Acta psychiat. scand. (1975)51, 51-66 University Department of Psychiatry (Heads: Professor Villars Lunn, Professor Ole J. Rafaelsen, Thorkil Vanggaard, M.D., Erling Dein, M.D., Preben Hertoft, M.D.), Rigshospitalet, and Department of Psychiatry (Heads: Andrej Myschetzky, M.D., Mogens Nimb, M.D., Allan Vangrorp, M.D.), Bispebjerg Hospital, Copenhagen, Denmark

EMPIRICAL INVESTIGATIONS O N T H E RELIABILITY A N D T H E VALUE FOR D I F F E R E N T I A L D I A G N O S I S O F 21 CLINICAL SYMPTOMS O F D I S T U R B E D STATES O F CONSCIOUSNESS A. AGGERNES, A. MYSCHETZKY, H. PAWN AND J. VITGER

Two groups of patients in disturbed states of consciousness (DSC’s) were compared with three groups of patients in clear states of consciousness (CSC‘s): demented, schizophrenic, and non-psychotic patients. In each of the groups, 15 patients were evaluated for 21 “objective” symptoms; each patient was evaluated by two psychiatrists. In this way, reliable symptoms were sought out which could discriminate: 1) elderly patients in DSC‘s from elderly demented but clear patients; and 2) schizophrenic patients from patients in DSC‘s caused by either withdrawal states after abuse of alcohol or barbiturates, or psychogenic psychoses. Reliable and discriminating symptoms were found. However, different symptoms discriminated when patients in different diagnostic groups were compared. Three kinds of discriminating values of a symptom may be distinguished from one another: 1) only the presence of a symptom is informative; 2) only its absence is informative; 3) both presence and absence of the symptom are informative.

-

Key words. Consciousness disorders - delirium organic psychoses differential diagnosis - schizophrenia - dementia - reliability.

- psychopathology

-

Throughout the present century the concept of “disturbed state of consciousness” (DSC) has been fundamental in continental psychiatry. T h e concept is still considered fundamental, primarily for the practical reason that DSC‘s of more than slight degree usually have relatively acute - and often treatable - physical causes. DSC’s include roughly delirious states, clouding of consciousness, acute and subacute organic confusional states, and ‘‘lowering of consciousness” if this lowering is not a non-pathological sleepiness or sleep. Epileptic and hysterical fugues are also DSC‘s. However, uncomplicated chronic demented states are not included. Elsewhere A g g e r n m (1975) attempts to clarify and

52 define the concept of DSC. In the present paper, we attempt to elucidate the concept on the practical clinical level. A list of 21 “objective” symptoms of DSC‘s, compiled from the literature, is presented. Then our use of this list in investigations of 105 patients is reported. Finally we attempt, on the basis of our results, to formulate testable hypotheses concerning the following problems:

1. May disturbed states of consciousness (DSC’s) be differentiated reliably from clear states of coqsciousness (CSC‘s) by experienced clinicians? 2. May the number of “objective” symptoms of DSC‘s (out of 21) be used reliably to differentiate particular kinds of DSC‘s from particular kinds of CSC‘s? 3. Which symptoms of DSC’s occur most frequently in different kinds of DSC‘s? 4. Which symptoms of DSC’s are best to differentiate between particular kinds of DSC‘s and CSC‘s? 5. Which symptoms of DSC’s may be recorded with the highest reliability in different clinical states?

