PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Screening”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Screening mammography: costs and use of screening-related services.

PURPOSE: To determine the costs and screening-related services in women undergoing screening mammography. MATERIALS AND METHODS: Study procedures were approved by the institutional committee for the protection of human subjects, and participants gave prior written consent. Data from a statewide mammography registry were used to identify imaging examinations, clinical consultations, interventional procedures, and pathology reports associated with screening mammography. The analysis included 99 064 women in the New Hampshire Mammography Network who underwent screening mammography between November 1, 1996, and March 31, 2000. Use of screening-related services in each case was tracked over an 18-month period, and procedure-specific national Medicare reimbursement rates from 2002 were applied for estimation of costs. Descriptive statistics (means, medians, standard deviations, 95% confidence intervals, frequencies, and percentages of resources and of costs) were calculated. RESULTS: The majority of subjects (85 809, or 87%) underwent screening mammography only. Of the 13 255 (13%) who underwent diagnostic imaging, additional mammographic views were obtained in most at the time of screening, within days or weeks of screening, or at short-interval follow-up. The total cost was $12 287 739. Approximately 80% ($9 777 670) of the total cost was related to imaging, and 68% ($8 410 313), specifically to screening mammography. Twenty percent ($2 510 069) of the total cost was associated with consultation and interventional procedures in only 2942 (3%) of the women, primarily those who underwent biopsy. Procedures resulted in benign findings in 2247 (76%) of the 2942. Mean total direct medical costs per capita were low ($99) in women who underwent screening mammography only, moderate ($286) in women who also underwent diagnostic imaging, and substantially greater in women who underwent biopsy ($993). CONCLUSION: While the largest component cost of screening mammography is that incurred in obtaining screening views alone, the highest costs per capita are associated with interventional procedures.

Adult↗

A simulation model for colorectal cancer screening: potential of stool tests with various performance characteristics compared with screening colonoscopy.

OBJECTIVE: Many new stool tests intended to detect neoplastic cells or cell products are developed at present for colorectal cancer (CRC) screening. The aim of this study was to simulate a population-based screening setting to assess and compare the potential for early detection and prevention of CRC of screening based on stool tests with different sensitivity and specificity and of screening with colonoscopy as a primary screening tool. METHOD: A Markov model was developed aimed to estimate the proportion of CRC cases which are early detected or prevented due to screening as well as the number of equired stool tests and colonoscopies per early detected or prevented CRC case. Model outcomes were calculated for the offer of annual stool testing from age 55 to 74 in combination with colonoscopic follow-up of positive test results and for the offer of screening colonoscopy as a primary screening tool at ages 55 and 65. The long-lasting risk reduction of colonoscopy allowing the removal of precancerous lesions was taken into account quantitatively. RESULTS: For a variety of stool tests with different performance characteristics, the proportion of CRC cases early detected or prevented was estimated to be higher for stool testing in combination with colonoscopic follow-up of positive test results compared with screening colonoscopy assuming levels of compliance to be expected for the respective screening scheme. Optimizing performance characteristics of stool tests in terms of detecting precancerous lesions, in addition to those in terms of detecting CRC, seemed to be crucial for maximizing effectiveness of CRC screening with stool tests. CONCLUSION: Screening based on new stool tests with colonoscopic follow-up of positive test results might offer a high potential for early detection or prevention of CRC.

Aged↗

Estimating mean sojourn time and screening test sensitivity in breast cancer mammography screening: new results.

OBJECTIVE: To assess if new screening techniques, increased use of hormone replacement therapy, or the transition from breast cancer screening trials to large scale screening programmes may influence the average time in preclinical screening detectable phase (mean sojourn time [MST]) or screening test sensitivity (STS). SETTING: Screening and interval data for 395,188 women participating in the Norwegian Breast Cancer Screening Programme (NBCSP). METHODS: Weighted non-linear least-square regression estimates using a tree step Markov chain model, and a sensitivity analysis of the possible impact by opportunistic screening between ordinary breast cancer screening rounds. RESULTS: MST was estimated to 6.1 (95% confidence interval [CI] 5.1-7.0) years for women aged 50-59 years, and 7.9 (95% CI 6.0-7.9) years for those aged 60-69 years. Correspondingly, STS was estimated to 58% (95% CI 52-64 %) and 73 % (67-78 %), respectively. Simulations revealed that opportunistic screening may give a moderate estimation bias towards higher MST and lower STS. Assuming a probable 21% higher background incidence, due to increased hormone replacement therapy use, MST estimates decreased to 3.9 and 5.0 years for the two age groups, and STS increased to 75 and 85%. CONCLUSIONS: The new estimates indicate that screening detectable phase is longer than that found in previous mammography trials/programmes, but also that the sensitivity of the screening test is lower. Overall, the NBCSP detects more cancer cases than most previous trials/programmes.

