Showing papers on "Mass screening published in 1985"

Prevalence of Parkinson's disease in the biracial population of Copiah County, Mississippi

Abstract: A door-to-door survey of major neurologic disorders was conducted in the essentially biracial population of Copiah County, MS, using a pretested screening questionnaire. All those suspected of having Parkinson's disease were requested to have a neurologic examination by board-certified neurologists. The study also included those living in institutions. The prevalence of Parkinson's disease (age 40+) was 347 per 100,000 inhabitants. No substantial differences in the age-adjusted prevalence ratios by race or by sex were found in the population studied. Age-specific prevalence ratios for Parkinson's disease increase with advancing age. Over 40% of identified cases were newly diagnosed during the study.

Evaluation of screening programmes for gynaecological cancer

Abstract: A workshop of the Project on Evaluation of Screening Programmes of the International Union against Cancer (UICC) was held in Lyon, France on November 20-22, 1984 The focus of the workshop was on screening for gynaecological cancer, especially for cancer of the cervix uteri This report summarizes the presentations, conclusions and recommendations from the workshop

Selection, follow-up, and analysis in the Health Insurance Plan Study: a randomized trial with breast cancer screening.

Abstract: Critical decisions made 20 years ago by those who planned the randomized trial at the Health Insurance Plan (HIP) of Greater New York to determine the efficacy of periodic screening for breast cancer are detailed. These decisions affected the age group to be screened, screening modalities, frequency of screening, sample size, primary measures for testing efficacy, and period of follow-up (long term). Results of follow-up, 16 years after entry, indicate that mortality due to breast cancer continues to be lower among study women than controls. Numerically, the differential has been stable; relatively, it has decreased. It is estimated that the study group would have experienced about a 30% reduction in breast cancer mortality if screening had been maintained. Relative case survival rates over a 14-year period after diagnosis show changes in contours of trend lines that result from screening. The study group's trend is slightly concave in contrast to the usual convex curve for the controls. The contour of the curve is more decidedly concave among subjects detected through mammography alone than for other subgroups detected through screening, although the relative survival rate remains highest in the mammography only group. Uncertainty persists about effects of screening in the HIP study on breast cancer mortality among women aged 40-49 years at entry.

Age- and sex-specific prevalence of scoliosis and the value of school screening programs.

Abstract: A prevalence study of idiopathic scoliosis was conducted among 29,195 children of a community health district in the province of Quebec. The study was designed to determine whether a permanent screening program for idiopathic scoliosis was justified. The prevalence of the condition among school children aged 8 to 15 years was 42.0 per 1,000 in the screened population, 51.9 per 1,000 among girls, and 32.0 per 1,000 among boys. The positive predictive value of the bending test is estimated as 42.8 per cent for scolioses of 5 degrees or more; it is only 6.4 per cent when curves of 15 degrees or more are considered. The average cost of finding one child with a scoliosis of 5 degrees or more is $194. Mass screening for idiopathic scoliosis does not seem to be justified in the present state of knowledge of the disease.

Relationship between the diagnosis of epithelial abnormalities and the composition of cervical smears.

Abstract: The significance of endocervical columnar cells as a high-quality parameter of cervical smears was studied. In a cohort of women with two successive screenings, the consistency of the cellular composition of the cervical smears and the relation between the cellular composition of the smears and the frequency of the diagnosis of abnormal epithelial changes was investigated. At the first screening, a significantly higher number of epithelial abnormalities was found in smears with endocervical columnar cells than in smears without endocervical columnar cells. A significantly higher number of abnormal epithelial changes was found on the second screening in smears from women whose smears from the first screening did not contain endocervical columnar cells than in smears from women whose smears from the first screening did contain endocervical columnar cells. The presence of endocervical cells should be considered a very important indicator of the quality of cervical smears. The chance of missing an abnormal epithelial change is increased in smears without endocervical columnar cells. When endocervical columnar cells are absent, the smear should be considered to be of unreliable quality and a repeat smear should be taken after a short interval, unless the absence of columnar cells can be satisfactorily explained.

