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Editorials
The risk figure of 1/270.
AE Donnenfeld. J Med Screen 1995 2: 1-2.

Information leaflets.
AJ Smith. J Med Screen 1995 2: 3-4.

Journal Articles
Is psychological wellbeing impaired in long-term survivors of breast cancer?
R Ellman and BA Thomas. J Med Screen 1995 2: 5-9.
OBJECTIVE--To measure anxiety and depression in long term survivors of breast cancer.
DESIGN--Case-control study.
SETTING--Follow up of the trial of early detection of breast cancer in the South West Surrey Health District.
SUBJECTS--331 patients with breast cancer aged 50-78, attending mammographic follow up, who had been invited to screening before diagnosis, and 584 controls who had attended the same clinic but did not have breast cancer. The sample included 290 pairs matched by screening attendance pattern and year of birth.
MAIN OUTCOME MEASURE--Anxiety and depression scores on the Hospital Anxiety and Depression Scale.
RESULTS--Significantly fewer symptoms of anxiety and depression were reported by patients with cancer than by controls and significantly fewer had high scores suggesting the presence of psychological morbidity meriting treatment. Among the patients with cancer anxiety was more common at the first annual follow up than at later visits. Symptom scores were not significantly related to the manner of detection or to the type of initial treatment. Potentially confounding social and personal factors did not account for the differences between patients with cancer and controls.
CONCLUSION--The prevalence of anxiety and depression is not increased in long term survivors of breast cancer who are apparently free from disease and is not substantially affected by the manner in which a cancer is detected or by the treatment given. In the light of these findings it is difficult to justify large "quality adjustments" to the estimates of recurrence-free years of life saved by screening. Those who counsel patients with breast cancer should be aware that although the initial distress can be severe, meriting psychological treatment, patients do recover their normal ability to enjoy life.

Revision of "NHS breast screening: the facts": an evaluation.
J Patnick, J Austoker, and T Wolff. J Med Screen 1995 2: 15-17.

Prenatal sonographic detection of isolated fetal choroid plexus cysts: should we screen for trisomy 18?
AE Donnenfeld. J Med Screen 1995 2: 18-21.
It has been established that the finding of a fetal choroid plexus cyst confers an increased risk of aneuploidy, predominantly trisomy 18. In view of this association many investigators have advocated amniocentesis when a choroid plexus cyst is identified by prenatal ultrasonography. A risk/benefit and economic analysis of such a policy is presented. When the following factors are taken into account-published data on the frequency of isolated choroid plexus cysts in second trimester fetuses, the risk of trisomy 18 in these fetuses, the population frequency of trisomy 18, the natural history and prognosis for these infants, and the risks and cost of amniocentesis--it is concluded that performing amniocentesis on second trimester fetuses with choroid plexus cysts is neither cost effective nor beneficial. For the detection of one infant with trisomy 18 that will survive past five months, 25 normal fetuses would be lost owing to amniocentesis. Identification of trisomy 18 by determining the presence of choroid plexus cysts in fetuses is not a worthwhile screening policy.

Cost comparison of different methods of screening for cystic fibrosis.
JK Morris and PM Oppenheimer. J Med Screen 1995 2: 22-27.
OBJECTIVE--To compare the costs of several proposed methods of screening for cystic fibrosis.
SETTING--England and Wales.
METHODS--The costs of screening carried out at hospital antenatal clinics, general practitioner (GP) antenatal consultations, GP surgeries, and at work were estimated using data from demonstration projects. Couple screening, stepwise screening, and screening of individuals were considered.
RESULTS--Couple screening at antenatal hospital clinics was the least expensive per carrier couple detected, amounting to 35,700 pounds (142,900 pounds for each potential cystic fibrosis fetus detected). The costs of the reagents (25 pounds per test) accounted for over 60% of this total.
CONCLUSIONS--Antenatal screening, in addition to being the most cost effective method of screening, is also medically the screening method of choice as it provides information at the latest time when effective preventive action can be taken and at a time when all people to be screened are likely to be accessible. If the costs of the reagents could be reduced to 5 pounds (still higher than the costs of most diagnostic reagents) the cost for each pregnant carrier couple offered screening would be reduced by 50% to about 18,000 pounds, and the cost of offering screening to 684,000 pregnant couples in England and Wales would be about 9 1/2 m instead of 19 m pounds.