Aged↗

[Evaluation of population-based lung cancer screening in Niigata and analysis of interval cases based on comparison lung cancer registry with screening records].

Survival analysis has been used as one way to examine the efficacy of cancer screening. However, this type of study is susceptible to many sources of bias, especially to a length bias. In the city of Sukumo in Japan, a survival analysis considering screening history for the purpose of eliminating the length bias was conducted. The efficacy of lung cancer screening was assessed by comparing those who participated in the screening in the year preceding diagnosis, with those who did not. The 5-year survival rate was 44% in the former and 16% in the latter. We tried to evaluate population-based lung-cancer screening in Niigata using the method as that of Sukumo by comparing lung-cancer registry data with screening records, those who died of lung cancer from 1991 to 1994 in the study area and had the opportunity to be screened were categorized according to the screening history for the year preceding diagnosis. The 5-year survival rate was 41% in those who were screened and 19% in those not screened. In addition, the median survival time of the former was 37 months, significantly longer than the 12 months of the latter. Replication of study results in different populations may suggest the efficacy of lung-cancer screening on an annual basis. We also analyzed the clinical background of 47 interval cases in the search for a future direction for the improvement of the screening method.

Adult↗

Diagnostic yield in a biennial Hemoccult-II screening program compared to a once-only screening with flexible sigmoidoscopy and Hemoccult-II.

BACKGROUND: Flexible sigmoidoscopy (FS) has a higher degree of sensitivity for detecting colorectal neoplasia in the left side of the colon than Hemoccult (H-II). However, no randomized controlled trial has compared a single FS screening with a H-II screening program (annual or biennial) despite the well-documented mortality reduction from colorectal cancer (CRC) in the latter. The aim was to compare the diagnostic yield of colorectal neoplasia in two aged-matched groups from two different randomized screening trials; one group screened by a single FS+H-II, the other with biennial H-II over the course of 16 years. METHODS: 24,465 persons invited to participate in the Funen biennial H-II screening program were compared with 4,460 similar persons invited to another Funen trial using a single FS+H-II. RESULTS: Compliance in the biennial H-II program was 65.5% during the first screening round compared to 39.8% for FS+H-II. The cumulative number of persons with positive tests was 8.2% (positive H-II) in the biennial H-II program during 16 years and 20.3% (polyps > 3 mm in diameter seen at FS or positive H-II) for once-only FS+H-II. The diagnostic yield of CRC per 1,000 screened was 9.9 in the biennial H-II program and 6.6 after FS+H-II (6.5 and 2.7 per 1,000 invited). The yield of advanced adenomas (> or = 10 mm and/or villous structure and/or severe dysplasia) was 2.3% in the H-II program and 3.3% after FS+H-II among the screened persons, but this difference disappeared when persons invited, but not necessarily screened, were compared (1.5% versus 1.3%). CONCLUSION: Screening with H-II in a biennial screening program during 16 years detected more CRCs than a single screening with FS+H-II and a similar number of advanced adenomas.

Adenoma↗

[No major difference between population screening for cervical carcinoma at the present screening interval of 5 years and the former interval of 3 years].

