it is a state of irritability, nervousness that they consider normal for themselves, but when it is at the origin of behavior disorders, we already have a deviation from normality, which often requires medical intervention (psychotherapy, behavioral therapy, medication) following a DM within the medical spectrum. A certain gene that provides information for making a protein on the surface of the white blood cells, called the HLA B27 complex, can be present normally in some people, but in the context in which they present joint or spine pain, or digestive disorders, this presence becomes indicative of a group of diseases called Spondyloarthropathies or the Inflammatory Bowel Disease (IBD), although it is part of the person’s genetically determined “way of being.” The same is the case with all genetic disorders or genetic predispositions: in these cases, we have a deviation from a statistical /normality/, compared to other people, but the person in question does not have a deviation from themselves.

In this instance, I am referring to the medical context as a part of the medical communication structure, which aims to convey medical signs—from transmitters to receivers, through transmission channels, according to R. Jakobson theory of communication [7]—and possibly help to make a decision. It is defined every time there is communication in which a potential medical decision could be made, hence its pragmatic dimension.

2. Normality as a /normative sign/ with reference value

The most typical example of a medical context is that of the physician-patient relationship, but before reaching this phase, there are some previous stages. In the simplest terms, it all starts when a person “doesn’t feel good anymore,” “doesn’t feel able to do something,” or simply “feels that something is wrong.” Other times, the person does not feel anything, but the laboratory analyses are deviated from /normal/, or those around notice a change in their state, behavior, abilities, and make the assumption that something has changed, and this something is of a medical nature. In other words, the beginning of the medical context is a deviation from a state implicitly or explicitly assumed to be that of /normality/. Normality can be defined in many ways, the simplest and the vaguest definition is that of World Health Organization (WHO): “health is not merely the absence of disease or infirmity but a state of complete physical, mental, and social well-being” [8]. What is of interest here is not only its denotative value as a generic signs/health/, but the deviation from it felt subjectively (displeasure, pain, helplessness, etc.), objectively apparent (changes in appearance, functionality) or revealed only by paraclinical instruments (laboratory, imagistic). As G Canguilhem [9] and M. Foucault [10] stated the concept of health or disease is determined not so much by science as by the idea of cultural determined normativity, “but normality has no consensual definition in medical literature” [11, 12, 13].

Every time a medical context appears, the signs presented, either by themselves or by others (family or physician), are compared explicitly or implicitly with what is considered to be /normal/. But normality itself is constituted by signs, which are mental or social representations of normality. These signs that explicitly or implicitly define normality and that are compared to the patient’s signs each time, one by one, are normative signs [14]. In the terms of C. S. Pierce’s semiotics, their referent or object is that which is considered normal, their representation is the way they express themselves (e.g., the color of the face or the acceptable range of an analysis), and their interpretant is either a person or a system in which they function as values ​​of reference [15]. Without normative signs, medicine would not be possible because, at each stage of the evaluation in a medical context (whether it is about addressability, diagnosis, or treatment), what is ab-normal or dys-functional is defined in relation to them. Punctually, each normative sign becomes the center of a semiotic field, or the reference value in which the actual signs discovered in real patients fit [16].

2.1 Normative signs are qualified

If we take an implicit normative sign, for example, /normal hair/, around it we can describe variations in which qualifications are implied. /Normal pubic hair/ is normative to the adult age, but if it appears as /precocious pubic hair/ we have a variation from the norm and the possibility of some hormonal disturbances such as too early puberty: here the qualification of the normative sign is age. If an adult male presents /loss of hair/, this situation can be sometimes considered /normal/, if it is an inherited hormonal family feature: this is a gender qualification of /normal hair/. But if this condition is disturbing for the person, they can request treatment or even implantation, and this is the reverse process, whereby entering a medical context (address a physician for implantation) transforms a trivial personal feature into a sign that demands choice in the DM process. If the /falling of hair/ is a deviation from /normal hair/, a physician has to qualify the new sign and, according to certain determinants, decide if it is pathological or not, or if it is the object of a medical DM. For example, this sign can be qualified by (a) Age: it is closer to normal in older age; (b) Physiological situation, for example, after pregnancy and long breastfeeding; (c) Medical condition, if it appeared after chemotherapy; in this case even if the /falling of hair/ is non-normal, it is not considered pathological in itself, but rather an /iatrogenic sign/ induced by therapy, and as such it is not directly connected with a specific DM; (d) Type, if it appears in small spots, the so-called alopecia areata (if it is total, alopecia totalis), and it implies not just the scalp hair but also axillar, pubic hair, and eyebrows.

What we generally call laboratory findings, all refer to certain normative values, and can be directly related with a DM. Their general model is a certain interval where the measured parameters are being considered normative, so the normative sign /S/N ranges from values X to values Y. What is lower than that value is considered hypofunction or /S/− values; what is above are hyperfunctions or /S/+ values; the values increase numerically, according to the arrow (Figure 1).