Effect of parity on human chorionic gonadotrophin levels and Down's syndrome screening.
JE Haddow, GE Palomaki, and GJ Knight. J Med Screen 1995 2: 28-30.
OBJECTIVE--To investigate further the association between parity and human chorionic gonadotrophin (hCG) levels during the second trimester and determine whether prenatal screening for Down's syndrome might be made more efficient by adjusting for this variable.
METHODS--Measurements of hCG were analysed in relation to parity from a cohort of 16,675 singleton pregnancies with viable outcomes, and from 108 singleton pregnancies affected by Down's syndrome. Cigarette smoking during pregnancy and maternal age were also analysed in relation to hCG levels.
RESULTS--For both unaffected pregnancies and pregnancies with Down's syndrome the median hCG levels were 7% lower in parous than in nulliparous women. A dose-response relation was also documented for the unaffected pregnancies. When para 0, para 1, and para 2 women were studied separately, hCG levels rose steadily as age advanced. Adjusting hCG levels for parity led to a 0.1% reduction in variance of the distribution of hCG measurements in unaffected pregnancies and to a negligible increase in Down's syndrome screening efficiency.
CONCLUSION--The effect of parity is not sufficiently great to warrant routine adjustment of hCG levels as part of prenatal screening for Down's syndrome.

Construction of a community height surveillance programme: the Hackney growth initiative.
S Hearn, AM Cotterill, W Majrowski, C Rohan, S Jenkins, and MO Savage. J Med Screen 1995 2: 31-34.
OBJECTIVES--To determine why, in the London Borough of Hackney before 1990, fewer children than expected were identified with remedial causes of short stature. To construct a practical model for height surveillance of 5 and 11 year old school entrants to improve the quality of child growth surveillance.
SETTING--City and Hackney Borough, London, United Kingdom.
METHODS--School nurses were trained by a clinical auxologist to measure children's height at school entry accurately and reproducibly. New procedures for measurement technique, plotting of data, referral, and audit were established. A reference manual was provided and a continuing training programme was started.
RESULTS--During the first year the percentage of the target group measured was low. Changes in work practice led to improvements from 77% measured in the first year to 91% in the second year and 87% in the third year for 5 year olds. Improvements for 11 year olds were from 36% to 86% to 87% over the three years. Only 1.2% of 5 year olds and 2.6% of 11 year olds measured had height less than the third centile (compared with Tanner's height standards).
CONCLUSIONS--School nurses measured height reliably. New audit procedures led to rapid changes in working practice and improvements in the percentage of children measured. The low numbers of short children previously identified with unrecognised abnormality may indicate an upward trend in height in this inner city population.

How much paediatric HIV infection could be prevented by antenatal HIV testing?
DT Dunn, A Nicoll, FJ Holland, and CF Davison. J Med Screen 1995 2: 35-40.
OBJECTIVE--To estimate the reduction in the number of children infected with HIV that might be achieved by extending the provision of voluntary antenatal HIV testing. This effect would be mediated by increased numbers of women infected with HIV who receive an intervention to reduce the risk of vertical transmission (for example, zidovudine or caesarean section delivery), who use an alternative to breast feeding, or whose pregnancy is terminated.
SETTING--London, United Kingdom.
METHODS--Relevant data were derived from neonatal seroprevalence studies, obstetric and paediatric reporting schemes, and review of external information. Sensitivity analyses were performed for certain parameters.
RESULTS--Of 106,000 births annually in London, an estimated 169 are to women infected with HIV whose infection is not currently recognised before pregnancy. An estimated 28-33 children born to these women will be infected. Precise prediction of the number of paediatric HIV infections that could be prevented is difficult because of uncertainty in certain factors, particularly the uptake of antenatal testing and the efficacy and acceptability of interventions to reduce prenatal or perinatal transmission. If a testing programme detected 70% of infected women, none of whom opted for a termination but all of whom exclusively bottle fed and received an intervention which halved the risk of transmission, about 12-16 (42-46%) paediatric HIV infections would be prevented annually.
CONCLUSIONS--The estimated cost of preventing each paediatric infection is high, but this should be seen in the context of the lifetime health and social care costs for a child infected with HIV. The feasibility of selective testing should be considered when formulating policies on antenatal HIV testing. Programmes that are introduced should be audited to obtain better estimates of costs and benefits.

Suggested screening guidelines for familial colorectal cancer.
SV Hodgson, DT Bishop, MG Dunlop, DG Evans, and JM Northover. J Med Screen 1995 2: 45-51.
Guidelines for screening for colorectal cancer in subjects with a positive family history of the disease, without the use of DNA based screening, are outlined. These suggestions are derived from (a) the experience of screening 644 subjects at an estimated lifetime risk of dying from colorectal cancer of 10% or more, in the St Mark's Family Cancer Clinic, over six years, and (b) a review of published studies, particularly incorporating the experience of the International Collaboration Group on Hereditary Non-polyposis Colorectal Cancer (HNPCC). Selection of subjects for surveillance depends upon the empirical evaluation of their risk of colorectal cancer, based upon family history details, with the exclusion of a diagnosis of familial adenomatous polyposis in the family. When DNA predictive tests for genes predisposing to HNPCC are available, surveillance can be directed at subjects with a germline mutation known to confer an increased genetic risk of colorectal cancer and discontinued in those at lower (or average) risk. In many subjects, however, DNA testing may still not be possible because of the failure to identify a predisposing mutation in an affected subject in their family. Any surveillance protocol can only be evaluated by long term follow up of those subjects in multiple centres.