The DSC scheme

To construct a list of symptoms, which had been claimed to be important in DSC‘s, Aggernaes reviewed the following literature: Bleuler (1966), Bleuler et al. (1966), Bonhoeffer (1901), Bonhoeffer (1912), Conrad (1960), Engel & Romano (1959), EwaZd (1928), Ey (1954), Hartrnann & Schilder (1924), Heimann (1963), Jaspers (1956), Lipowski (1967), Ludwig (1966), Schneider (1967), Shor (1959), Stromgren (1945), Taylor (1966), Victor & Adarns (1962), Wieck (1956), Wieck & PhiZipps (1965), and Winthers & Hinton (1971). The scheme given below was constructed by taking together under each heading symptoms which were very similar to one another. Furthermore, symptoms which in the literature were very vaguely defined or described were not included, because it was felt highly improbable that such symptoms might be judged reliably. However, since most of these poorly described symptoms “have something to do with” one or more of the clearly defined symptoms, the scheme presented below does to some degree “cover” these symptoms. The 21 “objective” symptoms which we attempted to evaluate in each patient were the following: 9a. Orientation in time, inclusive of the day in the week and roughly the hour of the day. 9b. Orientation in place (at home, at the job, in an institution, in a hospital). 9c. Orientation in own standard data (birthday, age, job, home address). 9d. Orientation in own recent data. (Why and when brought to the hospital; special things which the patient might have experienced within the Iast few days, for instance complicated or uncomfortable medical examinations). 13. Sleepiness or drowsiness. Does the patient exhibit any of the following:

53 a sleepy expression on his face; sleepy facial movements; lack of spontaneous speech; latency in answers; drowsiness when left alone for a moment; sluggish, colorless experiential life; slow thinking; marked changes in the degree of wakefulness? 14. Global comprehension of his situation. Is the patient able to place in perspective his present situation in the hospital and other aspects of his life, such as his financial situation and his relation to family members? 15. Continuity and coherence. Does the patient demonstrate any of the following: incomplete words or sentences; strange discontinuities in thought content; discrepancies between what he says and does and what he expresses in his tone of voice, facial movements and gestures? 16. Concentration. Is it difficult for him to keep his attention on one subject; is he absent-minded; do his thoughts seem to be voluntarily ordered, steered, goal-directed - or do they often run astray? 17. Vague experiencing. Does he mix up items or situations; has he difficulties in describing his experiences; do idiosyncratic, affective, or ambiguous meanings of words and sentences disturb the logic and coherence of his understanding and use of language? 18. Perplexity. Does the patient show objective signs of feeling perplexed or irresolute, in his facial movements, gestures, expression, words, or acts? Is his tone of voice questioning or hesitating; does he sometimes look around bewildered? 19. Signs o f recognition of abnormality. Does the patient seem to feel mentally abnormal for the time being; are there indications that he feels troubled about not being able to concentrate and think clearly; does it appear as if he is struggling to “collect himself” in order to understand and answer questions? 20. Suggestibility. Is it easy to make the patient change his statements by using leading questions? 21. Quality o f contact with patient. Is the patient cooperative; or actively rejecting in his attitude; or indifferent; is he sometimes “far away”, absorbed by emotions; is the level of contact with him very variable? 22. Interest in the surroundings. Is the patient interested, in a normal way, in what goes on around him; or does he appear to be living in an inner fantasy world much of the time? 23. Differentiation o f facts from fantasies. a) correctly; b) in an unconventional, but clear way; c) uncertain, unclear differentiation. Are there confabulations, hallucinations, illusions, delusions, depersonalization, derealization, or misinterpretations? 24. Mood and affect. Is the patient’s affective life blunted; is he apathetic; do seemingly unmotivated shifts in mood appear; do mood and affect appear to have unusual effects on the rest of the patient’s experiential life? 25. Abnormalities in behavior. Does the patient demonstrate stereotypes in movements or sounds; restlessness in movements, talk, and behavior; is his behavior coordinated and appropriate to the situation; does his behavior indicate disregard for simple social norms? 4