Many parameters are described by just one interval as /S/N = X → Y, so, apparently, an interpretation of this type of signs is rather simple. However, for certain substances, the normative sign /S/N is qualified by physiological determinants (e.g., the blood sugar interval 90–110 mg/Dl is normative just in the morning, before eating). Therefore, instead of having just one normative interval we will have more, qualified by determinants. For example, when taking into consideration the so-called ∼hormonal constellation∼ in women, there is a set of four hormones: Estrogens, Progesterone, FSH (Folliculin Stimulating Hormone), and LH (Luteinising Hormone). The normative values for these are dependent both on age and the period of menstrual cycle. There are five types of normativity: (a) Before first menstruation; (b) In the folliculinic phase of the cycle—therefore making the sample is recommended in day 3–4; (c) During ovulation; (d) In the progesterone phase of the cycle—recommended in day 22–23; e) After menopause.

Now, the normative sign becomes /normative sign in certain conditions/ and these conditions are classified according to certain criteria. If the normative sign is properly classified, it will function as a reference for the comparison of the actual sign of the person (patient) and it will become a trustful factor for a medical DM.

2.2 Types of scales for normative signs

Scaling is an important process in Analytic Hierarchy Process (AHP) for DM as stated by Thomas L. Saaty [17]. To decide whether a sign is pathological or not in a medical context, and hence its use for a AHP in DM, several types of scales are being used, in which the normative sign can be located:

1. at the beginning of the scale (“my head doesn’t hurt” as beginning for pain scale) and the pain scale goes up;

2. in the middle of the scale (e.g., laboratory values). From there, the scale goes up and down: the values are ​​very low—lower—/normal/—higher—very high;

3. at the end of the scale (“I feel tired”), where the scale starts from the normative sign “normal energy” and goes downwards.

The scaling expression is essential for each of the DM moments, because it can lead to one decision or another depending on the relative importance given to that sign; in other words, the gradation of the signs is the expression of their assigned value. There are several grading possibilities, which are used daily in any medical context, both by people with different conditions and by physicians, as shown by E. Cirino [18]:

1. The type of scaling through easily definable categories, Categorical Scale (CS), in degrees: not at all—a little—medium—a lot—very much—worst possible.

   Categorical scales (CS):

   

   For children and for some patients, the representation may be iconic.

   

2. In the form of numerical values, Numeric Rating Scales (NRS), for example, define pain (or worsening, improvement after treatment) from 0 to 10.

   Numerical rating scales (NRS):

   

3. Of the type of percentages: “what percentage is better/worse”, widely used for the subjective evaluation of improvements or worsening after a treatment (“I feel ∼50% better”), but also for pain as in the Visual Analog type Scales (VAS)

   Visual analog scale (VAS):

   

4. The qualitative type, for example, pale-yellow-normal-congestive-cyanotic. In the case of qualitative signs, for example, the color of the face, the scaling is more difficult. In this case, the normative sign is in the center of the semiotic field which it generates. When the physician sees the color of a patient’s face as a sign and interprets it as /pale/ or /congestive/, the normative sign /normal color/ is implicit. Around this sign, a whole contextual semiotic field unfolds, wherein variations of nuance may represent medical signs [16].

   For the formalization in AHP, a scaling of the criteria represented by these signs is needed. The first three types of grading are easily translated into a system from 1 to 9, with odd “strong” values.

   • “not at all,” 1.0% = AHP scaling 1.

   • “a little,” from 1 to 3, up to 30% = AHP scaling 3,

   • “medium,” from 3 to 5, up to 50% = AHP scaling 5.

   • “a lot,” up to 7, up to 75% = AHP scaling 7.

   • “very,” up to 10, or 100% = AHP scaling 9.

2.3 The physician-patient relationship as a semiotic process in the DM perspective

When presenting to the physician, the person is subjected to an interrogation, clinical examination, laboratory tests or imaging, so that the physician can make a decision. The decision involves three aspects: (1) what is it based on? (2) what diagnosis does the patient have? (3) what treatment is to be prescribed (prescription of drugs, recommendation of lifestyle modification, prohibitions, or even surgery, etc.). Throughout the whole process, from the feeling that “something is wrong” to a medical action, everything involves signs. The patient perceives their condition as a sign of something, they communicate the condition to those around them or to the physician, the physician adopts diagnoses or treatments, and the final evaluation, if the medical decision was correct, is also made through signs.

At every moment of this continuous semiosis, every semiotic level is accompanied by a decision. From the first moment of the patient’s presentation to the physician, an interpersonal relationship is established between the two that is neither neutral nor generic, but has a cultural predetermination that involves all kinds of expectations when entering into such a relationship. The physician-patient relationship, right from its inception, has a certain meaning for both. In semiotic terms, any patient in front of a physician is a source of signs embedded in the generic sign of /patient/. Conversely, the patient perceives the person in front of them under the sign /physician/, who in this context is not just a human being in general, but is coded as /physician/ (given the place, gown, stethoscope, hospital). Each of the two parties is involved in a communication relationship as senders and receivers of messages in the form of signs. According to Roman Jakobson’s model, any communication relationship involves a sender, a receiver, a message, code transmission channels, and a context (Figure 2).

