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Editorial
Journal of medical screening.
NJ Wald. J Med Screen 1994 1: 1-2.

Comment
Screening for malignant melanoma.
J Morris. J Med Screen 1994 1: 2.

Journal Articles
Accuracy of ultrasound in a screening programme for abdominal aortic aneurysms.
PR Thomas, JC Shaw, HA Ashton, DN Kay, and RA Scott. J Med Screen 1994 1: 3-6.
OBJECTIVES: To assess the accuracy of ultrasound in the measurement of aortic diameter.
SETTING: A general practice based screening programme for abdominal aortic aneurysm.
DESIGN: (a) comparison of ultrasound with computed tomography (CT) measurement; (b) two period crossover study to assess interobserver error; (c) comparison of ultrasound measurements by technicians and radiologists. RESULTS: In 36 patients where CT showed clear maxima in anteroposterior diameter, the measurement by ultrasound was consistently less than by CT scan (mean ultrasound-CT difference -4.4 mm, range -12.3 to 2.4 mm). There was no difference in the measurements made by different ultrasonographers, but their method of measurement produced a reading for aortic diameter less than that obtained by a vascular radiologist.
CONCLUSIONS: These results show that ultrasound measurement is less accurate for smaller aneurysms, consistently gives a smaller reading for aortic diameter when compared with CT measurement, but was reproducible between ultrasonographers. Monitoring and audit of aneurysm screening programmes to assess accuracy and reproducibility of ultrasound measurement is recommended.

Psychological consequences of screening mammography.
J Cockburn, M Staples, SF Hurley, and T De Luise. J Med Screen 1994 1: 7-12.
OBJECTIVE: To examine the psychological consequences at a number of stages in the screening process for women attending a screening mammography programme.
SETTING: A pilot mammographic screening programme in Melbourne, Australia.
METHOD: The psychological consequences questionnaire (PCQ; a reliable and valid measure of the psychological consequences of screening mammography) was used to measure the emotional, social, and physical functioning of women in a mammographic screening programme and a control community sample. A screening group (in whom no abnormality was detected at initial screen; n = 142) had four measurements: at screening clinic; before results were received; one week after all-clear results were received; and eight months after initial visit. The recall group (who were recalled for further investigation which showed the detected abnormality to be benign; n = 58) had measurements at the same points as the screening group and an additional measurement while waiting at the recall assessment clinic. A randomly selected community control group (n = 52) had measurements one week, two weeks, three weeks, and eight months after consenting to participate.
RESULTS: Emotional, social, and physical functioning of women in the screening group did not change over time and at no point differed significantly from that of community controls. The profiles of emotional and physical dysfunction of women in the recall group differed significantly from those of the screening and control groups. The level of emotional and physical dysfunction in the recall group was highest while waiting at recall assessment clinic, and scores were still significantly higher than scores obtained at comparable times from screening and control groups one week after obtaining notification that there was no sign of cancer (emotional P < 0.001; physical P < 0.05). This difference had disappeared eight months after the screening visit, when the level of emotional and physical functioning was similar to that of the screening and control groups. Social dysfunction scores did not change significantly over time and were similar for all three groups.
CONCLUSIONS: Given that up to 10% of women are recalled for further investigations on first round screening, significant numbers of women may have psychological consequences. This speaks for the necessity for accurate reading of mammograms to minimise the false positive recall rate, and for counselling services to be available at recall assessment centres.

Commissioning diabetic eye screening by optometrists: a local initiative at the primary-secondary care interface.
A Harris, C Bonell, T Evans, and G Roberson. J Med Screen 1994 1: 13-15.
The rationale behind the decision of a London family health services authority (Lambeth, Southwark, and Lewisham) to embark on a programme for diabetic eye screening by optometrists is outlined, discussing the way in which the scheme was set up and its possible future development. This family health services authority brought together a range of professionals across primary and secondary care to reach agreement on development of the service, and a consensus on clinical guidelines for operation of the scheme. This was particularly difficult in an area served by four hospitals which provide care to diabetics. Development of the scheme identified key questions about quality which have promoted a separate research agenda.

Preventing manifestations of hereditary haemochromatosis through population based screening.
JE Haddow and TB Ledue. J Med Screen 1994 1: 16-21.
OBJECTIVE: To evaluate the efficacy of identifying presymptomatic hereditary haemochromatosis through population based screening.
DESIGN: Review the hereditary pattern, prevalence, and clinical manifestations of haemochromatosis. Estimate the detection and false positive rates associated with available screening and diagnostic tests. Develop examples of screening protocols and other components that would be necessary for proper implementation. Identify potential barriers and objections.
CONCLUSIONS: Hereditary haemochromatosis, an autosomal recessive disorder with a prevalence of three to five per thousand in the general population, is associated with a wide variety of clinical manifestations, usually beginning in mid to late adult years. Identifying and treating this disorder after symptoms appear can arrest its progress but usually cannot reverse existing damage to joints, liver, pancreas, pituitary gland, and other organs. Measuring transferrin saturation in serum is now known to be a reliable screening test for haemochromatosis when applied to a general population of healthy adults, detecting about 80% of cases, with a 0.3% false positive rate. Liver biopsy with iron staining and total iron concentration is the recommended diagnostic test for subjects with positive screening tests. Treatment with phlebotomy can then prevent manifestations. Effective systematic identification and management of presymptomatic haemochromatosis in the general population is best accomplished within the framework of an organised screening programme. Potential barriers include accessibility of young adult populations and attitudes in the health community that severe clinical manifestations are relatively uncommon. It is recommended that pilot programmes be undertaken to determine the feasibility of introducing screening for haemochromatosis as part of routine health care.