OBJECTIVE: To assess the effect of extending the screening interval from 3 to 5 years on the detection of premalignant changes and invasive cervical carcinoma in the restructured population screening programme. DESIGN: Retrospective follow-up study. METHOD: The results were collected of the 1st round (1996-2000; 277, 377 women) and a part of the 2nd round (2001; 49,622 women; screening interval: 5 years) of the screening programme in Region West, the Netherlands. Histoscores for cervical intraepithelial neoplasia (CIN) 3 and squamous cell carcinoma (n/100 women investigated) and the hit count (sum of the histoscores for CIN 3, adenocarcinoma in situ and (micro)invasive cervical carcinoma) were calculated. Data of women with adenocarcinoma in situ and endocervical (adeno)carcinoma were recorded separately. The results of the 1st and 2nd round of the current screening programme (commenced in 1996) were compared with those of the historical screening programme that commenced in 1976 (screening interval: 3 years). RESULTS: From the 1st to the 2nd round of the historical screening programme that commenced in 1976, the histoscores for CIN 3 (3.33, 1.88) and squamous cell carcinoma (0.53, 0.19) and the hit count (3.92, 2.15) all diminished significantly. The current restructured programme, which commenced in 1996, showed low starting values for all three parameters, comparable to those in the 2nd round of the 1976 programme; a further reduction (0.16, 0.08; p < 0.01) was seen only in the histoscore for squamous cell carcinoma. In both rounds of both programmes, the histoscores for adenocarcinoma in situ (0.02, 0.02, 0.05, 0.04, respectively) and endocervical adenocarcinoma (0.04, 0.06, 0.05, 0.04) remained stable. CONCLUSION: In the current cervical carcinoma screening programme, with a screening interval of 5 years, the hit count of serious abnormalities remained constant while the incidence of squamous cell carcinoma decreased; this is in contrast to the historical screening programme (commenced in 1976), when both the hit count and the histoscore for CIN 3 diminished significantly. There were indications that cervical screening has no beneficial effect on the prevention of cervical adenocarcinoma.

Carcinoma↗

[Epidemiological evaluation of the protective effect for dying of stomach cancer by screening programme for stomach cancer with applying a method of case-control study--a study of a efficient screening programme for stomach cancer].

An epidemiological evaluation of the protective effect for dying of stomach cancer by screening programme for stomach cancer was conducted with applying a method of case-control study. And also in order to carry out an efficient screening programme, the age groups who should be intensively recommended to receive screening and an optimal screening time interval since the last test were analyzed. 527 cases of men and 273 of women, dying of stomach cancer in the years 1981-1989 in the Awa region of Chiba prefecture, were identified from Chiba Cancer Registry. For each case, 3 controls were drawn at random from Awa living residents (about 162000 inhabitants at 1989 national census), with being matched strictly according to the district of residence, sex and born within 3 years of birth-year. For both cases and controls, the information about the screening history until the date of diagnosis of the case in each matched set was collected respectively from comparison with the screening certification. The results showed a relative risk of 0.417 (99% CI 0.284-0.612) in ever screened men compared with never screened and 0.480 (99% CI 0.280-0.823) in women. The significant reduction in risk was intensively observed on age groups 40-74 years among men and 50-69 years among women and the protective effect continued at most in the following three years since last screening. For an efficiency of screening programme, these age groups should be intensively recommended to receive screening and it is allowable that an optimal screening time interval since last negative test is at most 3 years for general attendance.

Adult↗

Mass screening for diabetic retinopathy--a report on diabetic retinal screening in primary care clinics in Singapore.

INTRODUCTION: Mass screening for diabetic retinopathy is expensive and inaccessible if done by institutional ophthalmalogists. Most diabetics are seen in primary care. Hence it is logical to provide mass screening in primary care clinics. In Singapore, government polyclinics are ideal centres of screening as they are well organised and accessible to the community. SCREENING METHOD: An effective mass screening strategy must provide wide coverage, be low cost and have the ability to assess diabetic eyes accurately and quickly. Non-mydriatic fundal photography was used as the screening method. Mass coverage was achieved by rotating two cameras around six government polyclinics. Cost was reduced by training existing staff and organising the programme to provide a high turnover of screenees. The photographs were read by ophthalmologists in a government-owned hospital. Patients that required referral were referred to specialist eye clinics. RESULTS: A total of 13,296 patients were screened or rescreened during a period of 2 years (25 months). 2,911 patients or 21.8% of the total screened were found to have diabetic retinopathy. About half of these (10.8%) had sight threatening retinopathy. The most common sight threatening retinopathy was maculopathy (8.0%). Twenty-two percent of cases screened were referred. These include referral for other ocular conditions detected during the screening. CONCLUSION: Non-mydriatic fundal photography has proven to be both accessible and effective in screening diabetic eyes in urban Singapore and can be recommended for mass screening of diabetic eyes in the community.

Adult↗

Vision screening, eye examination and risk assessment of display screen users in a large regional teaching hospital.

