J Clin EpidemiolVol. 44, No. 2, PP. 207-209, 1991 Printed in Great Britain. All rights reserved
0895-4356/9153.00+ 0.00 Copyright 0 1991Pergamon Press plc
Second Thoughts THE NUMBERS
GAME
JOSEPH HERMAN Department of Family Medicine, Faculty of the Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (Received in
revisedform 30 July 1990)
It has been suggested that medicine is in retreat from the realities of the clinical hunch and the well-managed interview to “. . . the high ground of laboratory proven, reductionistic bioscience” [l]. Mensuration has grown so pervasive in everyday practice as to erode what little freedom is left in our free profession. Whereas, in the past, a physician could have chosen not to know the patient’s blood sugar if it did not seem relevant to the chief complaint, today’s technology forces him to consider it even if signs and symptoms point elsewhere. Probability has conferred scientific respectability on medical research and appears to have put paid to the nagging doubts arising from Sir William Osler’s celebrated aphorism: “It is much more important to know what sort of patient has a disease than what sort of disease a patient has” [2]. We are in possession of many more “facts” than Sir William had at his disposal and we have become adept at making them say what we want. Indeed, the quantitative difference between then and now is so great that it has almost become qualitative. We must make certain that the high ground does not become a refuge where “minds innocent and quiet” can shelter from the orneriness of the clinical encounter and the recalcitrance of the patient whose illness does not go by the book. Some years ago a colleague told me of the following, unusual chain of events. He referred a patient to an ophthalmologist who reported that the eyegrounds were definitely diabetic. The patient, however, had always been normoglycemic and, on repeated testing in the light of CE 44,2--H
207
the oculist’s findings, still was. There was no family history of diabetes and the results of an oral glucose tolerance test were within normal limits. My colleagues regretfully concluded that his consultant was not up to standard and was seriously considering a change. The pressure of a busy practice diverted him for a time from his resolve and, one day about six months later, the same patient came in with a full-blown clinical picture of diabetes mellitus. Those among us who are a bit better read pay lip service to their understanding that diabetes is a multi-system disease involving, among other organs, the pancreas and that hyperglycemia, variously defined, is but one manifestation. On the other hand, we have elevated the finding of a fasting blood sugar of 140 mg/dl on two separate occasions to the status of a sufficient condition for diagnosis [3]. Thus, an element of intellectual confusion has been introduced into diabetology and we are left with the absurd state of affairs in which the difference between glycemias of 139 and 141 mg/dl is one of being diseased or not. Our attitude towards treatment also suggests that we enjoy playing a kind of numbers game, battling with our asymptomatic patients over their blood sugars as though hyperglycemia were what was wrong with them! What would happen to the sensitivities, specificities, positive and negative predictive values of elevated levels of glucose and cholesterol if some august international body were to lay down definitions of diabetes and hyperlipidemia on clinical grounds only? How comfortable would we feel practising medicine
208
Second Thoughts
today were mensuration relegated to the subsidiary position of arbitrating cases where uncertainty prevails? I have chosen the word with care because it also “mensuration” applies to taking a patient’s blood pressure which produces another number that can be “treated”. Two recently published articles underscore the difficulties involved in taking a measurement as distinct from making an observation in the course of the history and the physical examination. The first deals with the carpal tunnel syndrome and examines the predictive values of certain well-known maneuvers such as twopoint discrimination, Tinel’s and Phalen’s tests and of anamnestic elements expressed by the patient indicating affected areas on a hand diagram [4]. Tinel’s sign was elicited by dropping the head of a reflex hammer from a height of 12 cm onto the area under which the median nerve passes. One wonders how the results would have changed had 11 or 13 cm been chosen and if a gold standard with a sensitivity above 90% were available. It is also interesting to note that the figure of 10% false negatives for the electromyogram was derived by operating on certain subjects “in defiance” of normal nerve conduction [4]. Such a practice amounts to retroactively grading a sophisticated procedure in the light of clinical findings. These latter, in the instance under consideration, might be the surgeon’s impression of the appearance of the median nerve or the patient’s appreciation of the results of the intervention. Thus, consciously or not, we are basing sensitivity calculations on clinical judgment. Hypertension, a more prevalent condition, is discussed in a second paper [5]. The authors meticulously studied 15 patients apparently resistant to therapy and encountered two phenomena that would lead to a person’s being wrongly classified as having high blood pressure. One, long known but of growing significance because it applies particularly to the elderly, has to do with hardened arteries that give a falsely high reading. The second, which they refer to as “cuff-induced” hypertension, was found in young people too and was demonstrated by comparing an intra-arterial determination in one arm with a sphyngmomanometer measurement in the other. When the cuff was inflated, the brachial artery pressure also rose, whereas it was otherwise normal [5]. Are human beings measurable in any sense at all? Kleinman has pointed out there is no