ACTAPSYC 51:l

54

26. Memory f o r recent data. Is the patient able to remember or recognize matters from earlier in the (same) interview; does he sometimes forget questions before he has finished answering them? 27. Changes in state during the examination. I n principle, this is judged in terms of all the other variables, but especially in terms of sleepiness, concentration, vagueness, continuity, and reality testing. 28. Pervasiveness of disturbances. Is every experience abnormal in some way during the investigation, either concerning tone of feeling, continuity, clearness, uncertainty, misinterpretation, reality testing, tempo, or something else? 29. Perseveration. Is there perseveration in the patient’s speech or behavior? Coding. The coding of all variables was based on the investigator’s general clinical impression. If the patient was judged to be normal or nearly normal on a variable, the variable was coded Normal. If the patient was judged clearly abnormal on variable, it was coded Defective. If the patient could not be judged on a variable, the coding was Uncertain. Immediately after the filling in of the scheme the investigator gave a short description of the patient’s state of consciousness and classified this state as not disturbed, moderately disturbed, or severely disturbed. The 21 variables meqtioned are objective in the sense that they are meant for coding based on the investigator’s judgment of the patient’s state. In our actual work, we also used a subjective DSC scheme meant for codings concerning the patient’s own conception of his mental state during the examination and the few hours immediately preceding the examination. This subjective DSC scheme comprised eight variables: 1) concentration; 2) ability to direct own thoughts; 3) alertness; 4) perplexity; 5 ) memory; 6) global comprehension of situation; 7) clarity of thoughts; 8) ability to differentiate fact from fantasy. These eight variables were coded on the basis of the patient’s answers to specified questions concerning the variables. These variables were coded “normal”, “defective”, or “uncertain”, depending on whether the patient found himself to be normal or abnormal concerning the variables - or was in doubt. The patients’ answers to our questions concerning these variables (1-8) have no doubt influenced both our general impression of the patients and the codings on the variables 9 a - 29 in the “objective” part of the DSC scheme described earlier. However, for two reasons the variables 1-8 are left out in the quantitative computations to be presented later in this paper. First, the results seemed to discriminate between different diagnostic groups rather poorly, probably because different patients had very different “tolerance limits” concerning abnormalities in their own experiential life. Second, the codings normal and defective are ambiguous in these eight variables: The coding normal indicates normality if the variable in question actually is normal. If the patient finds his memory normal, this is not pathological if he actually exhibits no memory defects. But if the investigator finds severe defects in the patient’s memory, then a normal code would indicate pathology, namely a lack of insight into own psychological defects. In the same way, the coding defective may indicate a relative normality: insight into his illness; or it may indicate pathology: unreasonable feelings of insufficiency. In the concrete investigation situations, it was left to each investigator to decide how to structure his communication with the patient in order to obtain sufficient information to code the 21 “objective” DSC-variables. Before we started the investigations to be presented, we used only a few hours to

55 make sure that we agreed with each other approximately upon the meanings of the 21 variables. Furthermore, we examined a few “pilot” patients together.

Design of the study The present study was performed with patients who at the same time participated in a study of experienced reality in different categories of psychiatric patients. For the reality testing study, it was important to make sure whether the patients were in disturbed states of consciousness (DSC‘s) or in clear states of consciousness (CSC’s). Concerning five groups of patients, such an assurance was obtained by means of two investigators agreeing on each patient as to whether the patient was in a DSC or in a CSC. The selection procedure and criteria were as follows: Two groups were somatically ill patients, who had been hospitalized in an acute internal medical ward less than 24 hours before. Only patients more than 65 years old who were neither aphasic, deaf, nor tormented by severe pain nor severe difficulties in breathing, were included. Aggernaes (AA) selected among such patients subjects for groups 1 and 2, using the following criteria: G r o u p 1 . These patients were to be classified as being in DSC’s as far as could be judged from 5-10 minutes of interviewing. I n these “selection interviews”, the greatest importance was attached to the variables 9a, 9b, 9d, 13, 15, 16, 17, 18, and 26 in the presented DSC scheme. The variables 9d and 26 deserve some elaboration. Variable 9d, orientation in own recent data, could nearly always be evaluated through the question, “When did you arrive at the hospital?” The patients had been hospitalized less than 24 hours before our first investigation. Demented CSC patients knew this, while DSC patients never knew this with any precision. The principle in questioning about this variable is to know some important event in the patient’s recent life, and to find out his orientation concerning this event. This variable is related to, but not identical with variable 26, memory for recent data. To evaluate this latter variable, both more and less important events are evaluated. During the selection of patients to be included in the study AA often left the patients and came back again. This led to the following technique: After having talked 3-5 minutes with a patient about his present state, the investigator left the patient alone for 5-15 minutes. In returning to the patient the investigator said, “Haven’t we met before?” Demented CSC patients could always recognize the investigator, and they also knew that they had met him the same morning. DSC patients either did not recognize the investigator; or they said (politely) yes, but could not indicate the time for the earlier meeting. A usual answer here was, “Some days ago”, or “During my last hospitalization”. It is AA‘s clear impression that this technique gave very valuable information - even though it cannot be documented with figures. As a later recorded amnesia for a given interval of time is, in the literature, taken to be a strong indication of a DSC - then it is also natural to suppose that the above technique used during the DSC may give important diagnostic information. G r o u p 2 . These patients were to be classified as being in CSC’s when evaluated in the same way as the patients in Group 1. Furthermore, these patients 4*

