ment that is read and signed by each donor before donation. This we did. We cannot speak for every blood transfusion centre, but as far as our own centre is concerned we responded immediately to the initial request in early 1986 and to the further request in 1989. MARCELA CONTRERAS JOHN BARBARA PATRICIA HEWITT North London Blood Transfusion Centre, London NW9 5BG
1 Watkins AM. Creutzfeldt-Jakob disease and blood transfusion. BMJ 1991;302:1537. (22 June.)
Prenatal screening for Down's syndrome SIR,-In the light of recent evidence that the "triple" test is a good predictor ofDown's syndrome we write to express our concern that this investigation is not generally available on the NHS. ' All women in Stockport are offered an estimation of a fetoprotein concentration and an ultrasound scan at 16 weeks of pregnancy. On the advice of one of the local consultant obstetricians a patient of ours with a low a fetoprotein concentration (17 [tg/l) was offered a triple test at the cost of £50. We consider that if this investigation is recommended for the detection of Down's syndrome and has become a part of accepted medical practice it is indefensible not to offer it to an at risk woman and it is wrong that, depending on the area of the country in which the woman lives, the investigation is either free or not. Is this further evidence of inequality of health care or just the result of market forces? M J STONE W TAIT
S F LEVY P J ALLAN P J RILEY
Hazel Grove, Stockport SK7 4QR I Sheldon TA, Simpson J. Appraisal of a new scheme for prenatal
screening for Down's syndrome. BMJ 1991;302:1133-6. (1 1 May.)
Non-operative management of blunt splenic injury SIR,-The editorial on non-operative management of blunt splenic injury rightly emphasises the role of computed tomography (CT) in diagnosing and determining the severity of splenic injury.' Thomas and Dubbins recently noted the "universal agreement that CT is the best overall'imaging method" in splenic trauma.2 They went on, however, to review the conflicting results that different groups have had in correlating the degree of splenic trauma as shown by computed tomography with outcome, apart altogether from problems due to artefacts and false negative and false positive reports of findings on computed tomography. The fact that "CT certainly seems to be the best overall tool"2 has encouraged others to develop scoring systems to predict clinical outcome in haemodynamically stable patients on the basis of appearances on computed tomography.I4 More recently, Umlas and Cronan applied these scoring systems to 56 patients and showed conclusively that they do not predict the outcome of the injured spleen with certainty.' The serial computed tomograms that Umlas and Cronan included in their paper are a graphic testimony to the sometimes surprising natural course of splenic injury. The authors concluded that though computed tomography is an excellent aid in assessing patients with splenic injury, a small but important
188
number of patients with low scores or even normal computed tomograms experience delayed rupture of the spleen. The limitations as well as the advantages of computed tomography need to be emphasised. The decision to operate or not should be based on the overall clinical position. RICHARD FITZGERALD New Cross Hospital,
Wolverhampton WVIO OQP 1 Gibney EJ. Non-operative management of blunt splenic injury. BMJ 1991;302:1553-4. (29 June.) 2 Thomas EA, Dubbins PA. Diagnosing splenic trauma. Clin Radiol 1991;43:297-300. 3 Buntain WL, Gould HR, Mar11 KI. Predictability of splenic salvage by computed tomography.J Trauma 1988;28:24-31. 4 Resciniti A, Fink MP, Raptopoulos V, Davidoff A, Silva WE. Non operative treatment of adult splenic trauma; development of a computed tomographic scoring system that detects appropriate candidates for expectant management. J Trauma 1988;128:828-3 1. 5 Umlas SL, Cronan JJ. Splenic trauma: can CT grading systems enable prediction of successful non surgical treatment? Radiology 1991;178:481-7.