Between the patient and the physician, what is exchanged are messages: not unidirectionally, rather in both directions (e.g., the patient says what hurts, the physician explains what it could be). These messages are of the nature of the signs themselves, the interview revealing a twofold possible centering that should be integrated [19].

In this communicative ensemble, the context is particular, defined on the coordinates of the so-called “medical consultation,” whose purpose is to issue a decision regarding the patient’s state of health. This context is from the very beginning oriented by specific concepts that permeate the consultation framework, such as for example that of “diagnosis” and “what needs to be done.” In other words, the meaning of the signs is pragmatically conditioned by their use and the perspective of a DM. On the other hand, this communication has specific codes, from the coding that appears through space, the relative position of the two, the dress code of the physician, to verbal codes (the specific language of both, which are controlled by the code) or psychological (the patient knows they have to answer questions because they encoded the assumption that the physician will help them). We identified several types of codes in the medical context: descriptive, associative, prescriptive, and permissive codes [20].

3. Domestic medical DM, the issue of addressability

Before a person goes to the physician when certain signs suggest that a possible medical problem has arisen, there is always the question of a decision making: “what do we do, stay home or go to the physician?” It is the issue of addressability: deciding between domestic medical action or addressing a physician or a medical institution.

3.1 “The child has fever” and the AHP modeling in DM

When the notification of non-normality is made by others, for example a mother who notices that the child has a fever (or a social group that notices a violent behavior), the supposedly non-normal person is the object of perception from the outside, and the judgment of their condition is a reporting to the idea of ​​normativity. It is a process of comparison between two categories of signs: (a) signs by which the state of that disturbed person is perceived (for example, the red face of the child and the high temperature of the forehead felt on the hand by the mother) and (b) signs that represent normality, normative signs (the mother tells herself “before, the child was normal”). From the comparison between the two strings of signs, the non-ordinary, non-normal state is inferred, and from here the path to the decision-making process is opened.

Any referral to a physician requires that the potential patient or people around them make the decision. Although the process seems simple and is usually undertaken without full awareness of the decision moments, it could be modeled because it essentially includes all the stages that can give rise to a Hierarchical Analysis Process (AHP). Generally speaking, in any AHP there is a specific structure, where T = Task; O = Options, O1, O2, O3, O4 and C = Criteria C1, C2, C3, C4.

Thus, for example, in a context where the child has a fever, the mother is faced with the following options (O): (O1) to do nothing and wait for it to pass by itself; (O2) to start self-medication (e.g., anti-thermic); (O3) to contact the family physician; (O4) to go to the Emergency Room.

What would be the criteria (C) that the mother implicitly or explicitly takes into account to make this decision? (1) C1 = cost in time, energy of mother or money; (2) C2 = risks, the uncertainty of the diagnosis (is it a simple virus, or it hides a complicated diagnosis); (3) C3 = aggravation in time or amelioration; (4) C4 = safety, accessibility of the physician or the feeling of being safe of the mother towards her decision about child. If we take into account the four options for action and the four criteria, an initial scheme of an AHP can be made. The APH structure of this DM problem (“the child has a fever - what do I do?”) is as follows, yet the number of criteria or options can be variable from case to case and from problem to problem (Figure 3).

According to AHP, the criteria will each be scaled from 1 to 9, where 1, 3, 5, 7, 9 represent degrees of importance assigned by the decision maker: 1 = unimportant, 3 = a little important, 5 = medium importance, 7 = high importance, 9 = very high importance. The even numbers 2, 4, 6, 8 = represent transition values ​​between the odd degrees. Here beneath an example how this problem can be formulated and solved in terms of AHP, using the model for medicine conceived by Dolan et all [21, 22]:

• Step 1. Setup the hierarchy

• Step 2. Pairwise comparisons.

A. Comparison matrix of the 4 criteria vs. goal.

Criteria vs. goal	MC	MR	MA	MS	Weights
Minimize cost (MC)	1	1/3	1/4	1/2	0.15
Minimize risk (MR)	3	1	1/2	1	0.39
Minimize aggravation (MA)	4	2	1	2	0.26
Maximize safety (MS)	½	1	1/2	1	0.18

B. Comparison matrix of the 4 alternatives vs. MC.

Minimize cost	DN	ST	FD	H	Weights
Do nothing (DN)	1	3/2	2	5/2	0.37
Self-treatment (ST)	2/3	1	5/3	2	0.28
Family Doctor (FD)	½	3/5	1	3/2	0.19
Hospital (H)	2/5	½	2/3	1	0.13

C. Comparison matrix of the 4 alternatives vs. MR.

Minimize risk	DN	ST	FD	H	Weights
DN	1	2/3	1/3	1/3	0.13
SD	3/2	1	1/2	2/3	0.19
FD	3	2	1	3/2	0.39
H	3	3/2	2/3	1	0.29

D. Comparison matrix of the 4 alternatives vs. MA.

Minimize aggravation	DN	SD	FD	H	Weights
DN	1	2/3	1/2	1/2	0.13
SD	3/2	1	1/2	1/3	0.17
FD	2	2	1	2/3	0.3
H	2	3	/2	1	0.39

E. Comparison matrix of the 4 alternatives vs. MS.

Maximize safety	DN	SD	FD	H	Weights
DN	1	3/4	1/3	1/2	0.13
SD	4/3	1	1/2	2/3	0.17
FD	3	2	1	2	0.44
H	2	3/2	1/2	1	0.25

• Step 3. Weighing the decision elements.