56

were to be moderately or severely demented, as described in Aggernm & Myschetzky (1975). Immediately after the selection, the first six patients in each of the groups 1 and 2 were examined simultaneously by Myschetzky (AM) and AA to obtain specified evaluations of their reality testing and to obtain codings on the variables of the DSC scheme. Concerning these 12 patients (six in DSC‘s and six in demented CSC‘s), our estimates were given blindly, i. e., without knowledge of the other investigator’s estimates. The following nine patients in each of the groups 1 and 2 were (after the selection interviews) examined first by AM alone and later by AA. Concerning these patients, AA knew whether AM had found them in DSC‘s or in CSe‘s, but did not know AM’S codings on the variables 9a through 29. Patients for the groups 3, 4, and 5 were selected by AA in psychiatric d e partments, using the following criteria: Group 3. These patients were to be classified as schizophrenic with a duration of illness of less than 3 years, or they were to be in states which could be diagnosed as “schizophrenic reactions” or as “schizophreniform psychoses” (Langfeldt (1956, 1969), Stromgren (1965), and Welner & Stromgren (1958)). Group 4. These patients were selected as being in DSC‘s, as evaluated primarily through the variables mentioned in relation to group 1. Only patients less than 65 years old were included. Group 5. This group consisted of patients who were clearly non-psychotic at the time of our investigations of them. The first five patients in each of the groups 3, 4 and 5 were evaluated simultaneously by AA and one co-examiner (either Paikin (HP) or Vitger (JV)) on the basis of interviews conducted by either AA or the co-examiner - alternating from one patient to the next one. The last ten patients in each group were examined first by AA alone and later by HP or JV. The global estimates: DSC versus CSC were not done in a “blind” way in groups 3, 4 and 5 , as the co-examiners as a rule knew whether AA had found these patients in DSC‘s or in CSC‘s. However, they did not know which of the 21 DSC scheme variables AA had judged as being defective. One further group was examined by AA without control of reliability: Group 6. This group included schizophrenic patients with a duration of illness of 3 years or more.

MATERIALS Details concerning five of the six patient groups are presented elsewhere (Aggern m & Myschetzky (1975) ad groups 1 and 2, Aggernm, Paikin & Vitger (1975) ad groups 3 and 6, Aggernres, Haugsted, Myschetzky, Paikin & Vitger (1975) ad group 5). The most important background data are the following: Group 1. (DSC patients more than 65 years old). The DSC’s in all 15 patients were caused by somatic states like dehydration, cerebral hypoxaemia or sequelae to this, febrile states, diabetic praecoma, and uraemia. Six were females, nine males. Age. Range: 66-90 years. Mean: 76.6 years. Group 2 (demented patients more than 65 years old, in CSC‘s). One patient