metric in bio-medical and behavioural research for the existential qualities of suffering-hurt, desperation, moral pain and triumph [6]. These are best evaluated by ethnography, biography, history and psychotherapy and the thinned-out image of patients and families arising from symptom scales and survey questionnaires may be, as he says, scientifically replicable but ontologically invalid. They have statistical, not epistemological significance [6]. The numbers associated with risk can be meaningless to the individual because the disease under consideration is an all-or-none process. Even if the cigarette a person is presently enjoying puts him into a high risk category for lung cancer or coronary artery disease, at this paricular moment he feels well. Should the danger materialize, he immediately becomes 100% ill and there are no intervening percentages. Regarding human mensurability, a cynic would recall the high school life science books of half a century ago that estimated a man’s worth at less than a dollar in basic elements and compounds! Surely, to the extent that it is a science, medicine belongs to the Geisteswissenschaften where the objects of study are not general laws but the singular events that comprise personhood. According to Wilhelm Windelband, a German philosopher who was a contemporary of Freud, the truest method of such a “science of the spirit” should be history rather than mathematical analysis since it deals with what can neither be replicated nor predicted [7]. Thus, the uniqueness and one-timeness of the higher animals with their elaborate brains imprinted by instinct and experience may spell trouble for the quantitative conclusions we draw from experimentation. A model of proactive, as opposed to reactive, primary care has been mooted recently [8]. The underlying assumption would seem to be that such care is more egalitarian, circumventing as it does the low expectations of health services generally held by the poor. Proactive care means outreach and educating our patients to demand prevention rather than waiting for them to come in when many of them are too downtrodden and pessimistic to do so. This is all very well and it certainly assures that general practitioners, few of whom complain of underload, will be kept busy for the next century [8] but, unfortunately, it rests heavily on mensuration. Among the common conditions for which proactive care will be proposed are hyperlipidemia, hypertension, diabetes, glaucoma, chronic obstructive
Second Thoughts
lung disease and, possibly, osteoporosis. Most of them will occur in asymptomatic patients so that we shall. be following up and, worse, treating a number, not a person. Thus, the cat-chasing-its-tail logic inherent in setting up not so golden diagnostic standards and then determining their sensitivities by disregarding them [4] may prove expensive when it comes to examining proactive outcomes. What will be the cost in unnecessary therapy and the experiencing of the lived world through a haze of chemically manipulated sensory input in order to prevent strokes? The vast majority of stroke patients are not hypertensive and most people with high blood pressure do not incur a cerebrovascular accident [9]. Cuffinduced hypertension certainly suggests that we are treating some persons who are not only asymptomatic but actually well! These considerations put one in mind of the Unknown Citizen: “Was he free? Was he happy? The question is absurd: Had anything been wrong, we should certainly have heard.” [IO].
209 REFERENCES
1.
2. 3.
4.
5.
6. 7. 8. 9. 10.
Metcalfe DHH. The Edinburgh Declaration. Fam Pratt 1989; 6: 165-166. Quoted in Rake1 RE. Principies of Family Mediciw. Philadelphia, Pa: W. B. Saunders; 1977. Karam JH. Diabetes mellitus, hypoglycemia & lipoprotein disorders. In: Krupp MA, Schroeder SA, Tierney LM Jr, Eds. Current Medical Diagnosis and Treatment. Los Altos, Calif.: Appleton SCLange; 1987: 749-781. Katz JN, Larson MG, Sabra A et al. The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings. Ann Intern Med 1990: 112: 321-327. Mejia AD, Egan BM, Schork NJ et al. Artefacts in measurement of blood pressure and lack of target organ involvement in the assessment of patients with treatment-resistant hypertension. AM -Intern Med 1990: 112: 270-277. Kleinman A. The illness Narratives. New York: Basic Books; 1988. Bettelheim B. Reflections: Freud and the soul. The New Yorker 1982; 1 Mar.: 52-86. Tudor Hart J. Reactive and proactive care: a crisis. J R Coil Gen Pratt 1989; 40: 49. Alderman MH, Lamport B. Labelling of hypertensives: a review of the data. J Clin Epidemiol 1990; 43: 195-200. Auden WH. The Collected Poetry of W. H. Auden. New York: Random House; 1945: 142.