The weights were determined using the method of normalized row sums. That is, each weight was computed by summing the values of the corresponding row and then divided by the sum of the elements in the matrix. This gives an acceptable approximation of the normalized eigenvector of the comparison matrix.

• Step 4. Synthesis.

The following table captures the information distilled thus far:

Criterion
	Minimize; Cost	Minimize; Risk	Minimize; Aggravation	Maximize; Safety
Alternative	0.15	0.39	0.26	0.18
DN	0.37	0.13	0.13	0.13
ST	0.29	0.19	0.17	0.17
FD	0.2	0.39	0.3	0.44
H	0.13	0.29	0.39	0.25

From this table we read:

$$\mathit{DN}=0.37\ast 0.15+0.13\ast 0.39+0.13\ast 0.26+0.13\ast 0.18=0.16$$

$$\mathit{ST}=0.28\ast 0.15+0.19\ast 0.39+0.17\ast 0.26+0.17\ast 0.18=0.19$$

$$\mathit{FD}=0.19\ast 0.15+0.19\ast 0.39+0.3\ast 0.26+0.44\ast 0.18=0.33$$

$$H=0.13\ast 0.15+0.29\ast 0.39+0.39\ast 0.26+0.25\ast 0.18=0.27$$

In conclusion, the final ordering of our options is:

$$\mathit{\text{Family doctor}}>\text{Hospital}>\text{Self}-\text{treatment}>\mathrm{Do}\text{nothing}.$$

Of course, the assignment of priority numbers and the whole AHP mathematical process will not be done by a mother with a feverish child (who may not know matrix math and never heard of eigenvector), but essentially, she makes the decision unconsciously, while prioritizing in fully unexpressed and unformalized scales, according to her judgments.

3.2 Addressability as a decision-making problem

Decision models like the one discussed above can fit into the broader category of DM that has as its object the addressability to a physician or a medical institution, and represents in itself a medical, but domestic decision, in which one chooses between several options. This is one of the serious problems in medicine because, on the one hand, an excess of addressability unnecessarily burdens the medical system with things that could be solved domestically, but, on the other hand, the lack or delay of addressability can lead to the serious evolution of some diseases with complications. The two extreme situations were both present during the COVID-19 pandemic and both proved their disadvantages and consequences [23]. Many other examples can be given:

• The lack or scarcity of addressability in particular communities: remote, or poor, or lacking medical institutions. In these cases, although there might be an addressability decision, achieving it is difficult and may involve insurmountable logistical problems.

• Lack of addressability for certain social categories, for example, in less educated, poor or middle-class environments under the influence of ideological or religious factors.

• The lack of addressability that appears through previous experiences interpreted as unpleasant: long waiting time for consultation with the GP or specialist, the experience of unsatisfactory or superficial treatment felt by the patient in some situations in the past (sometimes precisely through the overloading of the GP or the emergency system).

• Lack of addressability for personal reasons, of a psychological nature (e.g., “fear of the physician,” or mistrust of the physician/medicine).

• or the nature of some personal beliefs (e.g., neglecting certain symptoms “for which I don’t think I need to go to the physician”).

4. From sensation to the medical sign—intrasubjective and intersubjective semiotic processes

The moment of emergence of a medical context is that of a deviation from what the patient or those in their immediate social environment consider to be normality. In the patient’s language, they can be expressed verbally (“I don’t feel well,” “it hurts,” “I’m sick,” “I cannot,” etc.) or non-verbally (through changes in color, dynamics, behavior).

A first level of meaning, the intra-subjective one, is that in which the person realizes that, in one way or another, they have moved away from their previous state. This realization occurs as a result of an immediate fact, which can be a sensation or a certain state of fact of the nature of Firstness, in Pierce’s terminology [24, 25]. This fact is imposed on the patient as something more or less defined, which they enter a relationship with (of the nature of Secondness), while entering a relationship with themselves comes to be interpreted also as a disturbed state, or as pain, following an act of mental representation that functions as an interpretant of the nature of Thirdness. Expressing it is the next step, through which this process becomes presentable to others (words) or to themselves (groans).

Thus, we have signs that follow each other and that generate other signs at each step: (a) a first chain is intra-subjective, from sensation, to perception, to mental representation, as “not good,” “discomfort,” “illness”; (b) from this mental representation sign to its expression in other communication systems, the transition from the intrasubjective level to the inter-subjective level of signification, in which all possible categories of signs (indexes, icons, or symbols) can be used.