57 exhibited few but unquestionable signs of dementia. In nine patients, many signs of dementia were conspicuous even in a brief interview. This was also the case in the remaining five patients with severe dementia, defined as dementia which caused marked problems for the patient or his relatives in everyday life. Eight patients in this group were females, seven men. Age. Range: 66-85 years. Mean: 75.4 years. Group 3 (acute schizophrenics). Three patients were females, 12 males. Age. Range: 17-37 years. Mean: 24.2 years. Duration of illness in months. Range: 9-32. Mean: 22. Group 4 (DSC patients less than 65 years old, in psychiatric wards). Six patients were females, nine males. Age. Range: 27-59 years. Mean: 45.8 years. Thirteen out of these 15 patients had either delirium tremens or psychotic withdrawal states after abuse of barbiturates or meprobamate. The case histories of the remaining two patients were as follows: Case no. 8, a 27-year-old woman was hospitalized in a DSC which lasted 2 weeks. After that she cleared up completely to a non-psychotic state. The anamnesis was obtained from various sources, but no physical cause could be found or suspected. However, she had had rather severe psychological traumas during the latest weeks before the hospitalization. Case no. 2, a 36-year-old man was during his first week of hospitalization in a very fluctuating state of consciousness, sometimes clearly disturbed. At our investigation .both coders found him in a mild DSC. The later course of his illness has included a typical endgoneous depression, and his state at the time of our investigation was probably a severe atypical mania with intermittent DSC. Group 5 (nbn-psychotic patients in psychiatric wards). Seven patients were females, eight males. Age. Range: 24-64 years. Mean: 43.7 years. Most of these patients had personality disorders. Group 6 (chronic schizophrenics in CSC's). These 30 patients had all been psychotic with schizophrenia-like symptoms and courses during periods of 3 years or more. Eight were females, 22 males. Age. Range: 22-62 years. Mean: 38.0 years. Duration of illness. Range: 3-38 years. Mean: 10.5 years.

RESULTS In the following five paragraphs the results are presented in different ways which relate them to the five problems mentioned in the introduction.

1. The reliability of global estimates of whether a state is a DSC or a CSC

As it was decided beforehand to have 15 patients in each of the first five groups on whom two investigators agreed concerning the global variable DSC versus CSC, the fact that we succeeded in finding five times 15 patients does not mean that the reliability was 100 %. The lack of reliability and the dEgree of the lack was reflected in the number of patients, where we disagreed on the

58

variable and where the patients were excluded from the investigation on our way to finding the five times 15 patients on whom we did agree. On our way to finding the 30 patients for groups 1 and 2, we only excluded one patient on whom we disagreed. This result must be considered against the background that many of the DSC‘s were mild DSC‘s and that most of the demented patients were very demented. The 45 patients for groups 3, 4, and 5 were found without exclusion of any patient on whom we disagreed. All examined patients in groups 3, acute schizophrenics, and 5, non-psychotics, were found to be in CSC‘s by two investigators. Even though many of these estimates were not made without knowledge of the other investigator’s estimates, these results indicate that trained examiners can differentiate DSC‘s from CSC‘s in a reliable way, at any rate if their global estimates are made after having evaluated each of the 21 variables in the DSC scheme.

2 . Numbers o f “defective” codings on the DSC scheme variables in different diagnostic groups

Even though our estimates DSC versus CSC were not based on the use of the DSC scheme as a rating scale, the numbers of “defective” codings might be expected to be markedly different in the different diagnostic groups. In Table l‘it can be seen that no investigator found less than nine “defective” codings in any of the 30 patients in the two groups of DSC patients. This result differentiates the DSC patients completely from the demented CSC patients, as no examiner found more than eight “defective” codings in any of these patients. The results in Table 1 concerning acute schizophrenic patients and psychiatric inpatients in DSC‘s do not differentiate these groups from each other in the same clear-cut way.

Table 1. Numbers of ”defective“ codings ost of 21 possible in I5 patients in each of five different diagnostic groups

Nos. of defective codings per patient (Range) Diagnostic groups

Coder

AA

Co-examiner AM, HP or JV

59 Table 2. Numbers of defective codings on each of the 21 “objective” variables in each of the examitzed patient groups

Nos. of defective codings, out of 15, in demented patients more than 65 years old

Coder

9a 9b 9c 9d 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

* ** ***

7 1 1 3 1 1 0 2 1 2 1 3 0 0 0 5 0

14 1 0 9

12 2 0 1 I* 4 1 4 0 1 0 1

O* 1* 3 4*

o* 8*

2 2* 8

15, in DSC‘s in patients

I

> 65 years < 65 years

I

Coder

15 11 8 15 11 15 7 14 13 10 4 10 4 5 15 8

4 15 13 13* 10

15 10

I

Coder

12 12* 10 8* 8 3 5* 15 13 12* 7* 10 11 12 15 14* 7 1 2 1 4 10 14 15 12 15 15 8 10 14 2 7 7 8* 8 12* 3* 9 13* 13* 6 13 15 13 15 14 7 12 o* 12 11* 11* 15 15 14 13* 15 13* 7 14 14 9* 7

