- Email: [email protected]
PATHOLOGY TESTS
406
uptake of the vaccine increased only after the 75%. Should market forces be allowed to play’such a large part in deciding whether a vaccine that reduces morbidity, mortality, and the development of hepatocellular cancer is used? It seems shortsighted that countries, whether they have a health service or not, cannot see the economic sense of vaccinating homosexuals against hepatitis B. I realise that resources are limited and that "new" programmes and initiatives have to pay for themselves. We have shown that this does happen in relation to vaccinating homosexuals in the UK.’ We analysed the financial cost and on
the fact that the
price had fallen by
benefits of a vaccination programme designed to prevent acute hepatitis B in homosexual men. Under various assumptions the total costs of screening and vaccination ranged from 2.2 to 4.8 million and the benefits or savings ranged from 3.9 to 24.4 million. The benefits that we costed were the savings from less primary and hospital care, sickness absence, and premature mortality. We concluded that considerable savings.could be made to the national economy by offering vaccination to homosexuals. Our calculations took into account only the acute aspects of hepatitis B, and had we been able to calculate the costs of the chronic sequelae of this disease (chronic persistent and active hepatitis, cirrhosis, and carcinoma), the savings, compared with the costs, would have been greatly increased. Academic Department of Genito-urinary Middlesex Hospital Medical School, London W 1N 8AA 1 Adler
Medicine,
M. W. ADLER
MW, Belsey EM, McCutchann JA, MIndel A. Should homosexuals be hepatitis B virus? Cost and benefit assessment. Br Med J 1983;
vaccinated against 286: 1621-24
PATHOLOGY TESTS
SIR,— Your editorial (June 9, p 1278) on the rising demands made on laboratory services mentioned a London hospital where the outof-hours pathology requests of house-officers were reviewed by their own registrars; this resulted in a "halving of the number of tests and a very considerable saving in fees paid to technicians for after-hours work". The microbiology service for the central Bristol hospitals has assessed a different system of screening of on-call requests and achieved different results. During one week in each of five months all out-of hours requests were referred to a member of the microbiology department medical staff (registrar, senior registrar, or consultant/professor) who completed a questionnaire and assessed the usefulness of the investigation on a four-point scale, from "useless" to "essential". If the microbiologist approved the test he or she passed it on to the medical laboratory scientific officer (MLSO) on call. There were few disputes requiring consultant referral. 189 requests were assessed during this period, 44% from the paediatric services (partly reflecting intensive activity in specialist neonatal and haematology/oncology units). 40% of requests were judged essential, 37% clearly useful, and only 9% useless. Only 29 requests (15%) were rejected. We did not find that requests from junior clinical staff were more likely to be rejected than requests from their seniors. The calls undertaken by the MLSO staff during these five weeks of vetting were compared with those of the normal service during the same period (excluding exceptional weeks with public holidays), 19 weeks in all. Although some of the rejections saved the cost of a call, the saving was small. The mean numbers of calls during the period of normal service and the period of approval by a microbiologist were 2 -56 and 2 - 12, respectively, on weekday nights and 6 -00 and 5 - 40 on Saturdays and Sundays. Within the variation among individual days and weeks in the normal service these differences are not significant (p>0.05, by Student’s t test and, for weekends, White’s test of rank sums). Our aim was to institute a discriminating but flexible system of approval of these requests. A more severe attitude by any staff with authority could reduce further the number processed. After reviewing our experience in this exercise, we believe that, in our district and in microbiology, emergency requests should not be singled out for criticism and for cuts. We agree with you that the attitude of the clinical consultant is crucial in setting the climate in
which laboratory tests are generated. While there is room for education in the discriminating use of some emergency investigations, our on-call requests reflect the climate of clinical endeavour prevailing at all times in the service; when this is curtailed it will be reasonable to expect on-call requests to decline also. We thank the medical and scientific staff and MLSOs who cooperated in this
experiment. Microbiology Department, Bristol Royal Infirmary, Bristol BS2 8HW
G. A. J. HARRISON D. C. E. SPELLER
AN END TO ANTENATAL OESTROGEN MONITORING?
