- Email: [email protected]
Public survey of resource allocation preferences
184
Psychiatric diagnoses and diseases SIR,-Professor Szasz’s article (Dec 21/28, p 1574) is stimulating. one can take issue with his view of psychiatric diagnoses. Diagnoses are labels. As labels they provide us with a common language to describe events, and they allow us to differentiate and manipulate reality. Labels are only as useful as they are true: if they do not accurately represent the underlying reality they will not be very helpful. One can make two claims with respect to diagnoses as labels in psychiatric illness-first, that such illness is not well understood, so its labels are a poor representation of reality or, second, that psychiatric illness is a myth, that it has no reality, and therefore labels are meaningless. Much of medicine deals with poorly fitting labels, and it is not unexpected that psychiatry shares this difficulty. But Szasz seems to be taking the strong position that psychiatric illness is a myth, and that psychiatric diagnoses confer an appearance of reality where none exists. Almost all illness presents with changes in behaviour. A person with pneumonia coughs, breathes rapidly, is inactive, and complains of lack of interest in life. A person with depression loses weight, cannot sleep, is inactive, and complains of lack of interest in life. Both patients are dysfunctional, but how can their illnesses be differentiated? It avails them (and us) little if we say that we cannot separate these two patients because of our lack of understanding or because of the complexity of their diseases. Just because an illness is not well understood, or because it is very complex, does not negate its reality. Thus, we may need a higher level of analysis than brain synapses to understand depression, just as we need a higher level of analysis than atomic particles to understand cells. But our inability to explain cells by the activity of individual atoms does not mean that cells do not have a physical basis; it merely means that the physical basis of cells is very complex, and that certain simplifying assumptions can be made that allow us to reduce this complexity to a manageable level. Just because we cannot explain schizophrenia by neuronal processes does not mean that it is not a physical illness. To assert that there is a mental realm that is independent of the physical realm at work in psychiatric illness, and that this mental level is not amenable to psychiatric diagnosis, is to fall into the mind/body dualism trap-a trap from which no one has yet escaped. But
Department of Medicine, Medical College of Wisconsin, Milwaukee County Medical Complex, Milwaukee, Wisconsin 53226, USA
HARRY B. BURKE
SIR,-I enjoyed reading Professor Szasz’ article for its elegant style and stimulating arguments; unfortunately, his basic thesis is just as absurd now as it was twenty years ago when I read it as a medical student. Szasz seems to be being deliberately obtuse about what is meant by the term disease and is also remarkably coy about what he means by the notions of mind and free will. This would not matter too much if the debate were only among professionals: the real harm done by Szasz and his sympathisers is that they influence public policy when their views are picked up by the lay press, politicians, and others, and are used to justify grotesque notions such as that no one should remain in a long-stay psychiatric institution since the inmates of such establishments are not ill. Throughout history (and in all cultures) certain individuals have been recognised whose behaviour is so bizarre, so antisocial, so self-destructive (or a combination of all three) that it falls outside any sensible definition of normal. To anyone who has observed psychotic bahaviour at first hand it is inconceivable that such behaviour could arise from the exercise of free will; once demonic possession had been discarded as a likely cause the most attractive model became that of physical disease, especially when it became clear that certain forms of abnormal behaviour were indeed caused by organic diseases (thyrotoxicosis, epilepsy, tertiary syphilis). It is nonsense to argue that because mental illness is hard to define and to classify it does not exist--one could say exactly the same about love, jealousy, hatred, compassion, or a whole host of other emotional and mental states. Friarage Hospital, Northallerton, North Yorkshire DL6 1JG, UK
ROGER A. FISKEN
SIR,-Professor Szasz claims that "psychiatric diagnoses do not point to anatomical or physiological lesions and do not suggest causal agents, but allude only to human behaviours". In other words, human behaviours, when categorised by psychiatrists in diagnoses, cannot be the result of abnormal brain structure or function. Such a claim contradicts such a large number of studies that it was perhaps difficult for Szasz to choose even a representative sample to debunk, but I do not feel that this justifies omitting all reference to these studies. Every week The Lancet sensibly advises authors to assume that readers start from near-ignorance. Surely then authors, and editors, should ensure that ignorance is not exploited to lead readers into a partial viewpoint? Readers of Szasz’ article might not know of relevant reports or of claims that in some circumstances schizophrenia, a psychiatric diagnosis, points to structural abnormalities in the brain that can be seen on radiographs.’ However, perhaps Szasz’ argument is with diagnoses made by psychiatrists, in which case surely he should say whether neurological diagnoses are similarly misguided. What for instance does he think of the work of Professor Lhermitte, who finds that patients with inferior prefrontal lesions are at the mercy of environmental cues (eg, the sight of a tongue depressor led one woman to begin examining the professor’s throat)? Does Szasz think that this unusual human behaviour is unrelated to those brain lesions? Maudsley Hospital,
JONATHAN FLINT
London SE5 8AZ, UK
1. Suddath RL, Christison GW, Torrey EF, Casanova MF, Weinberger DR Anatomical abnormalities in the brains of monozygotic twins discordant for schizophrenia. N Engl J Med 1990; 322: 789-94. 2. Lhermitte F, Pillon B, Serdaru M. Human autonomy and the front lobes, I. Imitation and utilization behaviour, a neuropsychological study of 75 patients. Ann Neurol 1986; 19: 326-34.