Estimating the sensitivity of a screening test.

Abstract: A commonly used estimate of a screening test's sensitivity, based on the prevalence at screening and the incidence of interval cancers, is shown to be logically unsound and quantitatively poor. An alternative simple estimate is proposed, based only on incidence rates.

A case-control study of cervical cancer screening in north east Scotland.

Abstract: To estimate the relative risk of invasive cervical cancer in each succeeding year after a negative screening result the screening records of all women tested in the north east of Scotland were examined as the basis for a case-control study. The cases consisted of 115 women in whom invasive cervical cancer had been diagnosed in 1968-82 and who had appeared in the screening records at least once before diagnosis. For each patient five controls were selected from women of the same age who appeared in the screening records before the date of diagnosis in the patient. If the patient's cancer had been detected by screening the controls were chosen from women of the same age screened the same year. A comparison was made between cases and controls of the number of negative smears taken before the diagnosis. The results showed a high relative protection (inverse of the relative risk) in the first two years after a negative test, falling steadily as time since the last negative test elapsed. Even after 10 years, however, a considerable residual effect was observed.

Screening for congenital hypothyroidism with specimen collection at two time periods: Results of the Northwest Regional Screening Program

Abstract: To determine the benefit of collecting two routine specimens to test for congenital hypothyroidism, we examined the results of our newborn screening program during the last 9.5 years. The Northwest Regional Screening Program (NWRSP) performs a primary thyroxine test with thyroid-stimulating hormone determinations on the lowest 10% of dried blood filter paper specimens. An initial specimen is obtained in the newborn period, and a routine second specimen is collected at approximately 4 to 6 weeks of age in all infants born in Oregon and 25% of infants born in Idaho, Montana, Alaska, and Nevada. Between May 1975 and October 1984, 182 infants with primary hypothyroidism were detected from 811,917 infants screened, a prevalence rate of 1:4,461. The routine second specimen led to the diagnosis of 19 infants of 484,604 infants screened, a detection rate of 1:25,505. When infants detected by the second screen were compared with those detected by the first screen, they had higher thyroxine and lower thyroid-stimulating hormone concentrations on filter paper and serum specimens. When thyroid scanning was used, all but one infant detected by the second screen had some residual thyroid tissue, whereas 35% of infants detected by the first screen had thyroid aplasia. Skeletal maturation was more likely to be normal in infants detected by the second screen. These infants appear to have milder hypothyroidism due to a later age of onset or slower evolution of thyroid failure. At a cost of $31,881 per infant detected by the second screen, the NWRSP found it cost-effective to obtain a routine second specimen.

Effects of repeated mammographic screening on breast cancer stage distribution. Results from a randomised study of 92 934 women in a Swedish county.

Abstract: A randomised controlled trial of mass screening for breast cancer by single-view mammography was begun in Sweden in 1977. All women aged 40 and older and resident in the counties of Kopparberg and Ostergotland were enrolled. The present report is confined to the Ostergotland study, which started in 1978 and comprised 92934 women. After randomisation, which was done on the basis of communities rather than individuals, 47001 women were allocated to the study group and offered repeated mammographic screening; 45933 were allocated to the control group. As compliance among women over 74 years of age was poor these were excluded from the present report. The yearly incidence of stage II or more advanced breast cancers after the initial screening round up to and including the second was reduced by 40 per cent in the study group compared with the controls. This effect was less marked in the age group 40–49. After 5.5 years average from the date of entry the absolute number of women with stage II-IV disease in the ...