might have more weight, such as maternal influenza,' should be tested individually-that is, would it be more appropriate to use hypothesis testing with simple statistics rather than exploratory interactive statistics for such a small final group of index cases? Interestingly, the authors do find a significant association for some variables for affective psychosis. Elsewhere this group has claimed that there is no distinction between schizophrenia and affective psychosis.6 Does this association hold if all psychotic patients are analysed together, and if so shouldn't this be taken as evidence for a role for obstetric complications in the "recurrent psychoses"? The authors conclude that the data "offer little support for the suggestion that some schizophrenic illnesses are a result of birth trauma or a high risk pregnancy." This study convincingly rules out the first in this sample, but the second remains to be established, and studies specifically showing this association remain in the majority. ROBERT KERWIN WENDY WOODHOUSE
Complications of pregnancy and delivery and psychosis in adult life SIR,-We congratulate Dr D John Done and colleagues on their cohort study of birth trauma and its relation to schizophrenia. ' We are sure that methodologically their paper sets an important benchmark for further study. We think it important, however, to clarify certain points before their conclusions (which contradict those of most studies) can be accepted. The authors assume that "the nature of prenatal and perinatal events relevant to the later development of schizophrenia was the same as those responsible for stillbirth and neonatal death." The validity of this assumption is crucial to the overall conclusion. Most studies (listed in table I of their paper) have studied obstetric complications as a whole. This point is central to the hypothesis that schizophrenia (in some cases at least) is a developmental disorder arising as a result of a complication of pregnancy.2 Most of the variables included in Dr Done and colleagues' model, however, are related to birth trauma and difficult labour rather than obstetric complications. Those variables left out may be more relevant to obstetric complications in the general sense (for example, haemoglobin concentrations, previous premature birth, fetal distress). Those studies reporting positive results have indeed specifically considered more general obstetric complications,'4 therefore questioning the validity of this primary assumption. It is also relevant to this distinction between birth trauma and obstetric complications to consider the changing definitions and meanings of stillbirth and perinatal and neonatal death. For instance, compare 1958 with today: a stillbirth in 1958 is quite likely to be a neonatal death now and an abortion then may be a stillbirth now; a neonatal death then may be a healthy baby now. The reverse will be the case in studies that have looked at older cohorts. The point is that in one era of obstetric care deaths may arise from complications of pregnancy whereas in another era deaths may be related more to standards of intensive neonatology. In the changing context of obstetric care it needs to be determined to what degree obstetric variables in general as opposed to birth trauma in particular have influenced the varying studies performed in differing eras of obstetric care. The statistical tests seem sophisticated, and the model seems to entail applying 33 independent variables indiscriminately as a group to a set of data that have resulted in a small number of cases (49). One wonders whether factors that intuitively
Department of Neuroscience and Psychiatry, Institute of Psychiatry, London SE5 8AF I Done DJ, Johnstone EC, Frith CD, Golding J, Shepherd PM, Crow TJ. Complications of pregnancy and delivery in relation to psychosis in adult life: data from the British perinatal mortality survey sample. BMJ 1991;302:1576-80. (29 June.) 2 Pilowsky L, Kerwin R, Murray RM. Neurodevelopment and schizophrenia in etiology of mental disorder. In: Kringlen E, Lavik NJ, Torgenson S, eds. Oslo: Oslo University Press, 1991:169-82. 3 Lewis SW, Murray RM. Obstetric complications, neurodevelopment deviance and risk of schizophrenia. J Psychiatr Res 1987;21:413-22. 4 Parnas J, Schulsinger F, Teasdale TW, Schulsinger H, Feldman PM, Mednick SA. Perinatal complications and clinical outcome within the schizophrenia spectrum. Br J Psychiatry
1982;140:416-20. 5 O'Callaghan E, Sham P, Takei N, Glover G, Murray RM. Schizophrenia after prenatal exposure to 1957 A2 influenza epidemic. Lancet 1991;337:1248-50. 6 Crow TJ. The continuum of psychosis and its implications for the structure of the gene. Brj Psychiatry 1986;149:419-29.
An archaic training system SIR,-Dr M J Evans describes how a "star" doctor was impelled to change career after repeatedly failing postgraduate examinations.' This kind of thing is a familiar story. We have all known brilliant young doctors who failed either the MRCP or FRCS examination (especially the primary parts) despite having glittering records of achievement (such as winning undergraduate prizes or honours and gaining intercalated science degrees or PhDs) and being universally respected for their clinical knowledge and judgment. Typically, each failure is thought of as an unfortunate exception: there was no reason for the person to fail and yet he or she did. There may be two causes. Either the examinations for the MRCP and FRCS are uniquely able to reveal what no other test or competent authority can-namely, that the candidates are truly inadequate-or the examinations themselves are at fault. I think that the second possibility deserves serious consideration. Historically, the ancient medical corporations have resisted internal reform and have often resolutely opposed improvements in education except when these coincided with financial interest. We have been brought up to accept with equanimity superb candidates being thrown on the mercy of an assessment system that has, on the face of it, all the validity of a lottery. If the colleges will not reform this blatant injustice perhaps change should be initiated by external pressure from the profession as a whole. It cannot be good for medicine, or patients, to have physicians and surgeons selected by a roulette