Public survey of
resource
allocation
preferences S!R,—Malcolm Dean (Dec 14, p 1511) points out the importance of
asking the right questions in surveys of public opinion. Straightforward questions such as "do you think the money spent on X is enough?" are unlikely to lead to useful results. Everyone would like more good things and can be expected to be in favour of higher expenditure on them. Questions may provide more realistic and meaningful answers if they take into account resource constraints. The Cardiff Health Survey1,2 examined attitudes to and knowledge of a wide range of health subjects in a random sample of adults. One part of the survey looked at the way in which people would allocate resources among publicly funded services. Respondents were asked how they would allocate a fixed sum among all such services. They were given a breakdown of how each pound was spent by government and local councils in Britain. They were asked how they would reallocate that pound to these services. The table shows the breakdown of actual spending and the mean and median values for respondents. Of 722 persons who were interviewed only 4 (0-5%) did not attempt an answer. A further 17 (2%) respondents gave allocations that did not add up to 100 pence (range 89 to 116p) and these were adjusted to do so. These results ACTUAL AND SUGGESTED BREAKDOWN, IN PENCE, OF EACH POUND SPENT ON VARIOUS SERVICES (1986 FIGURES)
185
indicate the increases in expenditure on the National Health Service that the public want, and what reductions in other services would be necessary to achieve this. Increases in spending on health and social services could be achieved by reductions for defence. This type of questioning could also be used to investigate other expenditure allocation issues. Health authorities in the UK are being encouraged to seek and take into account the views of the public in their decisions about purchasing of services. Questions that merely ask people to indicate what developments in services they want, or that ask for assignment of priorities to services, will not provide answers that take into account resource constraints. The use of questions that set resource allocation difficulties should be
considered. Public Health Directorate, Bath District Health Authority, Newbridge Hill, Bath BA1 3QE, UK 1
ANDREW J. RICHARDSON MARK C. CHARNY
Charny MC, Lewis PA. Does health knowledge affect eating habits? Health Educ J 1987; 4: 172-76.
2. Charny MC, Farrow SC, Lewis PA. Who Health Trends 1987; 19: 3-5.
is
using cervical cancer screening services?
payment before intervening on their behalf. Few potential donor families are made aware of the grave consequences of their refusal to donate. People should be told in no uncertain terms that in death there can be life. At the same time, however, I do not believe that we need to confuse the value of human life by bartering death in hopes of convincing people of their moral obligation to save lives. Let us tell it like it is, before tragedy makes us reluctant to do so. Battelle-Seattle Research Center, Seattle, Washington 98105, USA