SIR,—The effect of abolishing antenatal oestrogen testing for one (May 26, p 1171) was an apparently unaltered perinatal mortality rate at St George’s Hospital, London. Professor Chard (June 2, p 1236) argues that this outcome might have been fortuitous, that most people gave up urine testing long before 1983, year
and that "the final selection of [antenatal] tests must be based on proper scientific study". It is certainly difficult to refute the chance outcome view. Three years ago I reviewed the urine vs blood oestriol controversy at a meeting of the Association of Clinical Biochemists, concluding that plasma unconjugated oestriol was the better indicator of fetal function and a more up-to-date reflection of fetal oestriol production. So it cannot be successfully argued that stopping antenatal "at risk" testing for plasma oestriol (rather than urine oestrogens) will necessarily result in no harm. On the other hand, experience in East Berkshire’ does prompt me to support the withdrawal of this biochemical service. Since 1979 only two of the four consultant obstetricians in this health district have asked for plasma oestriols and to date there is no evidence that their perinatal mortality rates are better than those of their colleagues who do not request plasma oestriols. As Chard knows, blood human placental lactogen (hPL) is not a true alternative since it reflects placental, not fetoplacental, function. He chose to refer to a controlled trial championing it, rather than to an equally good trial2 revealing that antenatal hPL screening did not improve perinatal outcome. Chard’s point about selecting special biochemical tests scientifically has been authoritatively reasoned and advocated by Holland and Whitehead;3it applies to choice among pathological tests. However, where in-vivo electronic-engineering monitoring devices are proposed as alternatives to in-vitro biochemical testing, it may be impossible and/or unethical to procure statistical proof of superiority. I predicted in May, 1981, in the DHSS Advisory Committee on the Assessment of Laboratory Standards, that advanced ultrasonography and cardiotocography would overtake and supplant plasma oestriol estimations within five years-a development never dreamed of when, eighteen years ago, I had pressed urine oestrogen testing on to my Canadian obstetric colleagues. It looks as though I am not going to be far out. Clinical Biochemistry Department, Wexham Park Hospital.
D. WATSON
Slough, Berkshire 5L2 4HL
1. Simmons SC Feto-placental function tests Lancet 1978; ii: 1096 2 Zlatnik FJ, Varner MW, Hawser KS Human placental lactogen: A 3
predictor of perinatal outcome? Obstet Gynecol 1979, 54: 205-10 Holland WW, Whitehead TP. Value of new laboratory tests in diagnosis and treatment Lancet 1974; ii. 391-94.
MICROWAVE CATARACT IN RADIOLINEMEN AND CONTROLS
SIR,—Microwave irradiation is cataractogenic in laboratory animals. Some studies have shown no excess of cataract in people with possible occupational exposure to microwave irradiation2,3 while others 4,5 have revealed an apparent increase in lens opacities (including posterior subcapsular opacities, PSC) in persons with6 possible occupational microwave exposure. According to Zaret microwave cataract occurs, early in its course, as a PSC. Radio and television broadcasting and repeater towers emit microwaves. Radiolinemen who erect and maintain such for microwave cataract.
towers
could be at risk
uptake of the vaccine increased only after the 75%. Should market forces be allowed to play’such a large part in deciding whether a vaccine that reduces morbidity, mortality, and the development of hepatocellular cancer is used? It seems shortsighted that countries, whether they have a health service or not, cannot see the economic sense of vaccinating homosexuals against hepatitis B. I realise that resources are limited and that "new" programmes and initiatives have to pay for themselves. We have shown that this does happen in relation to vaccinating homosexuals in the UK.’ We analysed the financial cost and on
the fact that the
price had fallen by
benefits of a vaccination programme designed to prevent acute hepatitis B in homosexual men. Under various assumptions the total costs of screening and vaccination ranged from 2.2 to 4.8 million and the benefits or savings ranged from 3.9 to 24.4 million. The benefits that we costed were the savings from less primary and hospital care, sickness absence, and premature mortality. We concluded that considerable savings.could be made to the national economy by offering vaccination to homosexuals. Our calculations took into account only the acute aspects of hepatitis B, and had we been able to calculate the costs of the chronic sequelae of this disease (chronic persistent and active hepatitis, cirrhosis, and carcinoma), the savings, compared with the costs, would have been greatly increased. Academic Department of Genito-urinary Middlesex Hospital Medical School, London W 1N 8AA 1 Adler
Medicine,
M. W. ADLER
MW, Belsey EM, McCutchann JA, MIndel A. Should homosexuals be hepatitis B virus? Cost and benefit assessment. Br Med J 1983;
vaccinated against 286: 1621-24
PATHOLOGY TESTS