15, in acute “schizophrenics”

15, in

30, in chronic

Coder

Coder

Coder

I

4 1 0 4 1 3* 5 4 5 3 1 1 8

7 12 9 2 2 3 1 1

5

1* O* 4 1 2* 4 6 4* 4*

3 1* 7 3** 8*

9 3* 2* 3 1***

4

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 5

0 0 0

1 0 0 1 0 1* 0 0 0 0 0 0 0

o*

0 1 0 0 0 0 0

5 0 0 2 0 8 12 7 18 4 3 0 21 18 28 27 6 0

2 0 9

Here, one, two or, in a single case, three patients out of the 15 had the code: Uncertain. Six patients out of the 15 had the code: Uncertain. Four patients out of the 15 had the code: Uncertain.

3. T h e variables which are most frequently defective in all examined DSC‘s In the compilatory Table 2 it can be seen that the following seven variables were defective in at least 80 % of the patients in each of the two DSC groups and for both AA and the co-examiners: Variables

9a - Orientation in time. 9d - Orientation in own recent (important) data.

60 14 - Ability to place in perspective one’s actual situation. 17 - Vague experiencing.

23 - Reality testing. 26 - Memory for recent data. 27 - Changeability of the patient’s state during the examination.

In 14 out of the 30 DSC patients, all of these seven variables were coded defective by both coders. In none of the DSC patients, were less than five of these variables coded defective by any coder. That these seven variables were rather constantly and reliably coded defective in DSC’s, does not necessarily imply that they, in any clinical case, are the most valuable for differential diagnosis. It would be of theoretical importance, however, to examine in other and larger patient materials whether these seven variables are so constantly defective in DSC‘s as is indicated by the present study.

4. Which variables in the DSC scheme are the most valuable ones in relation to particular differential diagnoses? We will now use our results as a basis for stating some hypotheses concerning the differential psefulness of the 21 “objective” variables in the DSC scheme. More concretely, we will treat two kinds of situations: First, the patient is more than 65 years old and recently acutely hospitalized in a somatic dzpartment. IS he in a DSC or in a demented CSC? Second, the patient is less than 65 years old and hospitalized in a psychiatric department. Is he in a DSC or in an acute schizophrenic state? In principle, a variable may have diagnostic value in three ways: a. A defective code may indicate the DSC, a normal code the CSC. In our computation we have arbitrarily said that this is the case if 80 % or more defective codes are given by both investigators on the variable in the DSC patients, and 80 % or more normal codes are given by both investigators on the variable in the relevant CSC patients.

In our material, 80 % nearly always means 12 out of 15. In a few variables, see Table 2, a few of the patients were coded “uncertain”. Then the per cent has been computed as per cent of defective codes (normal codes, respectively) out of the sum of defective and normal codes given. b. A defective code may indicate the DSC, while a normal code is of no diagnostic value. This is the case if the variable is practically always found normal in CSC’s, while it sometimes is found defective in DSC’s. To find variables which discriminate in this way, it is nxessary to convert the words “practically always” and “sometimes” to statistical values. In the construction of our Table 3 from the results in Table 2 we have arbitrarily chosen that “practically always” means that both investigators in at least 90 % (usually 14 or 15 out of

61 Table 3. The most valuable variables from the “objective” part of the DSC scheme for some differential diagnoses Differential diagnosis

Diagnostic value

a. Defective and normal codes differentiate (P 0.80) b. Defective codes indicate DSC‘s (P 0.90) c. Normal codes indicate CSC‘s (P 0.90)

In somatic patients more than 65 years old

In psychiatric patients less than 65 years old

Variable nos.

Variable nos.

