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Editorials
What is case-finding?
NJ Wald and JK Morris. J Med Screen 1996 3: 1.

Should testicular self examination be recommended?
JK Morris. J Med Screen 1996 3: 2.

Journal Articles
Testicular cancer: to screen or not to screen?
SA Buetow. J Med Screen 1996 3: 3-6.
OBJECTIVES - To evaluate the evidence for and against routine testicular cancer screening by primary health care providers and patients (testicular self examination).
SETTING - Low reported frequency of routine screening for testicular cancer attributed to poor knowledge of the disease and how to screen for it.
METHODS - Literature based evaluation of the screening suitability of testicular cancer as a disease and palpation of the testis as the proposed screening test, and of the effectiveness of screening for testicular cancer.
RESULTS - Testicular cancer is not a major public health problem. Its low prevalence makes routine screening cost ineffective. As a screening test for the disease, palpation has high sensitivity but its levels of specificity and positive predictive value are unacceptable. Palpation of the testes has not been shown to reduce mortality or morbidity.
CONCLUSION - There is insufficient evidence to justify routine screening for testicular cancer by health care providers and patients. This lack of evidence may better explain the low reported levels of screening than can ignorance of the evidence available.

Early mortality and morbidity in children with Down's syndrome diagnosed in two regional health authorities in 1989.
ME Brookes and E Alberman. J Med Screen 1996 3: 7-11.
OBJECTIVES - To assess the risk of early mortality and the quality of health of a recent cohort of 5 year old children with Down's syndrome to provide current information on prognosis.
SETTING - A follow up study in 1994 of all live births with a cytogenetic diagnosis of trisomy 21 or related karyotype born in 1989 and diagnosed in the South East Thames and Oxford Regional Health Authorities; these amounted to 100 children.
RESULTS - Eighteen of the sample of 100 had died in the first three years, and seven were reported as adopted. Fifty six mothers were interviewed, including five of children who had died. High rates of associated congenital defects were reported. The most common were congenital heart defects, which were reported for 29 of the 69 children for whom health information was available, and were certified as the underlying cause of death of 12 and required surgery in 11. At least five children had had gastrointestinal atresia or other gut blockage, most presenting at birth but one case occurring at 3 years, and these had necessitated a colostomy in two cases. Leukaemia had occurred in two children, both of whom had died. As expected mothers also reported high rates of defects of hearing, often treated with grommets; of vision; and frequent severe infections.
CONCLUSIONS - Information of this nature, as well as that regarding the more positive aspects of Down's syndrome, should be made available to those counselling parents considering the offer of diagnostic tests

Can reliable Down's syndrome detection rates be determined from prenatal screening intervention trials?
GE Palomaki, LM Neveux, and JE Haddow. J Med Screen 1996 3: 12-17.
OBJECTIVES - To develop a standardised approach for analysing Down's syndrome screening performance in clinical practice and to apply it to published intervention trials in order to estimate detection and false positive rates more accurately.
METHODS - Peer reviewed intervention trials, grouped by specific combination of analytes, were reanalysed. Revised detection rates were calculated for each study, taking into account both the high spontaneous loss during the last half of pregnancy and the possible under ascertainment of Down's syndrome live births not detected by screening. Collective screening performance was estimated, when possible, using a published methodology based on fitting receiver-operator characteristic curves.
RESULTS - Sixteen trials were analysed; 11 using three, and five using two, analytes. Collective screening performance for the triple analyte trials was Down's syndrome detection rates of 57, 64, and 69% at amniocentesis referral rates of 3, 5, and 7% respectively. Four of the five studies involving two analytes performed less well, individually, when compared with the overall performance of the three analyte studies. It was not possible to estimate collective performance for the two analyte studies because there were too few.
CONCLUSIONS - Accurate Down's syndrome detection rates are difficult to obtain in intervention trials owing to two potential biases, both of which tend to produce overestimates of the true rates. These sources of bias need to be taken into account when analysing and reporting Down's syndrome intervention trials. The methodology presented here offers the opportunity to achieve a more reliable, standardised estimate of both individual and collective intervention trial screening performance.

Comparison of radiographer/radiologist double film reading with single reading in breast cancer screening.
R Pauli, S Hammond, J Cooke, and J Ansell. J Med Screen 1996 3: 18-22.
OBJECTIVES - To assess the efficacy of dual film reading in screening mammography with a suitably trained radiographer as the second reader and to determine a suitable decision model for radiographer/radiologist double reading.
SETTING - Three breast screening centres in South Thames (West) region.
METHODS - Seven radiographers with prior film reading training double read 17 202 screening mammograms with a radiologist. Screening performance of radiographers and radiologists was assessed taking into account interval cancers. The efficacy of radiographer/radiologist double reading was assessed in terms of changes in sensitivity and specificity compared with radiologist single reading.
RESULTS - Radiographers yielded equivalent sensitivity but lower specificity than radiologist film readers. The effect of double reading between radiographer/radiologist pairs was an increase in sensitivity of 6-4%, which was achieved at the cost of a 0-6% decrease in specificity. This was reached by a decision system involving radiologists' review of radiographer queries and recall classifications. If all radiographer queries were recalled a large increase in sensitivity would be counterbalanced by an equally large decrease in specificity.
CONCLUSIONS - Radiographer/radiologist double reading resulted in similar increases in sensitivity as those previously reported in radiologist double reading studies. Radiologist review of radiographer reported abnormalities is a suitable means by which to limit excess recall.