1. Evans RW.
Organ donation: facts and figures. Dial Transplant 1990, 19: 234-37, 240. RW, Manninen DL, Dong FB. The National Cooperative Transplantation study: final report. Seattle, WA: Battelle-Seattle Research Center, June, 1991. 3. Manninen DL, Evans RW. Public attitudes and behavior regarding organ donation. JAMA 1985; 253: 3111-15. 4. Evans RW, Onans CE, Ascher NL The potential supply of organ donors: an assessment of the efficiency of organ procurement efforts in the United States. JAMA (in press). 5. Evans RW. The private sector vis-a-vis the government in future funding of organ transplantation Transplant Proc 1990; 22: 975-79. 6. Dixon J, Welch HG. Priority setting lessons from Oregon. Lancet 1991; 337:891-94. 7. Dean M. Is your treatment economic, effective, efficient? Lancet 1991; 337:480-81. 2 Evans
Incentives for organ donation
Colour blindness and
SIR,-Dr Kittur and colleagues’ data (Dec 7, p 1441) provide little support for the use of financial incentives or presumed consent as methods to increase organ donation. They seem unaware of the risk-benefit ratio associated with such policies,’ and fail to consider the impact financial incentives would have on the cost of already
expensive transplant procedures. The median charges ($) for transplantations in the USA are :2 Kidney 39625
Heart 91570
Llver 145795
Heart/ lung 134881
Pancreas 66917
The ranges for each procedure are considerable, with the costs of individual heart and liver transplants exceeding$1-3 million. Donor organ acquisition charges vary greatly too: some
Organ Kidney Heart Liver
Heart/lung Pancreas
Low 682 390 4775 5149 585
Cost z Median
High
12 290 12578 16281 12028 15400
87629 60000 65652 38000 32952
What is the effect of presumed consent on donation rates? The data are rarely consistent. Previous surveys of the US public have shown little support for presumed consent.3 For example, in 1984, over 85% of Americans rejected the notion of presumed consent, and only 25% felt that brain death constituted death (another 25% were
uncertain).
We have evaluated the efficiency (the number of potential donors from whom organs are actually procured) of organ procurement efforts in the USA.4 Depending on the criteria used, the organ procurement system is between 37% and 59% efficient. Most noteworthy is the great variability throughout the country. Some states and organ procurement organisations obtain 90% of potential donors, whereas others fall below 20%. Organ procurement efforts can clearly be very efficient, without introducing the risks associated with presumed consent or financial incentives. Advocates of organ donation should recognise that transplantation is not always accorded a high priority among health-care policy makers.5,6 In a survey of public health directors in England and Wales, of twelve treatments ranked, heart transplantation was tenth and liver transplantation eleventhNot surprisingly, some public health insurers in the USA have begun to reconsider payment for some transplant procedures, even though transplants are often as cost-effective as other covered treatments. 12 Thus we should look for methods to reduce rather than increase the cost of transplantation. We should appeal to altruism in organ donation as a way for people to contribute towards saving lives cost-effectively. In the USA, since the transplant recipient often bears donor-organ acquisition costs, the use of financial incentives to encourage people to donate organs to help another human being is the functional equivalent of asking the victim of a crime for
ROGER W. EVANS
pathologists
SIR,-Certainly it must be surprising for most of your readers to learn that optimum colour vision is not important for a pathologist to make accurate histological diagnoses (Nov 23, p 1302). I remember my first teacher, a very accurate pathologist, proudly announcing that he was colour blind, which only caused him difficulties in searching for acid-fast bacilli with Ziehl-Neelsen stain. However, the last sentence in your editorial, describing the pathologist as "the person peering down a microscope at a biopsy specimen" struck me in its resemblance to the old-fashioned description of the pathologist as "the meek person in the basement". Times have changed. Maybe the coloured vision of nonpathologists on pathology should be adjusted under standardised lighting conditions? Department of Pathology, University Hospital Nijmegen, 6500 HB Nijmegen, Netherlands
M.
J. J. T. BOGMAN
Computer-based knowledge systems SIR,-Dr Wyatt in his review of computer-based knowledge systems (Dec 7, p 1431) correctly says, "Floppy disks are not the ideal vehicle for knowledge bases because they are fragile and have limited capacity". They are, however, increasingly used to serve an important current awareness function that Wyatt does not adequately discuss. This application gives them some advantage over the compact disc read-only memory (CD-ROM), which is now much used for information retrieval. Users of the CD-ROM version of the MEDLINE database, for example, will have noticed that there are often pronounced time lags between the publication of articles and their appearance in this database-commonly 3-6 months, and sometimes more. This can also affect other CD-ROM databases. Sole reliance on CD-ROM databases will result therefore in ignorance of information for substantial periods. Two factors contribute to such delays. The first, as Wyatt notes (Nov 30, p 1368), is the time consumed in the application of the indexing systems that are used to assign consistent subject headings to articles. The second is the CD-ROM medium itself which, because of the number of production processes involved, lends itself at best to monthly updating schedules. This a gap that weekly updating services on floppy disk can fill. Although floppy disks do not have the storage capacity of CD-ROM they are well suited to the frequent provision of details about new medical publications. Four medical updating services, issued at weekly intervals, have become available on floppy disk in the past 3 years (table). Each service aims to offer access to the contents of various medical journals within a short time after publication (typically 4-6 weeks and sometimes less), thereby providing more current information than do CD-ROM databases.