For example, when a child puts his hand on his abdomen and squirms because of a tummy ache, the sign is of the nature of the index. When a throbbing pain is signified by a gesture such as clenching and unclenching the fist, the representation is iconic, an image of the type of pain which is felt. All verbal expressions are symbolic representations and appeal to a conventional language to translate a particular sensation [26]. It is worth noting that when dealing with verbal signs there is most often an intentionality of the sufferer. Sometimes, however, para-verbal emissions (e.g., moans of pain or interjections) are merely indexes and not symbols and indicate the referent directly, from the physiological fact to its non-intentional expression.

Non-verbal expression can lead to signs that are transmitted through any channel: visual (gestures indicating pain or sensation), auditory (sighing, moaning, sound of voice), olfactory (smell of sweat or breath). Non-verbal signs can in their turn be intentional, for example, they indicate the location of a pain, or non-intentional, for example a hunched position during colics. These unintentional signs express disturbances at the organic level, for example, an intense spasm that compels yawning. Intentional and non-intentional signs, as well as verbal and non-verbal signs, can be associated, so that repetitions of messages with the same referent appear, which increase their semiotic value for the decision-making act. If the child moans, always puts his hand to his ear and says “it hurts”, this complex of different types of signs transmitted through different channels but having the same referent makes the mother or the physician take the child’s condition seriously, to think of otitis and be on the verge of making a decision.

We can summarize the appearance of these signs through a sequence of stages from sensation to expression, as in the Figure 4 (transformed from [24]):

In the conception of C.S. Pierce, any sign has a triadic structure, in which the Referent (or the object of the sign) is what is referred to, the Representamen (or the sign itself) is what the referent represents, and the Interpretant is the one through which the representation is correlated as being of the object [3, 27]. The primary intrasubjective referent is an undefined sensation caused by a fact or by physiological change and the first sign is established when this sensation becomes a perception that represents the sensation (something is perceived as /painful/). The second semiotic level is that of the perception that has become a referent which causes a mental representation to be defined (something is perceived as/burning pain/). The third semiotic level is the one in which this representation is expressed verbally (“my head hurts”) or non-verbally (I point my finger to my temple, meaning that it hurts there). An expression of this course is:

$$\mathrm{F}\to /\mathrm{S}/\left(\mathrm{f}\right)\to /\mathrm{P}/\left(\mathrm{s}\right)\to /\mathrm{R}/\left(\mathrm{p}\right)\to /\mathrm{E}/\left(\mathrm{r}\right),$$E1

in which each semiotic level is an interpretant for the previous one and becomes an object for the successor. In this way, there is, on the one hand, the preservation of the original referent along the entire chain, and on the other hand, the need for an interpretation, sometimes possibly even distortion, of the message at each transition from one level to another.

This chain F → S → P → R → E is conditioned at each stage:

• F → S, like S → P, are indexical or direct signs, but the semiotic process can be interrupted. For example, if the nervous system is embodied by a peripheral paralysis, or the patient is unconscious, S no longer passes into P, although the physiological fact F (burning or nerve irritation) exists.

• The mental representations of some P → R perceptions are iconic signs, already conditioned not only by what is felt as a perception, but also by the mental interpretation by which that sensation is represented (pain is represented “as if … it is burning,” “as if … it is a stich,” “as pressure”).

• The expressions from R → E are symbolic signs, which already need certain expression codes. These can be clearly established by the convention of the spoken language in a certain language (“it hurts,” “mă doare,” “ça fait mal”) or, as it happens in the case of certain expressions of pain established by unconscious cultural conventions (“oiii,” “auuuu,” “auhhh”).

• Some non-verbal expressions such as the posture during pain (e.g., /bend double/), the type of walking (/stumble walking/), the color of the face or palms (/pale face/, /yellow palms/) can be direct expressions of certain physiopathological facts (pain, paralysis, jaundice) and are iconic signs; the referent is that fact and the expression is no longer subjectively mediated by S, P, R, but a direct relationship F → E is established.

• In certain psychosomatic conditions, we can focus on the mental representation (R) that is expressed (E) toward oneself or others even in the absence of a determining F physiological or pathological fact. This retrograde path, from the expression to the representation of sensations or perceptions, depends on one’s own production of mental signs that build their own representation, sometimes up to the reverse reconstruction and the appearance of sensations or perceptions (a simple example is a fever with muscle pain that appears after anger or sadness).

4.1 “A burn,” signs as criteria directing to DM

The question that arises is whether this semiotic chain has any importance for clinical medicine and the process leading to DM? Is the process of signifying simple facts of this kind somehow related to the decision process, or in other words, how are the two processes interconnected in a medical context? Let us take a simple example, a burn at home, and examine several situations as possible options for action, decisions, and addressability in simple “if-then” decision terms, where O are options:

1. A 1st degree burn with local redness leads to options O1 = do nothing, or O2 = apply ice.

2. A 2nd degree burn over a larger area leads to O2 or further to apply an O3 burn spray.

3. A 3rd degree burn (bullae), on some surface, leads to O2, O3, and possibly O4 = an analgesic drug and to O5 = local dressing.

4. A 3rd degree burn with large extension can determine either O1 → O5 or directly O6 = presenting to the emergency room.