In January 1993 the Royal Group of Hospitals Trust, which employs approximately 5000 staff, implemented the Health and Safety (Display Screen Equipment) Northern Ireland Regulations (1992). During 1994 all regular display screen equipment users were offered a vision screening test. In total 571 employees were screened using computerized vision screening software (City Visual Systems Ltd). Risk assessments were completed for 293 display screen work-stations. One hundred and twelve full eye examinations, carried out by optometrists, were performed on those who failed vision screening and on those who specifically requested an optometric assessment. Results indicate that whereas the proportion of users experiencing visual and general symptoms differed markedly from department to department (28-82%), the median number of individuals failing the screening test was 25% (range 9-40%). Those involved in uninterrupted display screen equipment work for prolonged periods reported visual and general work-related symptoms twice as frequently as those who spent less time working with DSE. The outcome of full eye examinations confirmed that less than 5% of display screen users required spectacles solely for display screen use. Work-station analysis indicated that ergonomic problems were common. The authors conclude that the successful management of health risks from display screen equipment requires simultaneous attention to work-place design, working patterns and eye care.

Adolescent↗

Screening for Down syndrome using first-trimester combined screening followed by second-trimester ultrasound examination in an unselected population.

OBJECTIVE: Recent studies have reported the efficacy of first-trimester combined screening for Down syndrome based on maternal age, serum markers (human chorionic gonadotropin, pregnancy-associated plasma protein A), and ultrasound measurement of fetal nuchal translucency. However, those do not incorporate the value of the widely accepted routine 20-22 weeks' anomaly scan. STUDY DESIGN: We carried out a multicenter, interventional study in the unselected population of a single health authority in order to assess the performance of first-trimester combined screening, followed by routine second trimester ultrasound examination and/or screening by maternal serum markers (free beta-hCG and alpha-fetoprotein measurement or total hCG, alpha-fetoprotein, and unconjugated estriol measurement) when incidentally performed. Detection and screen positive rates were estimated using a correction method for nonverified issues. A cost analysis was also performed. RESULTS: During the study period, 14,934 women were included. Fifty-one cases of Down syndrome were observed, giving a prevalence of 3.4 per 1000 pregnancies. Of these, 46 were diagnosed through first (n = 41) or second (n = 5) trimester screening. Among the 5 screen-negative Down syndrome cases, all were diagnosed postnatally after an uneventful pregnancy. Detection and screen positive rates of first-trimester combined screening were 79.6% and 2.7%, respectively. These features reached 89.7%, and 4.2%, respectively, when combined with second-trimester ultrasound screening. The average cost of the full screening procedure was 108 euros (120 dollars) per woman and the cost per diagnosed Down syndrome pregnancy was 7,118 euros (7909 dollars). CONCLUSION: Our findings suggest that 1 pragmatic interventional 2-step approach using first-trimester combined screening followed by second-trimester detailed ultrasound examination is a suitable and acceptable option for Down syndrome screening in pregnancy.

Adult↗

Are there differences between older persons who screen positive on the CAGE questionnaire and the Short Michigan Alcoholism Screening Test-Geriatric Version?

OBJECTIVES: To determine (1) the extent of agreement between the CAGE (acronym for cut down, annoyed by criticism, guilty about drinking, eye-opener drinks) and the Short Michigan Alcoholism Screening Test-Geriatric Version (SMAST-G) in identifying older persons who may have possible alcohol use disorders (AUDs) and (2) whether persons identified as having possible AUDs by each of these screening measures differ in their drinking, demographic, or health-related characteristics. DESIGN: Secondary analysis of a cross-sectional study using data from a self-administered mailed survey sample. SETTING: Three organizations were surveyed: (1) members of the American Association of Retired Persons and, in southern California, (2) managed care enrollees in a large medical group and (3) attendees of a community-based senior health center. PARTICIPANTS: One thousand eight hundred eighty-nine persons aged 55 and older completing a health risk appraisal for older persons (Health Risk Appraisal for the Elderly (HRA-E)). MEASUREMENTS: The HRA-E included items on drinking behaviors (including amount of alcohol use, the CAGE, and the SMAST-G) and health and demographic characteristics. RESULTS: Twenty-six percent of all persons screened positive on the CAGE or the SMAST-G. Fewer than half of all persons screening positive on either the CAGE or the SMAST-G, screened positive on both measures. Among current drinkers, persons screening positive on the SMAST-G alone drank less than persons screening positive on the CAGE alone, and these persons drank less than those screening positive on both the SMAST-G and the CAGE. More men screened positive on the CAGE alone than on the SMAST-G alone. CONCLUSION: Fewer than half of persons screening positive on either the CAGE or the SMAST-G screened positive on both measures, suggesting that these instruments may be capturing different aspects of unsafe drinking. A screening strategy employing both brief measures may identify more AUDs among older persons having differing demographic and health characteristics.