Invasive cervical cancer in Southampton and South West Hampshire: effect of introducing a comprehensive screening programme.
A Herbert, C Breen, TN Bryant, A Hitchcock, H Macdonald, GH Millward-Sadler, and J Smith. J Med Screen 1996 3: 23-28.
A study of invasive cervical cancer in Southampton and South West Hampshire is reported, covering three consecutive three year periods during which the screening coverage increased from an estimated 60% to a recorded 87% of eligible women aged 20-64. From the first to the third periods of the study in that age group registrations of fully invasive squamous cell carcinoma (stage lb and above) fell from 64 to 30 (53%), which was largely counteracted by an increase in microinvasive squamous cell carcinoma (linear trend: P<0.0001). In the same age group registrations of adenocarcinoma rose slightly, which resulted from an increase in the number diagnosed at a depth of invasion of less than 3 mm. There were no significant changes in the numbers of stage III and IV cancers or among cancers in women aged 65 and over. A strong inverse association was found between stage of both histological types of cancer and their likelihood of being screen detected rather than symptomatic: 91% of screen detected cancers were diagnosed at stage I compared with 38% of symptomatic cancers. There was a slight downward trend in the incidence of cancer per 100,000 total female population across the three periods of the study with a significant trend towards low stage disease, which is likely to reduce mortality in years to come. The trend towards screen detected cancers and cancers of less than 3 mm depth of invasion is presented as a positive outcome to be expected in early rounds of increasing the screening coverage.

Consequences of current patterns of Pap smear and colposcopy use.
AM Kavanagh, G Santow, and H Mitchell. J Med Screen 1996 3: 29-34.
OBJECTIVES - To describe age specific frequencies of Pap smear and colposcopy use in the Australian Capital Territory (ACT) and to estimate the cumulative effects of current patterns of use.
SETTING - Frequencies of Pap smear and colposcopy use were estimated for the financial year from 1 July 1989 to 30 June 1990. Eligible women were between the ages of 15 and 74, living in the ACT.
METHODS - Data collected from a 10% sample of subjects enrolled with Medicare and from the only public pathology laboratory in the ACT were used to estimate age specific frequencies. The expected number of deaths from cervical cancer in the ACT in the absence of a screening programme was estimated by applying Australian age specific mortality rates for cervical cancer between 1960 and 1964 to the 1989 ACT population. A life table approach was used to simulate the cumulative risk of colposcopy - given current age specific rates - on a hypothetical cohort of 1000, 15 year old women.
RESULTS - Forty four per cent (95% confidence interval (CI) 42.9 to 44.9) of women had a Pap smear and 2.5% had colposcopy (95% CI 2.4 to 2.6). Two and a half percent of 15 to 24 year old women had colposcopy (95% CI 1.9 to 3.1). The ratio of women having Pap smears to women having colposcopy was 17-8:1 (95% CI 17.7 to 17.9). An estimated 247 women had colposcopy for every cervical cancer death; in the 15 to 24 year old age group this ratio was 47900:1. A 15 year old woman exposed to current rates of colposcopy (adjusted for hysterectomy) has a 76.8% chance of having a colposcopy during her life time.
CONCLUSIONS - Many more women will have colposcopy than will develop cervical cancer, which undermines the cost effectiveness of Australia's cervical cancer screening programme.

Uptake of cervical screening in general practice: effect of practice organisation, structure, and deprivation.
T Ibbotson, S Wyke, J McEwen, S Macintyre, and M Kelly. J Med Screen 1996 3: 35-39.
OBJECTIVES - To investigate associations between uptake for cervical screening in general practice and the organisation of screening, features of practice structure, and deprivation.
SETTING - Greater Glasgow Health Board area in the west of Scotland, which covers a socioeconomically varied population.
METHODS - General practice questionnaire survey and interview based study. The main outcome measure was the uptake rate for each participating practice over the five and a half years ending 31 December 1993. This was used to determine whether practices achieved 80% uptake to trigger maximum payment for cervical screening services.
RESULTS - Forty seven percent (n = 92) of all practices in the Greater Glasgow Health Board area agreed to take part in the research, with complete data collected for 87 practices. Participation varied according to number of partners in the practice and the average deprivation score of the practice. Uptake rates ranged from 48-2% to 92-9% (median 77.5%, interquartile range 69.8% to 83.4%). Thirty seven practices (43%) achieved the 80% target. None of the recommended features of good organisation of cervical screening showed any statistically significant association with uptake rates. In stepwise multiple regression four variables were shown to have independent associations with uptake. These were the number of partners in the practice, the average deprivation of the practice, the presence of a female general practitioner, and using a practice's own lists for sending out letters of invitation. In stepwise logistic regression just two of these variables contributed to the prediction of achieving 80% uptake namely, average deprivation and number of partners. There were no significant interactions between deprivation and the organisation of screening in relation to uptake.
CONCLUSIONS - Organising cervical screening in general practice according to accepted standards is less important in predicting uptake than more intractable features of the practice such as the size of the partnership, its average deprivation level, the presence of a female general practitioner, and using their own (presumed more accurate) register of addresses to call women. A flexible incentive scheme may more fairly reward the efforts of those general practitioners who achieve high uptake rates but who do not trigger remuneration at the 80% level.