5. A 3rd degree burn with a large area can determine O7, calling the ambulance, where a specialized treatment will begin.

For all these options, the decision mechanism is one: Fact → Decision → Option, wherein the criteria (C) are not very elaborate, but are based on objective (what is seen) and subjective (what is felt) signs that are relatively easy to understand: C1 = degree of burn, C2 = its surface, C3 = pain, C4 = anxiety about pain or complications. The scaling of the criteria is in large steps, of the type “a little- normal -a lot” for the degree, extent, or intensity of the pain. This way, the decision variants are according to the objective or subjective scaling of the signs and we can design a simple map of AHP.

It is worth noting that in the semiotic chain from F to E, the intensity of each of the component elements can be scaled either spontaneously (as it happens in a burn) or according to easily decipherable scales (degree of burn, surface), so that each sign is associated a degree, which will eventually become a criterion and a decision factor. For example, the pain can be relatively easily interpreted from 0 to 9 or in simple forms such as weak, medium, intense, excruciating. In this interpretation, any of the elements of the semiotic chain can be decisive for making a decision.

5. Types of medical signs

In medical DM processes, we always operate with signs of different types and origins. They can be synthesized, from a semiotic point of view, in several categories [28].

5.1 Subjective signs, objective signs, instrumental signs

A first and classic classification of medical signs was made according to their field of provenance or source. Subjective signs, commonly called symptoms, represent a subjective experience that cannot be identified by anyone else, its referent is about how the patient feels, reacts, or behaves in certain conditions, and the means to obtain them is mostly by their being spoken. Objective signs (sometimes called simply signs, in medical language) are observable phenomena that can be identified by another person, be it non-medical (e.g., family) or a medical person. Their domain is very vast, and they can be: (a) static, resulting from the appearance of some parts of the body (color, swelling, dryness, cracks, symmetry, etc., of eyes, skin, tongue, limbs), to the specific appearance of some injuries (rash, eruptions, ulcers), or (b) dynamic: walking, breathing movements, movements of parts, speech as phonation, voice sound, etc.

The instrumental signs are those for which an external source, device, or instrument is used. Among the first signs of this kind were those that amplified or clarified the ordinary senses with simple instruments: stethoscope, otoscope, ophthalmoscope, dermatoscope, microscope. In parallel with the scientific and the technological development, three other large categories of instrumental signs appeared: (a) laboratory signs, which are obtained through specific analyses of body fluids (blood, urine, cerebrospinal fluid, pleural exudate, etc.) or other products (stool, stones, sputum, etc.); (b) imagistic signs, in which iconic images of parts of the body are formed by means of instruments based on physical phenomena. The first type was the Roentgen machine, but now this field has become extremely broad (Magnetic Nuclear Resonance, ultrasound, Computer Tomography, etc.); and (c) graphic signs, wherein the instruments translate a bodily function into a graph, with symbolic signs (Electrocardiography, Tympanography, Electromyography, etc.).

5.2 Simple signs—qualified signs

Simple signs are those that generally signal a fact from any of the above categories. These signs often have a simple index value, e.g., subjective /pain in the wrist/, or objective/swelling of the wrist joint/, or instrumental /temperature of 39 degrees Celsius/. For the patient, they can be at the origin of a DM related to domestic treatment (H) or addressability (A). It should be noted that instrumental signs (laboratory, graphic, or imagistic) are actually never simple signs, because they require an interpretation of the entire generated semiotic field. For example, the image of a formation will be qualified by size, location, relationships, intensity of the image (e.g., on ultrasound transparent for a cyst, or hyperechogenic for a tumor).

In making a diagnostic decision, these simple signs are of little semiotic, and implicitly decisional value. Therefore, through medical questions and investigations related to professional skills, the physician will try to find out as many details as possible about these signs; in other words, they will try to add them qualities, to qualify them [29]. Thus /wrist pain/ must be qualified:

• In context (after what it appeared? After a stress, cold, other illness, or other treatment?);

• In time (when is it? Day-night, morning-evening, summer-winter?);

• In quality (how is it? sharp, weak, burning, stitching, excruciating?);

• In localization (where is it? Just a fist-to-both, does it radiate to the fingers or elbow?);

• In modalities (how does it get worse or better? Hot – cold, movement – ​​rest?);

• In association (with what is it associated? With restlessness, or fever, or vomiting?).

This process is extensively use in homeopathy, where the qualifications may lead to a DM for homeopathic remedy as treatment [16].

The qualifications by objective signs are being added (the hand is very swollen, hot, he cannot move it). And after the DM to do investigations, laboratory signs (high Blood Sedimentation Rate, high level of uric acid, high level of fibrinogen) or imaging (signs of inflammation of the metacarpal joints) may appear as necessary for a diagnosis DM. Thus, qualified and determined signs on all directions of medical investigation, when put together, better define the diagnostic criteria and implicitly a diagnostic DM.