Screening for melanoma and options for its evaluation.
JM Elwood. J Med Screen 1994 1: 22-38.
A review of the published evidence presented here argues that screening for melanoma is recommended and practised at present, but with wide diversity of opinions about its value; there is evidence that screening has considerable potential for benefit, but the evidence of actual benefit is limited; and there are substantial costs and potential hazards from screening. On this basis the evaluation of screening procedures for melanoma is important, and options for this are discussed. The ideal study design to assess the efficacy of melanoma screening in reducing mortality is a large scale randomised trial. This may need a well coordinated proposal involving several centres in one or more countries, and the cost would be substantial. Without such a trial, however, it is most likely that increasing resources will be put into poorly designed screening programmes of unknown value. The simplest and strongest designs use individual randomisation, but group randomisation designs may have practical advantages, though they require a greater sample size. Designs based on general population screening, and on screening only high risk groups, are both considered. They answer different questions. In countries with high incidence the value of general population screening is probably the more critical. Not enough is known to specify the type and frequency of screening precisely; both screening by doctors and self screening require evaluation, and annual screening should probably be tested. The age range at risk will depend on the local incidence, but is likely to be quite wide-for example, 45-69, and both sexes need inclusion. Thus a suggested design for a moderate to high incidence area would be a trial, randomised by individual or group, assessing at least two annual rounds of both screening by doctor and self screening (ideally by a factorial design), for adults aged 45-69, with mortality over several years' follow up as the critical outcome. In an area with good data systems such a study could compare screening offered to some 260,000 subjects with 10 times that number of controls passively followed up, with 90% power to detect a one third reduction in mortality. A general assessment of costs over five years gave estimates of $8.3 million for the screening programme and $2.4 million for the evaluation. The much weaker designs, area based cohort studies using individual data or a simpler ecological comparison, and case-control studies, are also considered. If well designed with attention to their methodological limitations they may be valuable but are unlikely to be as definitive as a randomised trial.

Assessing value for money in medical screening.
JA Cairns and P Shackley. J Med Screen 1994 1: 39-44.

Implementation of an antenatal serum screening programme for Down's syndrome in two districts (Brighton and Eastbourne). The Brighton and Eastbourne Down's Syndrome Screening Group.
M Piggott, P Wilkinson, and J Bennett. J Med Screen 1994 1: 45-49.
OBJECTIVES: To evaluate the introduction to two health districts of an antenatal serum screening programme for Down's syndrome using the triple test-measurement of alpha fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin concentrations in second trimester serum samples.
METHODS: All women delivering at the main maternity units in both districts were eligible for the screening programme. A serum sample was taken between 15 and 22 weeks' gestation, confirmed by ultrasound scan. An estimated risk of 1 in 250 or greater was considered to be a screen positive result and further diagnostic tests were offered. As far as possible the outcome of all screened pregnancies was recorded, and babies with Down's syndrome born to women who declined serum screening were also identified.
RESULTS: 6990 singleton pregnancies were screened over a two year period, representing an estimated uptake of 67% (6990/ 10,443). After a screen positive result 80% of women (168/211; 95% confidence interval 74.2 to 85.1%) opted for amniocentesis. The false positive rate was 2.9% (203/6979; 95% confidence interval 2.5 to 3.3%). The detection rate in the screened population was 73% (8/11). The estimated cost of identifying one Down's syndrome affected pregnancy was about 31,000 pounds.
CONCLUSIONS: Successful introduction of the triple test to health districts where there is no established serum screening programme for neural tube defects is possible. The programme seems to be acceptable to most of those screened. Uptake of the programme is sufficient to make it more effective than a policy for Down's syndrome screening dependent on age only.

Should we screen for growth problems in children? The pragmatic answer for 1994-5.
A Macfarlane. J Med Screen 1994 1: 50-59.

Tumour markers and screening for gastrointestinal cancer: a follow up study in Finland.
M Hakama, UH Stenman, P Knekt, J Jarvisalo, A Leino, T Hakulinen, J Maatela, and A Aromaa. J Med Screen 1994 1: 60-64.
BACKGROUND: Screening for gastrointestinal cancer is based mainly on a barium contrast x ray method and on identification of occult blood in stools. The methods are relatively expensive, not always acceptable to the participants, and there is only limited evidence of their effectiveness in reducing the mortality from gastrointestinal cancer.
OBJECTIVE: To investigate the validity of several tumour markers as a screening test for stomach cancer and for colorectal cancer.
METHODS: A registry of 36,265 serum samples drawn during 1968-72 was linked to the cancer registry. Follow up was during 1968-80 when 94 stomach cancers and 95 colorectal cancers were identified. One to two matched case-control design was applied, and the concentrations of CEA, CA 19-9, CA 50, and TATI were assessed.
RESULTS: The mean values of the markers between the cases and the controls were almost the same for the total material. Case-control differences were found between the 11 sets with an interval of less than one year between drawing the sample and diagnosis of the cancer. The highest validity was found in CEA for colorectal cancer (specificity 91%; sensitivity 64%) and in CA 19-9 for stomach cancer (specificity 74%; sensitivity 73%).
CONCLUSION: CEA, CA 19-9, CA 50, or TATI are not valid screening tests. Case-control differences were found with a potential one year screening interval, but they were not large enough for sufficient validity.

Population based prenatal screening for the fragile X syndrome.
GE Palomaki. J Med Screen 1994 1: 65-72.

Letter
Inadequate follow up for abnormal cervical smears.
A Gambi, N Grilli, F Gentilini, and C Monti. J Med Screen 1994 1: 74.

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