leaves
Psychiatric diagnoses and diseases SIR,-Professor Szasz’s article (Dec 21/28, p 1574) is stimulating. one can take issue with his view of psychiatric diagnoses. Diagnoses are labels. As labels they provide us with a common language to describe events, and they allow us to differentiate and manipulate reality. Labels are only as useful as they are true: if they do not accurately represent the underlying reality they will not be very helpful. One can make two claims with respect to diagnoses as labels in psychiatric illness-first, that such illness is not well understood, so its labels are a poor representation of reality or, second, that psychiatric illness is a myth, that it has no reality, and therefore labels are meaningless. Much of medicine deals with poorly fitting labels, and it is not unexpected that psychiatry shares this difficulty. But Szasz seems to be taking the strong position that psychiatric illness is a myth, and that psychiatric diagnoses confer an appearance of reality where none exists. Almost all illness presents with changes in behaviour. A person with pneumonia coughs, breathes rapidly, is inactive, and complains of lack of interest in life. A person with depression loses weight, cannot sleep, is inactive, and complains of lack of interest in life. Both patients are dysfunctional, but how can their illnesses be differentiated? It avails them (and us) little if we say that we cannot separate these two patients because of our lack of understanding or because of the complexity of their diseases. Just because an illness is not well understood, or because it is very complex, does not negate its reality. Thus, we may need a higher level of analysis than brain synapses to understand depression, just as we need a higher level of analysis than atomic particles to understand cells. But our inability to explain cells by the activity of individual atoms does not mean that cells do not have a physical basis; it merely means that the physical basis of cells is very complex, and that certain simplifying assumptions can be made that allow us to reduce this complexity to a manageable level. Just because we cannot explain schizophrenia by neuronal processes does not mean that it is not a physical illness. To assert that there is a mental realm that is independent of the physical realm at work in psychiatric illness, and that this mental level is not amenable to psychiatric diagnosis, is to fall into the mind/body dualism trap-a trap from which no one has yet escaped. But
Department of Medicine, Medical College of Wisconsin, Milwaukee County Medical Complex, Milwaukee, Wisconsin 53226, USA
HARRY B. BURKE
SIR,-I enjoyed reading Professor Szasz’ article for its elegant style and stimulating arguments; unfortunately, his basic thesis is just as absurd now as it was twenty years ago when I read it as a medical student. Szasz seems to be being deliberately obtuse about what is meant by the term disease and is also remarkably coy about what he means by the notions of mind and free will. This would not matter too much if the debate were only among professionals: the real harm done by Szasz and his sympathisers is that they influence public policy when their views are picked up by the lay press, politicians, and others, and are used to justify grotesque notions such as that no one should remain in a long-stay psychiatric institution since the inmates of such establishments are not ill. Throughout history (and in all cultures) certain individuals have been recognised whose behaviour is so bizarre, so antisocial, so self-destructive (or a combination of all three) that it falls outside any sensible definition of normal. To anyone who has observed psychotic bahaviour at first hand it is inconceivable that such behaviour could arise from the exercise of free will; once demonic possession had been discarded as a likely cause the most attractive model became that of physical disease, especially when it became clear that certain forms of abnormal behaviour were indeed caused by organic diseases (thyrotoxicosis, epilepsy, tertiary syphilis). It is nonsense to argue that because mental illness is hard to define and to classify it does not exist--one could say exactly the same about love, jealousy, hatred, compassion, or a whole host of other emotional and mental states. Friarage Hospital, Northallerton, North Yorkshire DL6 1JG, UK
ROGER A. FISKEN
SIR,-Professor Szasz claims that "psychiatric diagnoses do not point to anatomical or physiological lesions and do not suggest causal agents, but allude only to human behaviours". In other words, human behaviours, when categorised by psychiatrists in diagnoses, cannot be the result of abnormal brain structure or function. Such a claim contradicts such a large number of studies that it was perhaps difficult for Szasz to choose even a representative sample to debunk, but I do not feel that this justifies omitting all reference to these studies. Every week The Lancet sensibly advises authors to assume that readers start from near-ignorance. Surely then authors, and editors, should ensure that ignorance is not exploited to lead readers into a partial viewpoint? Readers of Szasz’ article might not know of relevant reports or of claims that in some circumstances schizophrenia, a psychiatric diagnosis, points to structural abnormalities in the brain that can be seen on radiographs.’ However, perhaps Szasz’ argument is with diagnoses made by psychiatrists, in which case surely he should say whether neurological diagnoses are similarly misguided. What for instance does he think of the work of Professor Lhermitte, who finds that patients with inferior prefrontal lesions are at the mercy of environmental cues (eg, the sight of a tongue depressor led one woman to begin examining the professor’s throat)? Does Szasz think that this unusual human behaviour is unrelated to those brain lesions? Maudsley Hospital,
JONATHAN FLINT
London SE5 8AZ, UK
1. Suddath RL, Christison GW, Torrey EF, Casanova MF, Weinberger DR Anatomical abnormalities in the brains of monozygotic twins discordant for schizophrenia. N Engl J Med 1990; 322: 789-94. 2. Lhermitte F, Pillon B, Serdaru M. Human autonomy and the front lobes, I. Imitation and utilization behaviour, a neuropsychological study of 75 patients. Ann Neurol 1986; 19: 326-34.