Age Factors↗

Comparing disease screening tests when true disease status is ascertained only for screen positives.

Disease screening is a fundamental part of health care. To evaluate the accuracy of a new screening modality, ideally the results of the screening test are compared with those of a definitive diagnostic test in a set of study subjects. However, definitive diagnostic tests are often invasive and cannot be applied to subjects whose screening tests are negative for disease. For example, in cancer screening, the assessment of true disease status requires a biopsy sample, which for ethical reasons can only be obtained if a subject's screening test indicates presence of cancer. Although the absolute accuracy of screening tests cannot be evaluated in such circumstances, it is possible to compare the accuracies of screening tests. Specifically, using relative true positive rate (the ratio of the true positive rate of one test to another) and relative false positive rate (the ratio of the false positive rates of two tests) as measures of relative accuracy, we show that inference about relative accuracy can be made from such studies. Analogies with case-control studies can be drawn where inference about absolute risk cannot be made, but inference about relative risk can. In this paper, we develop a marginal regression analysis framework for making inference about relative accuracy when only screen positives are followed for true disease. In this context factors influencing the relative accuracies of tests can be evaluated. It is important to determine such factors in order to understand circumstances in which one test is preferable to another. The methods are applied to two cancer screening studies, one concerning the effect of race on screening for prostate cancer and the other concerning the effect of tumour grade on the detection of cervical cancer with cytology versus cervicography screening.

Journal Article↗

An attempt to increase the efficiency of protein crystal screening: a simplified screen and experiments.

Macromolecular crystallization remains a bottleneck in structure determination by X-ray diffraction. Based on the data reflecting success rates of crystallization conditions in different screens and the information derived from the BMCD and other related studies, a simplified screen has been designed to increase the success rate of traditional screening and to save samples, time and cost. The screen has been tested with six protein samples which had been crystallized before and its comparison with Crystal Screen (Hampton Research) was also performed with lysozyme crystallization. The experimental results show that for obtaining crystal leads, the success rate of the simplified screen is reasonably higher. In addition, it has been successful in crystallizing two new proteins from snake venom using the simplified screen that had failed with Crystal Screen. These results indicate that the simplified screen, which assembles and optimizes the efficient crystallization conditions from distinct screens, extends the region of crystallization and improves the success rate of screening. Based on information of newly published efficient crystallization conditions, the simplified screen could be developed and optimized continuously in the future.

Animals↗

Second trimester maternal serum screening using alpha fetoprotein, free beta human chorionic gonadotropin and maternal age specific risk: result of chromosomal abnormalities detected in screen positive for Down syndrome in an Asian population.

BACKGROUND: This study was to determine the incidence of chromosome abnormalities in Taiwanese women undergoing prenatal chromosome analysis after a second trimester Down syndrome screening by using maternal age and serum dual-marker testing (alpha-fetoprotein and free-beta unit human chorionic gonadotropin). METHODS: A total of 10,098 Taiwanese women with pregnancy between 15 and 23 weeks' gestation received second-trimester Down syndrome risk evaluation by dual-marker and maternal age specific risk testing in a single medical center. The study took 22 months. Ninety-seven percent of this study population was less than 34 years old. Ninety-six percent of our cases were screened between 15-20 weeks of gestation. This population was included only after a routine ultrasonography scan for correction of gestational age and exclusion of major structural anomalies. By using an algorithm to detect Down's syndrome, with a risk of 1:270 as a cut-off value, 816 patients were screen-positive for Down syndrome (screen-positive rate 8.0%). Karyotypes were reviewed for 670 (82.1%) mothers who received prenatal karyotype analysis. RESULTS: Twelve cases of Down syndrome were identified in the screen positive group with an estimated detection rate of 67% (false positive rate 8%). Three cases of Down syndrome were detected in late trimester among the screen-negative group. Seven other fetal chromosome abnormalities were also found among the screen-positive pregnancy. In addition, seven cases were screen-positive for trisomy 18; all of these patients received amniocentesis and only one case was confirmed. CONCLUSION: These findings indicate that this screening program combining alpha-fetoprotein (AFP), free beta human chorionic gonadotropin (free-hCG) and maternal age-specific would achieve a screening efficiency in Taiwanese populations as comparable to those obtained in Caucasian populations. Our results also suggest that approximately 3% of pregnancies with a positive dual marker and maternal age-specific screen results will have a chromosome abnormality despite having a normal routine ultrasound scan. Mothers with positive screening results should be made aware of the implications of a positive result.