0895-4356/9153.00+ 0.00 Copyright 0 1991Pergamon Press plc
Second Thoughts THE NUMBERS
GAME
JOSEPH HERMAN Department of Family Medicine, Faculty of the Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (Received in
revisedform 30 July 1990)
It has been suggested that medicine is in retreat from the realities of the clinical hunch and the well-managed interview to “. . . the high ground of laboratory proven, reductionistic bioscience” [l]. Mensuration has grown so pervasive in everyday practice as to erode what little freedom is left in our free profession. Whereas, in the past, a physician could have chosen not to know the patient’s blood sugar if it did not seem relevant to the chief complaint, today’s technology forces him to consider it even if signs and symptoms point elsewhere. Probability has conferred scientific respectability on medical research and appears to have put paid to the nagging doubts arising from Sir William Osler’s celebrated aphorism: “It is much more important to know what sort of patient has a disease than what sort of disease a patient has” [2]. We are in possession of many more “facts” than Sir William had at his disposal and we have become adept at making them say what we want. Indeed, the quantitative difference between then and now is so great that it has almost become qualitative. We must make certain that the high ground does not become a refuge where “minds innocent and quiet” can shelter from the orneriness of the clinical encounter and the recalcitrance of the patient whose illness does not go by the book. Some years ago a colleague told me of the following, unusual chain of events. He referred a patient to an ophthalmologist who reported that the eyegrounds were definitely diabetic. The patient, however, had always been normoglycemic and, on repeated testing in the light of CE 44,2--H
207
the oculist’s findings, still was. There was no family history of diabetes and the results of an oral glucose tolerance test were within normal limits. My colleagues regretfully concluded that his consultant was not up to standard and was seriously considering a change. The pressure of a busy practice diverted him for a time from his resolve and, one day about six months later, the same patient came in with a full-blown clinical picture of diabetes mellitus. Those among us who are a bit better read pay lip service to their understanding that diabetes is a multi-system disease involving, among other organs, the pancreas and that hyperglycemia, variously defined, is but one manifestation. On the other hand, we have elevated the finding of a fasting blood sugar of 140 mg/dl on two separate occasions to the status of a sufficient condition for diagnosis [3]. Thus, an element of intellectual confusion has been introduced into diabetology and we are left with the absurd state of affairs in which the difference between glycemias of 139 and 141 mg/dl is one of being diseased or not. Our attitude towards treatment also suggests that we enjoy playing a kind of numbers game, battling with our asymptomatic patients over their blood sugars as though hyperglycemia were what was wrong with them! What would happen to the sensitivities, specificities, positive and negative predictive values of elevated levels of glucose and cholesterol if some august international body were to lay down definitions of diabetes and hyperlipidemia on clinical grounds only? How comfortable would we feel practising medicine
208
Second Thoughts
today were mensuration relegated to the subsidiary position of arbitrating cases where uncertainty prevails? I have chosen the word with care because it also “mensuration” applies to taking a patient’s blood pressure which produces another number that can be “treated”. Two recently published articles underscore the difficulties involved in taking a measurement as distinct from making an observation in the course of the history and the physical examination. The first deals with the carpal tunnel syndrome and examines the predictive values of certain well-known maneuvers such as twopoint discrimination, Tinel’s and Phalen’s tests and of anamnestic elements expressed by the patient indicating affected areas on a hand diagram [4]. Tinel’s sign was elicited by dropping the head of a reflex hammer from a height of 12 cm onto the area under which the median nerve passes. One wonders how the results would have changed had 11 or 13 cm been chosen and if a gold standard with a sensitivity above 90% were available. It is also interesting to note that the figure of 10% false negatives for the electromyogram was derived by operating on certain subjects “in defiance” of normal nerve conduction [4]. Such a practice amounts to retroactively grading a sophisticated procedure in the light of clinical findings. These latter, in the instance under consideration, might be the surgeon’s impression of the appearance of the median nerve or the patient’s appreciation of the results of the intervention. Thus, consciously or not, we are basing sensitivity calculations on clinical judgment. Hypertension, a more prevalent condition, is discussed in a second paper [5]. The authors meticulously studied 15 patients apparently resistant to therapy and encountered two phenomena that would lead to a person’s being wrongly classified as having high blood pressure. One, long known but of growing significance because it applies particularly to the elderly, has to do with hardened arteries that give a falsely high reading. The second, which they refer to as “cuff-induced” hypertension, was found in young people too and was demonstrated by comparing an intra-arterial determination in one arm with a sphyngmomanometer measurement in the other. When the cuff was inflated, the brachial artery pressure also rose, whereas it was otherwise normal [5]. Are human beings measurable in any sense at all? Kleinman has pointed out there is no