5.3 Present signs and historical signs

Historical signs are those reported by the patient about personal or family illnesses or result from medical records of the patient. Although they are apparently not related to the actual main complaint, they can qualify actual signs. For example, the patient remembers that they had episodes of wrist pain several times, in the cold or during the holidays (when they ate more pork, sausages, smoked meat), but they ignored them, as well as the fact that the patient’s father and family had gout.

Historical signs can be personal (e.g., a patient had recurrent purulent tonsillitis as a child and now he complains of strong joints pain) or they may run in the family (e.g., a patient with a mammary lump has a mother operated for breast cancer). If the actual signs define a synchronic consideration of the current signs, the historical signs define a diachronic perspective, wherein the past and the present signs are connected. This connection can be decisive for scaling certain criteria for the diagnostic DM.

5.4 Scalable signs and iconic signs

As we have seen, most of the signs that are considered in a DM can be scaled. The subjective signs are being scaled by intensity scales, the laboratory signs by the normality range against which everything plus or minus can be scaled (e.g., hemoglobin - /normal / or slightly low, very low, increased, very increased). However, some pictorial or graphic signs are difficult to scale. (For example, the presence or absence of a kidney stone on urography or the presence of fibrillation on EKG). These are iconic signs directly related to a certain pathology, and although they reach the physician when mediated by the appropriate instrument, they have an “either-or” meaning. In other words, they are eliminative signs, high-graded criteria that can exceed all the others.

Other signs are characteristic of only one disease; they are also called pathognomonic signs, and they have the highest specificity and high positive predictive value (e.g., Koplik’s spots in measles). Most often they are found by the physician simply because they look for them in a certain configuration of other signs.

6. Semiotic and decision chains in medicine

The stages of the entanglement of semiotics with those of the medical DM can be formalized. If we make the following observations:

1. /S(s)/—subjective signs, intra- and intersubjective (from 1 to n—as many as collected).

2. /S(o)/—objective signs (from 1 to n).

3. /S(i)/—instrumental signs (from 1 to n).

4. /S/ means that it is about signs.

5. Cf /S1/—Configuration of signs.

6. O = possible options or alternatives.

7. DM 1 = domestic care or addressability.

8. DM2 = diagnosis, DM3 = treatment etc.

We can formalize the relationship between them, so that we consider the first configuration of signs Cf/S1) as the qualified sum of the totality of the subjective signs /S(s/), the objective signs /S(o)/ and the instrumental ones /S(i) where each domain of signs can take values ​​from 1 to n. Thus Cf/S1/ is:

$$\sum _{k=1}^n\left(S_k\left(s\right)+S_k\left(i\right)+S_k\left(o\right)\right)$$E2

Then, Cf/S1/ faces the options O1, O2, O3, … On, from which the first decision DM1 is made (Figure 5).

The first decision leads to the continuation of the process on the next level, for example, from addressability to the medical consultation, where the same structure, with the three types of signs, will lead to a new configuration Cf/S2/, which faces other options, that leads to a new DM2 decision, the one of the diagnosis. Then, the DM3 therapeutic decision will follow that of the DM4 evaluation and the process can continue until the desired result is obtained.

It is worth noting that in a configuration of signs, the signs relate: (a) on the one hand to their referent; (b) they relate to each other and this valorizes them through association; (c) on the other hand, their value is modulated from the DM perspective that will follow (e.g., the perspective of a gout diagnosis makes the relative value of the uric acid analysis potentiate the objective sign /join swelling /). They do not simply add up, but their summation increases the possibility of confronting the normative configuration of the /diagnosis/; in other words, they tend to constitute meaningful configurations for the DM, in which purely semiotic interrelationships and those that foreshadow the DM are specified step by step.

What should be emphasized in the case of the former is that they take place in from the first signs that appear in the personal life of a person, before the person becomes a patient, until treatment and then evaluation. Medical decisions are not always simple, but they are always based on configurations of signs that are enriched at each level. If we call the household decision H (home decision), that of Addressability = A, Diagnosis = D, Treatment = T, Evaluation of evolution = E, Follow-up = F, we obtain a course, where each decision is preceded by the formation of a semiotic configuration Cf/S/ (Figure 6).

After each configuration of signs, a DM follows, based on certain criteria C, and taking into account the options O. Passing from one level of DM to another implies a new configuration of signs, some continuing those from the previous level, others being reconsidered, and others resulting from the anamnesis, observations, or the prescription of paraclinical and laboratory analyses and investigations. For example, the first configuration of signs /S1/ related by patient is not enough for the physician to evaluate the patient and make a DM. They will reevaluate and deepen their evaluation by asking questions about the subjective signs S(s) that thus will become better defined; they will observe the objective signs S(o) and will discover new ones or qualify them. Eventually, they will request and then interpret the required analyses.