Moire topography in scoliosis. Its accuracy in detecting the site and size of the curve

Abstract: Moire topography was added to school scoliosis screening in Singapore in 1982. The results from 1342 topographs, assessed in isolation, were used to study the accuracy of the method in predicting the radiographic location and magnitude of scoliotic curves. Accuracy in identifying the site of the curve was 68% in the thoracic spine, 54% in the thoracolumbar spine, and 15% in the lumbar region. There were 12.7% false-positive results and 4.3% false negatives. Of patients with a deviation of one moire fringe, 76.5% had a curve of 15 degrees or less; of those with a deviation of four moire fringes, 69% had a curve greater than 26 degrees. The prediction of the Cobb angle was less accurate when there was a deviation of two or three fringes. It is suggested that moire topography as a screening device should be reserved for use in the second tier of screening, since the forward-bending test is an effective and cheap method for the first tier of a mass school-screening programme.

Efficacy of screening for gestational diabetes.

Abstract: A cost analysis of glucose screening was studied prospectively in 434 patients. All patients underwent a 50-gm oral glucose load followed by a 1-hour plasma glucose screen test at 28 weeks (+/- 2 weeks). Patients with a screen test greater than or equal to 130 mg/dl plasma glucose were further tested with an oral glucose tolerance test. Also, previously described clinical risk factors for diabetes were documented on all patients. A 3.3% prevalence of gestational diabetes was found in 178 patients with risk factors, compared with 2.4% of 256 patients without risk factors, not a significant difference. Ten of the 12 gestational diabetics were at least 24 years old, so that screening only this subgroup would still retain a good sensitivity (83%) but at half the cost of universal screening. Screening on the basis of risk factors other than age is inefficient. Though testing only patients who are 24 years of age or older is more cost effective than universal screening, an individual decision must be made regarding its reduced sensitivity.

Hepatitis B in Wisconsin male prisoners: considerations for serologic screening and vaccination.

Abstract: To develop a protocol for prevention of hepatitis B virus (HBV) transmission in Wisconsin prisons, we interviewed 619 male prisoners at incarceration to obtain information on hepatitis B risk factors. We defined previous infections by the presence of hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), or antibody to hepatitis B core antigen (anti-HBc). Logistic regression was used to develop a model of relative risk (RR) of HBV infection. Use of illicit intravenous (IV) drugs was the most important risk factor because of a high prevalence of IV drug use and an RR which ranged from 2.93-7.47. Other important risk factors were: prior hepatitis or jaundice (RR = 6.28), race (RR = 2.54 for Blacks, RR = 3.28 for Latinos), transfusion (RR = 3.00), and age. Previous imprisonment was not an independent risk factor for HBV, hence selective serologic screening and vaccination of prisoners are justified rather than mass screening and vaccination. Based upon prevalence of hepatitis B markers in subgroups, it is necessary to screen prisoners with prior hepatitis or jaundice, prior transfusion, and users of IV drugs. The identification of HBsAg carriers by such screening could prevent infection of "household" contacts. Users of IV drugs who are susceptible to HBV infection should be vaccinated. The remaining prisoners constitute a low-risk group for HBV infection and do not require serologic screening or vaccination.

Effect of selective vaccination on rubella susceptibility and infection in pregnancy.

Abstract: The effect of school and adult vaccination on susceptibility to rubella in women of childbearing age was assessed in the Manchester area, where the population attending antenatal clinics is over 40 000 a year. Between 1979 and 1984 the proportion susceptible fell from 6.4% to 2.7%. In 1984, 4.2% of nulliparous women were susceptible compared with 1.4% of women in their second or subsequent pregnancy. Eighty five per cent of pregnant women screened and found to be non-immune were vaccinated post partum before leaving hospital. Requests for prevaccination screening of non-pregnant women increased in response to a national campaign and at the time of local outbreaks of rubella but only two thirds of those found to be nonimmune were subsequently vaccinated. During 1983 and 1984 infection was confirmed in 57 pregnant women--2% of those non-immune. Selective vaccination has reduced susceptibility to rubella in the childbearing population, but it is suggested that mass vaccination of children of both sexes should be added to the existing policy to control circulation of wild rubella virus and reduce the risk of infection to pregnant women who remain susceptible.