metric in bio-medical and behavioural research for the existential qualities of suffering-hurt, desperation, moral pain and triumph [6]. These are best evaluated by ethnography, biography, history and psychotherapy and the thinned-out image of patients and families arising from symptom scales and survey questionnaires may be, as he says, scientifically replicable but ontologically invalid. They have statistical, not epistemological significance [6]. The numbers associated with risk can be meaningless to the individual because the disease under consideration is an all-or-none process. Even if the cigarette a person is presently enjoying puts him into a high risk category for lung cancer or coronary artery disease, at this paricular moment he feels well. Should the danger materialize, he immediately becomes 100% ill and there are no intervening percentages. Regarding human mensurability, a cynic would recall the high school life science books of half a century ago that estimated a man’s worth at less than a dollar in basic elements and compounds! Surely, to the extent that it is a science, medicine belongs to the Geisteswissenschaften where the objects of study are not general laws but the singular events that comprise personhood. According to Wilhelm Windelband, a German philosopher who was a contemporary of Freud, the truest method of such a “science of the spirit” should be history rather than mathematical analysis since it deals with what can neither be replicated nor predicted [7]. Thus, the uniqueness and one-timeness of the higher animals with their elaborate brains imprinted by instinct and experience may spell trouble for the quantitative conclusions we draw from experimentation. A model of proactive, as opposed to reactive, primary care has been mooted recently [8]. The underlying assumption would seem to be that such care is more egalitarian, circumventing as it does the low expectations of health services generally held by the poor. Proactive care means outreach and educating our patients to demand prevention rather than waiting for them to come in when many of them are too downtrodden and pessimistic to do so. This is all very well and it certainly assures that general practitioners, few of whom complain of underload, will be kept busy for the next century [8] but, unfortunately, it rests heavily on mensuration. Among the common conditions for which proactive care will be proposed are hyperlipidemia, hypertension, diabetes, glaucoma, chronic obstructive
Second Thoughts
lung disease and, possibly, osteoporosis. Most of them will occur in asymptomatic patients so that we shall. be following up and, worse, treating a number, not a person. Thus, the cat-chasing-its-tail logic inherent in setting up not so golden diagnostic standards and then determining their sensitivities by disregarding them [4] may prove expensive when it comes to examining proactive outcomes. What will be the cost in unnecessary therapy and the experiencing of the lived world through a haze of chemically manipulated sensory input in order to prevent strokes? The vast majority of stroke patients are not hypertensive and most people with high blood pressure do not incur a cerebrovascular accident [9]. Cuffinduced hypertension certainly suggests that we are treating some persons who are not only asymptomatic but actually well! These considerations put one in mind of the Unknown Citizen: “Was he free? Was he happy? The question is absurd: Had anything been wrong, we should certainly have heard.” [IO].
209 REFERENCES
1.
2. 3.
4.
5.
6. 7. 8. 9. 10.
Metcalfe DHH. The Edinburgh Declaration. Fam Pratt 1989; 6: 165-166. Quoted in Rake1 RE. Principies of Family Mediciw. Philadelphia, Pa: W. B. Saunders; 1977. Karam JH. Diabetes mellitus, hypoglycemia & lipoprotein disorders. In: Krupp MA, Schroeder SA, Tierney LM Jr, Eds. Current Medical Diagnosis and Treatment. Los Altos, Calif.: Appleton SCLange; 1987: 749-781. Katz JN, Larson MG, Sabra A et al. The carpal tunnel syndrome: diagnostic utility of the history and physical examination findings. Ann Intern Med 1990: 112: 321-327. Mejia AD, Egan BM, Schork NJ et al. Artefacts in measurement of blood pressure and lack of target organ involvement in the assessment of patients with treatment-resistant hypertension. AM -Intern Med 1990: 112: 270-277. Kleinman A. The illness Narratives. New York: Basic Books; 1988. Bettelheim B. Reflections: Freud and the soul. The New Yorker 1982; 1 Mar.: 52-86. Tudor Hart J. Reactive and proactive care: a crisis. J R Coil Gen Pratt 1989; 40: 49. Alderman MH, Lamport B. Labelling of hypertensives: a review of the data. J Clin Epidemiol 1990; 43: 195-200. Auden WH. The Collected Poetry of W. H. Auden. New York: Random House; 1945: 142.