It should be noted that the request for analyses and investigations (imaging, genetics, graphic tests, EKG, or EEG) is itself a DM step on the part of the physician, who must decide between several alternatives O: (a) if they must be done; (b) what investigations should be done, so as to bring information that is relevant to the case (e.g., to ask for an HLA B27 test in some persistent joint pains, but not other genetic tests); (c) evaluate the cost-benefit ratio of certain tests (e.g., decide that an expensive MNR is not needed in a panic attack). It is only after the new configuration of signs has been made, with the additions related to the physician’s expertise, that the decision regarding the DM(D) diagnosis can be made, and even for this a proper arrangement of signs as criteria can lead to an AHP. But even in this instance, there are one or more intermediate steps, namely those of possible decisions on the DM(Dd) differential diagnoses, and the investigations can be done in several stages, as the logic of the diagnosis advances [30, 31].

The final goal of the entire situation that is created in the physician-patient relationship is the treatment. Starting from the patient’s signs and taking into account the normative signs from science and the physician’s experience, a new problematic configuration is formulated, wherein therapeutic options must be chosen based on certain criteria. Between the medical signs resulting from the consultation and analysis, the diagnostic decision, and the therapeutic decision, there is a connection that is sometimes expressed in models recommended by the respective specialties.

Medical treatments are probably the thorniest problem of medicine and lend themselves best to the AHP because in the very way they are formulated there is a hierarchy of criteria. In all these processes, however, an AHP-type initiated algorithm can be applied, as in the scheme below, yet wherein the number of criteria and options is different from case to case. In essence, it is all about establishing the objective (T = task), a number of criteria (C), from C1 to Cn, and choosing between a number of possible options (O) from O1 to On, then passing through an evaluation of the criteria in the given concrete situation (Figure 7).

7. Areas in which APH can be applied in medical DM

AHP is an attracting model for DM, and after Saaty published his initial works about AHP but especially after 1997, the model was tested to formalize medical decisions. In a review published in 2008, Liberatore and Nydick considered already 50 articles about AHP classified in seven categories: diagnosis, patient participation, therapy/treatment, organ transplantation, project and technology evaluation and selection, human resource planning, and health care evaluation and policy [32]. For a review of the wider use of AHP, see also Ho [33]. Each stage of an approach in a medical context implicitly or explicitly has a DM correlative, and a possible use of the AHP model. The fields in which they can be used are:

1. Domestic (as in the examples above) and patients medical decisions [34]

2. Addressability to physician or medical institutions, screenings [35].

3. The diagnosis. Any diagnosis is a decision, not a simple linear path or summation of symptoms and signs

4. Treatment with multiple variants, depending on the criteria present in the patient, for example, breast cancer [34] or antibiotic therapy [36].

5. Medical evaluation (follow-up), wherein the treatment and its possible continuations are assessed (e.g., the decision to continue or stop chemotherapy).

6. Quality evaluation of different aspect of medical activity: medical records [37], health supply [38, 39]

7. Public health policies [40], vaccinations [41, 42], health planning policies [43]

The number of medical studies in different fields multiplies fast, as the method is appealing and necessary in complicated decision processes. In a recent (2022) scoping review about AHP use in medicine, the authors conclusion (and we join it) is: “Despite the compelling rationale on the potential for decision analysis to support shared decision-making, rigorous randomized controlled trials are needed to confirm these interventions’ effectiveness, while qualitative studies should seek to understand their potential implementation” [44].

A general methodological flowchart of some main interactions among Semiotics, DM and AHP is shown in the Figure 8.

8. Conclusions

The two processes, the process of signifying, of giving meaning, and the one related to making decisions, are permanently inextricably intertwined in medicine:

1. From the meaning given to signs to the domestic decision, the way a person or those around interpret and act in the state of non-well.

2. For addressability to a medical institution, the decision based on the interpretation of certain signs that decide addressability.

3. In diagnosis, each step towards a diagnosis requires mental operations that help to make certain decisions, while the diagnosis itself is a decision.

4. For treatment: from the multitude of treatments, given the individual signs of each patient, the decision of one treatment option or another is mandatory.

5. In the follow-up and management of any medical case and depending on the reaction of the patient or the disease, or other criteria (e.g., cost-benefit), the way of evaluation, continuation, interruption of treatment is decided (interruption of treatment is a clear case of DM, based on semiotic criteria).

6. To state or regional medical policies, for example, vaccination, anti-smoking campaigns, or reduction of schooling, corporate stress, etc.

7. To the attitudes and the construction of a certain medical paradigm within a community, either at the state level or at the level of certain micro-communities that share the same beliefs and values. By interpreting certain social signs in a certain way, attitudes and actions are predicted and campaigns are conducted (e.g., “drink water regularly,” “excessive alcohol consumption damages your health,” “get vaccinated,” “exercise 30 minutes a day,” etc.) and promote a certain medical image of society, by encouraging values ​​or denigrating habits, beliefs, and activities.

8. It finally leads to the outline of one of the most important health problems, that of the /normal/ as a reference image whereby normality is described, not only in the medical, but also in the paramedical problems (e.g., homosexuality, now treated as becoming part of normality, after it was previously considered a pathology or abnormality, compared to natural norms).

Acknowledgments

I express my gratitude to Oana Georgiana Gabor who helped me in the translation and arrangement of the English text, and to Bogdan Carasca for his help in mathematical processing of the example of AHP as domestic medical DM.