Detection of renal artery stenosis: experimental and clinical analysis of velocity waveforms.

Abstract: Mass screening of hypertensive patients by a noninvasive method could uncover the 10% of those cases where renal artery stenosis is the primary etiology. Treatment by transluminal angioplasty or surgery could replace a long-term medical regimen. To investigate an ultrasonic technique, normal velocity waveforms were obtained from the abdominal aorta, celiac artery and renal arteries in seven mongrel dogs using a 5 MHz, continuous-wave Doppler detector. Renal artery pressure gradients, volume flow rates and velocity recordings were subsequently made during induced proximal renal artery stenoses. The ratio of peak renal artery frequency to peak aortic frequency was 88% sensitive to stenoses of >20 mm Hg pressure gradient, while the renal artery systolic frequency window was 79% sensitive to the same obstructions. Ninety-five hypertensive and vascular surgical patients were examined using a 3 MHz duplex scanner with 175 of the 190 (92%) renal arteries adequately detected (clear signal with high diastolic component). Analysis of velocity waveforms based on peak frequency, proximal to distal peak frequency changes, evidence of flow disturbances and associated bruit were compared to contrast arteriograms in 84 vessels. Of the 76 (90%) arteries adequately examined by duplex scanning, 59 of 61 (97%) with 0–59% diameter reduction, 10 of 12 (83%) with 60–99% diameter reduction and 1 of 3 (33%) occlusions were correctly identified. Velocity waveform analysis can accurately detect renal artery stenosis and may prove effective in mass screening of hypertensive patients for renovascular disease.

Enzyme immunoassay for surveillance of Q fever.

Abstract: An enzyme-linked immunosorbent assay (ELISA) was developed to monitor antibodies against Coxiella burnetii among animal populations used in research and teaching facilities. Various antigenic components of C burnetii prepared from phase I and phase II whole cells and commercially available antigens were evaluated. A trichloroacetic acid extract was selected for routine use. There was a linear relationship between the transformed absorbance readings of the ELISA results and microagglutination (MA) titers. Comparison between positive or negative results of the MA test and ELISA gave 98.6% concordance. Using the MA test as the standard, ELISA results were 97.8% sensitive and 100% specific. The efficacy of ELISA was evaluated by testing ruminants with known histories of C burnetii infection. Antibody prevalence was 0 in 117 sheep with no history of C burnetii infection, 22% in 145 naturally infected sheep used for research, and 53% in 115 sheep used for vaccine field trials. Forty-eight percent of 120 dairy cows and 52% of 79 goats from endemically infected herds were seropositive. These results indicate that ELISA should be the test of choice for mass screening and surveillance of animals when Q fever is a suspected biohazard.

Indirect screening for Schistosoma haematobium infection: a comparative study in Ghana and Zambia.

Abstract: Four indirect approaches, based on inquiry into a past history of haematuria, visual inspection for blood in the urine specimens, and the use of reagent strips to detect haematuria and proteinuria, were evaluated to identify persons with Schistosoma haematobium infection. These approaches were applied individually and in three different screening sequences on two populations in Ghana and Zambia in order to identify infected children and adults for subsequent treatment in both areas. Detection of haematuria using reagent strips was the single approach with the highest sensitivity and specificity. The observation of gross haematuria (bloody urine), followed by detection of blood by reagent strips, identified 87% of infected children in both areas. This screening sequence showed the highest combined sensitivity and specificity in the identification of infected children as well as adults for treatment in both areas. Differences in the results between the two countries are discussed. This study emphasizes the need for evaluation of indirect screening procedures for the diagnosis of S. haematobium infection in each endemic area so as to establish criteria for their interpretation, prior to large-scale field application.

Strategies for preventing and screening for coronary heart disease.