Public survey of
resource
allocation
preferences S!R,—Malcolm Dean (Dec 14, p 1511) points out the importance of
asking the right questions in surveys of public opinion. Straightforward questions such as "do you think the money spent on X is enough?" are unlikely to lead to useful results. Everyone would like more good things and can be expected to be in favour of higher expenditure on them. Questions may provide more realistic and meaningful answers if they take into account resource constraints. The Cardiff Health Survey1,2 examined attitudes to and knowledge of a wide range of health subjects in a random sample of adults. One part of the survey looked at the way in which people would allocate resources among publicly funded services. Respondents were asked how they would allocate a fixed sum among all such services. They were given a breakdown of how each pound was spent by government and local councils in Britain. They were asked how they would reallocate that pound to these services. The table shows the breakdown of actual spending and the mean and median values for respondents. Of 722 persons who were interviewed only 4 (0-5%) did not attempt an answer. A further 17 (2%) respondents gave allocations that did not add up to 100 pence (range 89 to 116p) and these were adjusted to do so. These results ACTUAL AND SUGGESTED BREAKDOWN, IN PENCE, OF EACH POUND SPENT ON VARIOUS SERVICES (1986 FIGURES)
185
indicate the increases in expenditure on the National Health Service that the public want, and what reductions in other services would be necessary to achieve this. Increases in spending on health and social services could be achieved by reductions for defence. This type of questioning could also be used to investigate other expenditure allocation issues. Health authorities in the UK are being encouraged to seek and take into account the views of the public in their decisions about purchasing of services. Questions that merely ask people to indicate what developments in services they want, or that ask for assignment of priorities to services, will not provide answers that take into account resource constraints. The use of questions that set resource allocation difficulties should be
considered. Public Health Directorate, Bath District Health Authority, Newbridge Hill, Bath BA1 3QE, UK 1
ANDREW J. RICHARDSON MARK C. CHARNY
Charny MC, Lewis PA. Does health knowledge affect eating habits? Health Educ J 1987; 4: 172-76.
2. Charny MC, Farrow SC, Lewis PA. Who Health Trends 1987; 19: 3-5.
is
using cervical cancer screening services?
payment before intervening on their behalf. Few potential donor families are made aware of the grave consequences of their refusal to donate. People should be told in no uncertain terms that in death there can be life. At the same time, however, I do not believe that we need to confuse the value of human life by bartering death in hopes of convincing people of their moral obligation to save lives. Let us tell it like it is, before tragedy makes us reluctant to do so. Battelle-Seattle Research Center, Seattle, Washington 98105, USA