CA 125 as a screening test for ovarian cancer.
M Hakama, UH Stenman, P Knekt, J Jarvisalo, T Hakulinen, J Maatela, and A Aromaa. J Med Screen 1996 3: 40-42.
BACKGROUND - Screening for ovarian cancer is based on ultrasound, colour Doppler, and tumour markers. There is only limited evidence on their discriminatory performance and no evidence on their effectiveness in reducing mortality.
OBJECTIVE - To investigate the discriminatory performance of CA 125 as a screening test for ovarian cancer.
METHODS - A registry of 15 093 serum samples drawn in 1968-72 was linked to the cancer registry. During follow up between 1968 and 1980 24 ovarian cancers were identified. One or two matched case-control design nested within the sample bank was applied and the concentrations of CA 125 were assessed.
RESULTS - Case-control differences (relative risk 4-0, 95% confidence interval 1.0 to 15.5 at 20 kU/1) were found. Detection rate of the CA 125 test was 21-33% and the true negative rate was 75-98% depending on the cut off level and interval between drawing of the blood sample and diagnosis of the cancer.
CONCLUSION - CA 125 is not a valid screening test if used alone. Case-control differences of borderline significance were found in CA 125 before diagnosis of ovarian cancer, but they were not large enough to provide a sufficient detection rate.

Screening for melanoma by primary health care physicians: a cost-effectiveness analysis.
A Girgis, P Clarke, RC Burton, and RW Sanson-Fisher. J Med Screen 1996 3: 47-53.
BACKGROUND AND DESIGN - Australia has the highest rates of skin cancer in the world, and the incidence is estimated to be doubling every 10 years. Despite advances in the early detection and treatment of melanoma about 800 people still die nationally of the disease each year. A possible strategy for further reducing the mortality from melanoma is an organised programme of population screening for unsuspected lesions in asymptomatic people. Arguments against introducing melanoma screening have been based on cost and the lack of reliable data on the efficacy of any screening tests. To date, however, there has been no systematic economic assessment of the cost effectiveness of melanoma screening. The purpose of this research was to determine whether screening may be potentially cost effective and, therefore, warrants further investigation. A computer was used to simulate the effects of a hypothetical melanoma screening programme that was in operation for 20 years, using cohorts of Australians aged 50 at the start of the programme. Based on this simulation, cost-effectiveness estimates of melanoma screening were calculated.
RESULTS - Under the standard assumptions used in the model, and setting the sensitivity of the screening test (visual inspection of the skin) at 60%, cost effectiveness ranged from Aust$6853 per life year saved for men if screening was undertaken five yearly to $12 137 if screening was two yearly. For women, it ranged from $11 102 for five yearly screening to $20 877 for two yearly screening.
CONCLUSION - The analysis suggests that a melanoma screening programme could be cost effective, particularly if five yearly screening is implemented by family practitioners for men over the age of 50.

Clinical Trial
Hospital based screening of 65-73 year old men for abdominal aortic aneurysms in the county of Viborg, Denmark.
JS Lindholt, EW Henneberg, H Fasting, and S Juul. J Med Screen 1996 3: 43-46.
OBJECTIVE - To analyse the benefits of screening older men for abdominal aortic aneurysms.
METHODS - A hospital based screening trial concerning 13 500 65-73 year old men using B-mode ultrasonographic scanning. To improve the response rate the invited men could change their appointment, and nonresponders were reinvited.
RESULTS - Results from the first year of the trial are presented. Among 4404 invited, 3344 (76%) were scanned. The primary response rate was 64.8%, but a further 11.2% were scanned after revised appointments or reinvitation. The whole infrarenal aorta could be visualised in 97-6%, and the distal part in 99.7% of the scans. The time taken for each scan was 9-7 minutes and the costs per scan were $9.50. One hundred and fifty three subjects (4.6%) had aortic diameters of 25-29 min, and 141 (4.2%) had an abdominal aortic aneurysm, 19 (0.6%) above 49 mm in diameter.
CONCLUSION - In Denmark the short term costs and benefits of screening older men for abdominal aortic aneurysms seem realistic. Long term costs and benefits need to be investigated.

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