Abstract: Intervention in the whole population in order to reduce the risk of coronary heart disease through altering lifestyles and specific intervention in individuals with identified high risk are complementary and not opposing strategies. Yet they are valid alternatives in that they present society with different choices and uses of its limited resources. To community health educators-and evidently to epidemiologists-mass intervention is to be preferred. To many physicians and cardiologists, the high risk strategy is likely to be more attractive. In the best of all possible worlds we should be able to afford both policies if they truly benefit society. But, so far, the results of investment in mass intervention trials have not been impressive-with a very considerable outlay and little or no yield (see later). It is argued that such trials are unnecessary because the cost of changing lifestyle on a mass population basis is really negligible and it is not expensive to promote campaigns to tell people to stop smoking, change their diet, or take more exercise: such advice is bound to do more good than harm, it is said. Yet improved health is not the only need of the population. Simply to argue that cigarette smoking should be eliminated without taking into account the repercussions on economy and employment is a narrow medical view. Similarly, to recommend changes in farming policy and farming economy leading to reductions in dairy farming by a quarter or a third needs much more consideration than it usually gets from the health education enthusiasts. Reduction in milk production and the requirement for less carcass fat imply a substantial reduction in animal food, of which barley is the major component. I Land will be released for other purposes but perhaps more than is needed for fruit and vegetables. The case for making large changes in agricultural strategy, with all its

Cigarette smoking and breast cancer: a case-control study of screening program participants

Abstract: A case-control study of Canadian women aged 40-59 years (n = 123; 369) has been conducted on the relationship of cigarette-smoking and initial visit breast cancer detection within a multicenter screening program. Among premenopausal women, a relative risk of 2.1 (1.1, 4.0) was found for ever-smokers versus never-smokers. There was a dose-response gradient with relative risks of 1.0, 1.3, 2.5, and 3.5 among women with 0, 1-200, 201-500, and greater than 500 cigarette-years of exposure, respectively. No overall association was detected among postmenopausal women but a significant interaction with parity was present in this group. When menopausal status was ignored, there was a nonsignificantly elevated risk of 1.4 (0.9, 2.1) for ever- versus never-smokers but the dose-response was significant with relative risks of 1.0, 0.9, 1.7, and 2.0 in the above four exposure categories, respectively. These results persisted despite adjustment for several important variables. These data are consistent with an interaction of smoking and participation in the screening study or with a possible etiologic role for smoking. Even if smoking is not related to breast cancer etiologically, these data still suggest that smokers who visit screening centers have an elevated risk of breast cancer detection on initial visit, especially among premenopausal women. They do not support the hypothesis of a protective effect of smoking and underscore the need for further study into this important relationship.

Development and progression of diabetic eye disease in Newcastle (1977-1984): rates and risk factors.

Abstract: A prevalence study of diabetic eye disease was conducted in Newcastle during 1977-1978. Ophthalmoscopic retinopathy was found in 49% of 1210 clinic diabetics, while vision-threatening retinopathy (VTR) (proliferative signs of maculopathy) occurred in 13%. Maculopathy was the commonest cause of visual loss, occurring frequently in subjects with non-insulin-dependent diabetes. This group has now been followed for up to seven years (including 70% at four years); incidence rates for the development of retinopathy and for progression to a vision-threatening stage can now be estimated. The study found that diabetics with no retinopathy developed this at a rate of 8% per year, while only 0.4% per year progressed to VTR. However, once any retinopathy was present, progression to VTR occurred in 6% per year (2% proliferative and 4% maculopathy); and if any retinal signs indicating the presence of capillary closure were noted the rate was 13% per year. These rates are for the group overall: however, certain parameters were found to influence the progression in individual patients. Included were the age at onset and the duration of diabetes, the presence of poor control (particularly in older diabetics on oral agents) or associated nephropathy. An analysis of these data and their implications for routine eye screening of diabetics is presented.