BMJ VOLUME 303
20 JULY 1991
1 Watkins AM. Creutzfeldt-Jakob disease and blood transfusion. BMJ 1991;302:1537. (22 June.)
Prenatal screening for Down's syndrome SIR,-In the light of recent evidence that the "triple" test is a good predictor ofDown's syndrome we write to express our concern that this investigation is not generally available on the NHS. ' All women in Stockport are offered an estimation of a fetoprotein concentration and an ultrasound scan at 16 weeks of pregnancy. On the advice of one of the local consultant obstetricians a patient of ours with a low a fetoprotein concentration (17 [tg/l) was offered a triple test at the cost of £50. We consider that if this investigation is recommended for the detection of Down's syndrome and has become a part of accepted medical practice it is indefensible not to offer it to an at risk woman and it is wrong that, depending on the area of the country in which the woman lives, the investigation is either free or not. Is this further evidence of inequality of health care or just the result of market forces? M J STONE W TAIT
S F LEVY P J ALLAN P J RILEY
Hazel Grove, Stockport SK7 4QR I Sheldon TA, Simpson J. Appraisal of a new scheme for prenatal
screening for Down's syndrome. BMJ 1991;302:1133-6. (1 1 May.)
Non-operative management of blunt splenic injury SIR,-The editorial on non-operative management of blunt splenic injury rightly emphasises the role of computed tomography (CT) in diagnosing and determining the severity of splenic injury.' Thomas and Dubbins recently noted the "universal agreement that CT is the best overall'imaging method" in splenic trauma.2 They went on, however, to review the conflicting results that different groups have had in correlating the degree of splenic trauma as shown by computed tomography with outcome, apart altogether from problems due to artefacts and false negative and false positive reports of findings on computed tomography. The fact that "CT certainly seems to be the best overall tool"2 has encouraged others to develop scoring systems to predict clinical outcome in haemodynamically stable patients on the basis of appearances on computed tomography.I4 More recently, Umlas and Cronan applied these scoring systems to 56 patients and showed conclusively that they do not predict the outcome of the injured spleen with certainty.' The serial computed tomograms that Umlas and Cronan included in their paper are a graphic testimony to the sometimes surprising natural course of splenic injury. The authors concluded that though computed tomography is an excellent aid in assessing patients with splenic injury, a small but important
188
number of patients with low scores or even normal computed tomograms experience delayed rupture of the spleen. The limitations as well as the advantages of computed tomography need to be emphasised. The decision to operate or not should be based on the overall clinical position. RICHARD FITZGERALD New Cross Hospital,
Wolverhampton WVIO OQP 1 Gibney EJ. Non-operative management of blunt splenic injury. BMJ 1991;302:1553-4. (29 June.) 2 Thomas EA, Dubbins PA. Diagnosing splenic trauma. Clin Radiol 1991;43:297-300. 3 Buntain WL, Gould HR, Mar11 KI. Predictability of splenic salvage by computed tomography.J Trauma 1988;28:24-31. 4 Resciniti A, Fink MP, Raptopoulos V, Davidoff A, Silva WE. Non operative treatment of adult splenic trauma; development of a computed tomographic scoring system that detects appropriate candidates for expectant management. J Trauma 1988;128:828-3 1. 5 Umlas SL, Cronan JJ. Splenic trauma: can CT grading systems enable prediction of successful non surgical treatment? Radiology 1991;178:481-7.