>

9d, 17, 23, 27

26, 27, 28

>

9c, 13, 15, 22

9b, 13, 20

>

9a

14, 16, 17

15) of the CSC patients found the variable normal. The word “sometimes” is in the same way translated to mean that both investigators in at least 30 % of the DSC patients found the variable defective. c. A normal code may indicate the CSC, while a defective code is of no diagnostic value. This is the case if the variable is practically always found defective in DSC’s, while it is sometimes found normal in CSC‘s. Like in b. above, “practically always” means in at least 90 % of the patients, and “sometimes” means in at least 30 % of the patients. Table 3 presents the variables which discriminate in the ways a, b, and c. The hypothetical nature of this table must be emphasized, because it is constructed on the basis of a rather small number of patients. Nevertheless, we find it of value to present for two reasons. It is based on results checked as to intertester reliability, and it illustrates a point which is a banality - but still too seldom taken into account in psychiatric clinical research and textbooks - namely the point: In a given psychiatric syndrome, different symptoms may be characteristic or essential when different differential diagnoses are the relevant ones. Even if future research results in some modifications of the hypotheses reflected in Table 3, it will probably remain true that in diagnosing a DSC, different symptoms are important when the relevant differential diagnosis is a CSC in a demented patient, and when the differential diagnosis is a CSC in a schizophrenic patient. Finally, research along the lines sketched above is of value both for routine clinical work and for the more elaborated statistical diagnostic systems which Mellergdrd & Leroy (1973)and Leroy & Mellergird (1973)aim at.

62

5. The point by point reliability of the variables The agreement between different evaluators in the results in Table 1 and in Table 3 could have been obtained even though the point by point reliability was poor on each of the variables 9a-29. T o illustrate: Ad Table 1 . Two evaluators could both report nine out of 21 variables defective in a given patient, and yet have coded 18 of the 21 variables differently. Ad Table 3. Two evaluators could both find 12 out of 15 DSC patients with defective codes on a single variable, and yet have coded six of the 15 patients differently on this variable.

The point by goint reliability presented in Table 4 is of interest, especially in case inclusion of some of the variables in a rating scale should be desired. Furthermore, Table 4 can give some guidance where in a particular kind of research, only a few but highly reliable variables should be required. Finally, the table indicates that the point by point reliability of many of the variables was not impressive. Table 4. The codability and the point by point reliability of the DSC scheme in different patient groups

I Patient groups

I

1’ 1 Coder

Codings which were not uncertain

1

- and

Agreement point by point between A A and co-

of the “objective” part specified on the variables 9a-29

Variables agreed on in the specified percentages

I I

100% 99-87%

I

8667%

ILes thm

67%

100 97

86

13 21 25

9b, 9c, 15, 17, 19, 22 27, 9d

All but

-

26

AM

DSCs in patients more than 65 years

AA Ah4

99 97

78

9a 9d 26

27 19 23

All but

28, 29 20, 15 16

DSC‘s in patients less than 65 years

AA HP or JV

9d 14 17 23

16 27 28 26

Suspected acute schizophrenics

AA HP or JV

99 93

81

9b 9c 9d 13 28

20 22 27

All but

-

21 24

Nonpsychotic patients

AA HP or JV

100 99

97

9a 9d 14 24

26

None

Demented csc‘s

AA

100 96

81

All but

cf

All but

20 29

Cf

63 Discussion of the point by point reliability

The 21 variables were not strictly operational. One could therefore suspect that the most abstract of our variables were the least reliable ones. We have not been able to classify our variables on a continuum from more to less abstract, but the results in Table 4 are also to some degree incompatible with such an explanation, because it is different variables which are most reliable in the different kinds of clinical states! In the demented group and in the DSC groups, it was our impression that reliability problems were to a large degree based on difficulties in deciding whether very slight or doubtful abnormalities should be coded defective or normal. In the schizophrenic group, problems arose if there was a deviation on the variable, but a deviation of another kind than the one usually seen in DSC‘s. If these impressions are correct, then better reliability could be obtained through further specification of the variables and the signs indicating defects in each of them - and maybe through a more differentiated coding system, for instance: Normal = 0. Maybe defective = 1. Absolutely, but slightly defective = 2. Moderately defective = 3. Severely defective = 4. At any rate, such a coding system would be needed if a rating scale for degrees of DSC should be constructed. For even though our results in Table 1 indicated a marked and reliable differentiation on the dichotomy DSC versus CSC, the correlation between two evaluators within the DSC groups was not SO pronounced that “number of defective codings” would be a reasonable measure of the degree of DSC. Thirty chronic schizophrenics