1. Evans RW.
Organ donation: facts and figures. Dial Transplant 1990, 19: 234-37, 240. RW, Manninen DL, Dong FB. The National Cooperative Transplantation study: final report. Seattle, WA: Battelle-Seattle Research Center, June, 1991. 3. Manninen DL, Evans RW. Public attitudes and behavior regarding organ donation. JAMA 1985; 253: 3111-15. 4. Evans RW, Onans CE, Ascher NL The potential supply of organ donors: an assessment of the efficiency of organ procurement efforts in the United States. JAMA (in press). 5. Evans RW. The private sector vis-a-vis the government in future funding of organ transplantation Transplant Proc 1990; 22: 975-79. 6. Dixon J, Welch HG. Priority setting lessons from Oregon. Lancet 1991; 337:891-94. 7. Dean M. Is your treatment economic, effective, efficient? Lancet 1991; 337:480-81. 2 Evans
Incentives for organ donation
Colour blindness and
SIR,-Dr Kittur and colleagues’ data (Dec 7, p 1441) provide little support for the use of financial incentives or presumed consent as methods to increase organ donation. They seem unaware of the risk-benefit ratio associated with such policies,’ and fail to consider the impact financial incentives would have on the cost of already
expensive transplant procedures. The median charges ($) for transplantations in the USA are :2 Kidney 39625
Heart 91570
Llver 145795
Heart/ lung 134881
Pancreas 66917
The ranges for each procedure are considerable, with the costs of individual heart and liver transplants exceeding$1-3 million. Donor organ acquisition charges vary greatly too: some
Organ Kidney Heart Liver
Heart/lung Pancreas
Low 682 390 4775 5149 585
Cost z Median
High
12 290 12578 16281 12028 15400
87629 60000 65652 38000 32952
What is the effect of presumed consent on donation rates? The data are rarely consistent. Previous surveys of the US public have shown little support for presumed consent.3 For example, in 1984, over 85% of Americans rejected the notion of presumed consent, and only 25% felt that brain death constituted death (another 25% were
uncertain).
We have evaluated the efficiency (the number of potential donors from whom organs are actually procured) of organ procurement efforts in the USA.4 Depending on the criteria used, the organ procurement system is between 37% and 59% efficient. Most noteworthy is the great variability throughout the country. Some states and organ procurement organisations obtain 90% of potential donors, whereas others fall below 20%. Organ procurement efforts can clearly be very efficient, without introducing the risks associated with presumed consent or financial incentives. Advocates of organ donation should recognise that transplantation is not always accorded a high priority among health-care policy makers.5,6 In a survey of public health directors in England and Wales, of twelve treatments ranked, heart transplantation was tenth and liver transplantation eleventhNot surprisingly, some public health insurers in the USA have begun to reconsider payment for some transplant procedures, even though transplants are often as cost-effective as other covered treatments. 12 Thus we should look for methods to reduce rather than increase the cost of transplantation. We should appeal to altruism in organ donation as a way for people to contribute towards saving lives cost-effectively. In the USA, since the transplant recipient often bears donor-organ acquisition costs, the use of financial incentives to encourage people to donate organs to help another human being is the functional equivalent of asking the victim of a crime for
ROGER W. EVANS
pathologists
SIR,-Certainly it must be surprising for most of your readers to learn that optimum colour vision is not important for a pathologist to make accurate histological diagnoses (Nov 23, p 1302). I remember my first teacher, a very accurate pathologist, proudly announcing that he was colour blind, which only caused him difficulties in searching for acid-fast bacilli with Ziehl-Neelsen stain. However, the last sentence in your editorial, describing the pathologist as "the person peering down a microscope at a biopsy specimen" struck me in its resemblance to the old-fashioned description of the pathologist as "the meek person in the basement". Times have changed. Maybe the coloured vision of nonpathologists on pathology should be adjusted under standardised lighting conditions? Department of Pathology, University Hospital Nijmegen, 6500 HB Nijmegen, Netherlands
M.
J. J. T. BOGMAN
Computer-based knowledge systems SIR,-Dr Wyatt in his review of computer-based knowledge systems (Dec 7, p 1431) correctly says, "Floppy disks are not the ideal vehicle for knowledge bases because they are fragile and have limited capacity". They are, however, increasingly used to serve an important current awareness function that Wyatt does not adequately discuss. This application gives them some advantage over the compact disc read-only memory (CD-ROM), which is now much used for information retrieval. Users of the CD-ROM version of the MEDLINE database, for example, will have noticed that there are often pronounced time lags between the publication of articles and their appearance in this database-commonly 3-6 months, and sometimes more. This can also affect other CD-ROM databases. Sole reliance on CD-ROM databases will result therefore in ignorance of information for substantial periods. Two factors contribute to such delays. The first, as Wyatt notes (Nov 30, p 1368), is the time consumed in the application of the indexing systems that are used to assign consistent subject headings to articles. The second is the CD-ROM medium itself which, because of the number of production processes involved, lends itself at best to monthly updating schedules. This a gap that weekly updating services on floppy disk can fill. Although floppy disks do not have the storage capacity of CD-ROM they are well suited to the frequent provision of details about new medical publications. Four medical updating services, issued at weekly intervals, have become available on floppy disk in the past 3 years (table). Each service aims to offer access to the contents of various medical journals within a short time after publication (typically 4-6 weeks and sometimes less), thereby providing more current information than do CD-ROM databases.
leaves