might have more weight, such as maternal influenza,' should be tested individually-that is, would it be more appropriate to use hypothesis testing with simple statistics rather than exploratory interactive statistics for such a small final group of index cases? Interestingly, the authors do find a significant association for some variables for affective psychosis. Elsewhere this group has claimed that there is no distinction between schizophrenia and affective psychosis.6 Does this association hold if all psychotic patients are analysed together, and if so shouldn't this be taken as evidence for a role for obstetric complications in the "recurrent psychoses"? The authors conclude that the data "offer little support for the suggestion that some schizophrenic illnesses are a result of birth trauma or a high risk pregnancy." This study convincingly rules out the first in this sample, but the second remains to be established, and studies specifically showing this association remain in the majority. ROBERT KERWIN WENDY WOODHOUSE
Complications of pregnancy and delivery and psychosis in adult life SIR,-We congratulate Dr D John Done and colleagues on their cohort study of birth trauma and its relation to schizophrenia. ' We are sure that methodologically their paper sets an important benchmark for further study. We think it important, however, to clarify certain points before their conclusions (which contradict those of most studies) can be accepted. The authors assume that "the nature of prenatal and perinatal events relevant to the later development of schizophrenia was the same as those responsible for stillbirth and neonatal death." The validity of this assumption is crucial to the overall conclusion. Most studies (listed in table I of their paper) have studied obstetric complications as a whole. This point is central to the hypothesis that schizophrenia (in some cases at least) is a developmental disorder arising as a result of a complication of pregnancy.2 Most of the variables included in Dr Done and colleagues' model, however, are related to birth trauma and difficult labour rather than obstetric complications. Those variables left out may be more relevant to obstetric complications in the general sense (for example, haemoglobin concentrations, previous premature birth, fetal distress). Those studies reporting positive results have indeed specifically considered more general obstetric complications,'4 therefore questioning the validity of this primary assumption. It is also relevant to this distinction between birth trauma and obstetric complications to consider the changing definitions and meanings of stillbirth and perinatal and neonatal death. For instance, compare 1958 with today: a stillbirth in 1958 is quite likely to be a neonatal death now and an abortion then may be a stillbirth now; a neonatal death then may be a healthy baby now. The reverse will be the case in studies that have looked at older cohorts. The point is that in one era of obstetric care deaths may arise from complications of pregnancy whereas in another era deaths may be related more to standards of intensive neonatology. In the changing context of obstetric care it needs to be determined to what degree obstetric variables in general as opposed to birth trauma in particular have influenced the varying studies performed in differing eras of obstetric care. The statistical tests seem sophisticated, and the model seems to entail applying 33 independent variables indiscriminately as a group to a set of data that have resulted in a small number of cases (49). One wonders whether factors that intuitively
Department of Neuroscience and Psychiatry, Institute of Psychiatry, London SE5 8AF I Done DJ, Johnstone EC, Frith CD, Golding J, Shepherd PM, Crow TJ. Complications of pregnancy and delivery in relation to psychosis in adult life: data from the British perinatal mortality survey sample. BMJ 1991;302:1576-80. (29 June.) 2 Pilowsky L, Kerwin R, Murray RM. Neurodevelopment and schizophrenia in etiology of mental disorder. In: Kringlen E, Lavik NJ, Torgenson S, eds. Oslo: Oslo University Press, 1991:169-82. 3 Lewis SW, Murray RM. Obstetric complications, neurodevelopment deviance and risk of schizophrenia. J Psychiatr Res 1987;21:413-22. 4 Parnas J, Schulsinger F, Teasdale TW, Schulsinger H, Feldman PM, Mednick SA. Perinatal complications and clinical outcome within the schizophrenia spectrum. Br J Psychiatry
1982;140:416-20. 5 O'Callaghan E, Sham P, Takei N, Glover G, Murray RM. Schizophrenia after prenatal exposure to 1957 A2 influenza epidemic. Lancet 1991;337:1248-50. 6 Crow TJ. The continuum of psychosis and its implications for the structure of the gene. Brj Psychiatry 1986;149:419-29.
An archaic training system SIR,-Dr M J Evans describes how a "star" doctor was impelled to change career after repeatedly failing postgraduate examinations.' This kind of thing is a familiar story. We have all known brilliant young doctors who failed either the MRCP or FRCS examination (especially the primary parts) despite having glittering records of achievement (such as winning undergraduate prizes or honours and gaining intercalated science degrees or PhDs) and being universally respected for their clinical knowledge and judgment. Typically, each failure is thought of as an unfortunate exception: there was no reason for the person to fail and yet he or she did. There may be two causes. Either the examinations for the MRCP and FRCS are uniquely able to reveal what no other test or competent authority can-namely, that the candidates are truly inadequate-or the examinations themselves are at fault. I think that the second possibility deserves serious consideration. Historically, the ancient medical corporations have resisted internal reform and have often resolutely opposed improvements in education except when these coincided with financial interest. We have been brought up to accept with equanimity superb candidates being thrown on the mercy of an assessment system that has, on the face of it, all the validity of a lottery. If the colleges will not reform this blatant injustice perhaps change should be initiated by external pressure from the profession as a whole. It cannot be good for medicine, or patients, to have physicians and surgeons selected by a roulette
BMJ VOLUME 303
20 JULY 1991