The human element in medical screening.
D Laming. J Med Screen 1995 2: 52-55.
An explanation is offered for the reasons why an experienced pathologist engaged in the screening of cervical smears should have issued a large number of false negative diagnoses. The explanation centres on the interactions which occur between successive judgments when a long sequence of similar stimuli are inspected. Briefly, those interactions have the character of an assimilation of each judgment to its predecessor, and the resultant process is capable of "running away". A procedure is suggested, in which the provision of immediate knowledge of results for a small proportion of the smears inspected would prevent such systematic misdiagnoses from recurring in the future. The implications of this natural experiment for medical screening in general are spelt out.

Clinical Trials
Effect of breast cancer screening after age 65.
HH Chen, L Tabar, G Fagerberg, and SW Duffy. J Med Screen 1995 2: 10-14.
OBJECTIVE--To assess the effect of mammographic screening for breast cancer in women aged 65 years or over.
SETTING--The Swedish two county trial of screening for breast cancer, in which 77,080 women aged 40-74 (21,925 aged 65-74) were randomly allocated to receive regular mammographic screening for breast cancer, and 55,985 women aged 40-74 (15,344 aged 65-74) were allocated to an unscreened control group.
METHODS--One group was screened every 33 months on average, except for those aged 40-49 at randomisation who were screened every 24 months. The control group was screened once at the conclusion of the trial. The main statistical analysis was the comparison of cumulative mortality with 13 years of follow up between the screened and control groups, in age groups 50-64 and 65-74, using Poisson regression. This was complemented by subsidiary analyses assessing the lead time, sensitivity, and predicted mortality from the size, node status, and grade of tumours diagnosed in the screened and control groups.
RESULTS--In the age group 65-74 at randomisation there was a significant reduction in breast cancer mortality in the screened group, with a relative mortality of 0.68 and 95% confidence interval of 0.51 to 0.89. This was backed up by the results of the analyses of lead time, sensitivity, and tumour characteristics.
CONCLUSIONS--Women aged 65 or more who are regularly screened can expect a reduced risk of dying from breast cancer.

Effect of retesting with dietary restriction in Haemoccult screening for colorectal cancer.
MH Robinson, SM Moss, JD Hardcastle, DK Whynes, JO Chamberlain, and CM Mangham. J Med Screen 1995 2: 41-44.
OBJECTIVES--To determine the detection rate, false positive and false negative rates associated with a policy of retesting with dietary restriction after an initial positive Haemoccult screening test for colorectal cancer, in order to compare the cost effectiveness of such a policy with the alternative, in which all subjects with a positive test would proceed directly to diagnostic colonoscopy.
METHODS--Over four years in a large randomised control trial in Nottingham 35,260 subjects had a mean of 1.5 screening rounds each at two-yearly intervals, and were followed up for a minimum of 27 months. During this period subjects with positive screening tests were asked to repeat the test with dietary restrictions. Estimates of costs of the initial screening and of diagnostic colonoscopy were used to estimate the cost for each cancer detected by the different policies.
RESULTS--1209 subjects had a positive initial screening test and 1033 (85.4%) completed the retests. Four hundred and ninety nine subjects were investigated and 89 cancers detected. In the 710 subjects with negative retests six interval cancers were diagnosed in the two years after screening. If these had been detected by screening under a policy of immediate colonoscopy, test sensitivity would have been improved from 53.6% to 57.2% (P = 0.02), but the cost for each cancer detected would have increased from pound 773 to pound 1509.
CONCLUSION--Retesting with dietary restrictions reduces costs and maximises the benefit of limited colonoscopy resources, but results in a small but significant reduction in test sensitivity compared with a policy for immediate colonoscopy.

Letters
Survival and interim end points in breast cancer.
NE Day, SW Duffy, and HH Chen. J Med Screen 1995 2: 57-58.

Is screening for ovarian cancer worthwhile?
MP Vessey. J Med Screen 1995 2: 57.

Cervical smears: protection or prediction?
B Arroll. J Med Screen 1995 2: 57.

Opportunistic screening for abdominal aortic aneurysm.
M Lewis, P Hoddinott, and A Jackson. J Med Screen 1995 2: 58-59.

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