At the time for the investigation of these patients, 21 of them were in phases of exacerbation of the schizophrenic symptoms. The results concerning the DSC scheme variables 9a-29 in these 3 0 patients can be found in Table 2. It is conspicuous that the resufts are very simifar to the results in the 15 acute schizophrenic patients. It is of special interest to note this similarity concerning the variables in Table 3 which differentiated acute schizophrenic states from DSC‘s. For this result gives some indirect support to the hypothesis that the variables in the last column in Table 3 really are discriminating. In relation to Table 1, it is of interest that the chronic schizophrenics had the following numbers of defective variables out of 21 possible ones: Twenty-seven patients had 0-9 defective codings; three patients had 11, 12, and 13 defective codings, respectively. This is also of the same order of magnitude as in the acute schizophrenics. DISCUSSION In modern psychiatry and clinical psychology, scepticism is often expressed concerning both our diagnostic system and the classical descriptive psychopathological concepts.

64

The results presented in the present paper are not impressive, but they still seem to give some support to the point of view that it is possible to perform clinical psychiatric work in a rather reliable way. Yet many of the variables studied clearly need further clarification to become still more reliable. And clarification is needed both concerning our concepts and concerning our investigational technique. Use of rating scales (Wirtenborn (1972)) may raise the reliability of our techniques. But it cannot be emphasized too much that high reliability is of no use to our patients if problems of validity are not taken still more seriously. Our results indicate that it is possible to use the concepts of disturbed and clear states of consciousness in a rather reliable way. But is it valid? What does validity mean in this connection? In one sense our results are valid: They can be used in differentiating clinical states which need different treatment. A more thorough treatment of the important validity problem, however, presupposes a clear definition of the concept: disturbed state of consciousness. An attempt to develop such a definition is made in Aggernres (1975).

CONCLUSION As the concept disturbed state of consciousness is highly important in clinical work, an attempt is made to evaluate whether it can be used in a reliable way by experienced clinkians. In the present research this seems to be the case, but only a part of our research was done with a strictly “blind” technique. For educational purposes, it is important to evaluate a number of commonly recognized symptoms of disturbed states of consciousness - as to their value in differential diagnosis. We have evaluated 21 such symptoms or variables as to reliability and discriminative value. The results indicate that it is possible to localize reliable and discriminating variables - even though our patient materials were so small (15 patients in each of five groups) that our concrete results need confirmation in other studies. However, we feel safe in drawing the following conclusions: In judging a state as a disturbed versus a clear state of consciousness, different clinical symptoms or variables are the relevant ones when different differential diagnoses are the relevant ones. In searching for discriminating clinical variables it is important to recognize that variables may be valuable in three different ways: 1) a variable may discriminate “both ways”, its presence indicates one state, its absence another state; 2) the presence of the variable may indicate one state, while the absence of it is diagnostically non-informative; 3) the absence of the variable may indicate “the other” state, while the presence of the variable is diagnostically noninformative. ACKNOWLEDGMENTS

This research was only possible by virtue of the kind cooperation of the personnel in the following departments: Rigshospitalet, Psychiatric Department 0, (Heads: V . Lunn, 0. Rafaelsen, T. Vanggaard). Bispebjerg Hospital, Psychiatric Department E, (Head:

65 A . Myschetzky). Bispebjerg Hospital, Departments S, B, C, N, P and T, (Heads: J. Lyngsoe, M . Bjorneboe, N . B. Krarup, E . Skinhoj, K . N . Rasmussen and J . Pedersen). Thanks are extended to R . Shapiro, M.D., for help with the formulation of the manuscript into readable English, and for important advice concerning the structure of the paper.

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Anton Aggernes, M.D., Ph.D. Department H St. Hans Hospital 4000 Roskilde Denmark