SIR,— Your editorial (June 9, p 1278) on the rising demands made on laboratory services mentioned a London hospital where the outof-hours pathology requests of house-officers were reviewed by their own registrars; this resulted in a "halving of the number of tests and a very considerable saving in fees paid to technicians for after-hours work". The microbiology service for the central Bristol hospitals has assessed a different system of screening of on-call requests and achieved different results. During one week in each of five months all out-of hours requests were referred to a member of the microbiology department medical staff (registrar, senior registrar, or consultant/professor) who completed a questionnaire and assessed the usefulness of the investigation on a four-point scale, from "useless" to "essential". If the microbiologist approved the test he or she passed it on to the medical laboratory scientific officer (MLSO) on call. There were few disputes requiring consultant referral. 189 requests were assessed during this period, 44% from the paediatric services (partly reflecting intensive activity in specialist neonatal and haematology/oncology units). 40% of requests were judged essential, 37% clearly useful, and only 9% useless. Only 29 requests (15%) were rejected. We did not find that requests from junior clinical staff were more likely to be rejected than requests from their seniors. The calls undertaken by the MLSO staff during these five weeks of vetting were compared with those of the normal service during the same period (excluding exceptional weeks with public holidays), 19 weeks in all. Although some of the rejections saved the cost of a call, the saving was small. The mean numbers of calls during the period of normal service and the period of approval by a microbiologist were 2 -56 and 2 - 12, respectively, on weekday nights and 6 -00 and 5 - 40 on Saturdays and Sundays. Within the variation among individual days and weeks in the normal service these differences are not significant (p>0.05, by Student’s t test and, for weekends, White’s test of rank sums). Our aim was to institute a discriminating but flexible system of approval of these requests. A more severe attitude by any staff with authority could reduce further the number processed. After reviewing our experience in this exercise, we believe that, in our district and in microbiology, emergency requests should not be singled out for criticism and for cuts. We agree with you that the attitude of the clinical consultant is crucial in setting the climate in
which laboratory tests are generated. While there is room for education in the discriminating use of some emergency investigations, our on-call requests reflect the climate of clinical endeavour prevailing at all times in the service; when this is curtailed it will be reasonable to expect on-call requests to decline also. We thank the medical and scientific staff and MLSOs who cooperated in this
experiment. Microbiology Department, Bristol Royal Infirmary, Bristol BS2 8HW
G. A. J. HARRISON D. C. E. SPELLER
AN END TO ANTENATAL OESTROGEN MONITORING?
SIR,—The effect of abolishing antenatal oestrogen testing for one (May 26, p 1171) was an apparently unaltered perinatal mortality rate at St George’s Hospital, London. Professor Chard (June 2, p 1236) argues that this outcome might have been fortuitous, that most people gave up urine testing long before 1983, year
and that "the final selection of [antenatal] tests must be based on proper scientific study". It is certainly difficult to refute the chance outcome view. Three years ago I reviewed the urine vs blood oestriol controversy at a meeting of the Association of Clinical Biochemists, concluding that plasma unconjugated oestriol was the better indicator of fetal function and a more up-to-date reflection of fetal oestriol production. So it cannot be successfully argued that stopping antenatal "at risk" testing for plasma oestriol (rather than urine oestrogens) will necessarily result in no harm. On the other hand, experience in East Berkshire’ does prompt me to support the withdrawal of this biochemical service. Since 1979 only two of the four consultant obstetricians in this health district have asked for plasma oestriols and to date there is no evidence that their perinatal mortality rates are better than those of their colleagues who do not request plasma oestriols. As Chard knows, blood human placental lactogen (hPL) is not a true alternative since it reflects placental, not fetoplacental, function. He chose to refer to a controlled trial championing it, rather than to an equally good trial2 revealing that antenatal hPL screening did not improve perinatal outcome. Chard’s point about selecting special biochemical tests scientifically has been authoritatively reasoned and advocated by Holland and Whitehead;3it applies to choice among pathological tests. However, where in-vivo electronic-engineering monitoring devices are proposed as alternatives to in-vitro biochemical testing, it may be impossible and/or unethical to procure statistical proof of superiority. I predicted in May, 1981, in the DHSS Advisory Committee on the Assessment of Laboratory Standards, that advanced ultrasonography and cardiotocography would overtake and supplant plasma oestriol estimations within five years-a development never dreamed of when, eighteen years ago, I had pressed urine oestrogen testing on to my Canadian obstetric colleagues. It looks as though I am not going to be far out. Clinical Biochemistry Department, Wexham Park Hospital.
D. WATSON
Slough, Berkshire 5L2 4HL
1. Simmons SC Feto-placental function tests Lancet 1978; ii: 1096 2 Zlatnik FJ, Varner MW, Hawser KS Human placental lactogen: A 3
predictor of perinatal outcome? Obstet Gynecol 1979, 54: 205-10 Holland WW, Whitehead TP. Value of new laboratory tests in diagnosis and treatment Lancet 1974; ii. 391-94.
MICROWAVE CATARACT IN RADIOLINEMEN AND CONTROLS
SIR,—Microwave irradiation is cataractogenic in laboratory animals. Some studies have shown no excess of cataract in people with possible occupational exposure to microwave irradiation2,3 while others 4,5 have revealed an apparent increase in lens opacities (including posterior subcapsular opacities, PSC) in persons with6 possible occupational microwave exposure. According to Zaret microwave cataract occurs, early in its course, as a PSC. Radio and television broadcasting and repeater towers emit microwaves. Radiolinemen who erect and maintain such for microwave cataract.
towers
could be at risk