Adult↗

Healthcare and patient costs of a proactive chlamydia screening programme: the Chlamydia Screening Studies project.

BACKGROUND AND OBJECTIVE: Most economic evaluations of chlamydia screening do not include costs incurred by patients. The objective of this study was to estimate both the health service and private costs of patients who participated in proactive chlamydia screening, using mailed home-collected specimens as part of the Chlamydia Screening Studies project. METHODS: Data were collected on the administrative costs of the screening study, laboratory time and motion studies and patient-cost questionnaire surveys were conducted. The cost for each screening invitation and for each accepted offer was estimated. One-way sensitivity analysis was conducted to explore the effects of variations in patient costs and the number of patients accepting the screening offer. RESULTS: The time and costs of processing urine specimens and vulvo-vaginal swabs from women using two nucleic acid amplification tests were similar. The total cost per screening invitation was 20.37 pounds (95% CI 18.94 pounds to 24.83). This included the National Health Service cost per individual screening invitation 13.55 pounds (95% CI 13.15 pounds to 14.33) and average patient costs of 6.82 pounds (95% CI 5.48 pounds to 10.22). Administrative costs accounted for 50% of the overall cost. CONCLUSIONS: The cost of proactive chlamydia screening is comparable to those of opportunistic screening. Results from this study, which is the first to collect private patient costs associated with a chlamydia screening programme, could be used to inform future policy recommendations and provide unique primary cost data for economic evaluations.

Adolescent↗

Practical community screening for diabetic retinopathy using the mobile retinal camera: report of a 12 centre study. British Diabetic Association Mobile Retinal Screening Group.

OBJECTIVE: To document the performance of 12 diabetes eye screening units in different health districts which were financed by a single charitable donation. DESIGN: Each location was equipped with a retinal camera and screening vehicle, and the lead clinician developed the screening service configuration to suit local conditions. SETTINGS: Districts were chosen on the basis of interest in developing effective diabetes eye screening services. Characteristics of districts varied from largely rural to exclusively urban. SUBJECTS: People with diabetes who attended either general practice or hospital diabetes services were screened. MAIN OUTCOME MEASURES: Referral for ophthalmological opinion and use of laser therapy for new vessel formation or exudative maculopathy. RESULTS: A total of 64,905 screening episodes were recorded. Full data were available on 42,803 episodes which led to 2400 referrals (5.6%) and 516 of which resulted in laser therapy (1.2% of those screened or 21.5% of those referred). Where sequential data were available a year by year fall in sight threatening retinopathy incidence was demonstrated as the screening programmes detected incipient problems in the initial cycles of screening. The average cost of screening was Pounds13.11 per patient and the average cost of identifying a person requiring laser therapy was Pounds1110. Financial responsibility for running the service has been taken on by 10 of the 12 health districts. CONCLUSIONS: Diabetes eye screening using a mobile retinal camera is effective, efficient and robust. It is important that the service specification is designed to suit the geography and existing diabetes services in each district.

Costs and Cost Analysis↗

Use of hormone therapy and risk of breast cancer detected at screening and between mammographic screens.

Postmenopausal hormone therapy (HT) is associated with increased risk of breast cancer, but in women undergoing breast cancer screening it is not clear whether use of HT is associated with increased risk of breast cancer detected at screening or between screens (interval cancer). Further, it is unclear whether the use of the HTs that have been common in Scandinavia is associated with higher risk of breast cancer than the HTs used in other countries. Our study was based on data from 296,651 women aged 50-69 years, who participated in the Norwegian Breast Cancer Screening Program during 1995-2004. After a mean enrollment time of 3.8 years, 1,512 women were diagnosed with invasive screen detected breast cancer, and 814 with invasive interval breast cancer. Cox regression models were used to estimate hazard ratios (HRs) of breast cancer associated with HT use, after adjusting for confounders. Ever users of HT had a 58% increased risk of breast cancer, compared to never users. The HRs associated with HT use were 1.45 (95% confidence interval (CI) = 1.29-1.63) for screen detected and 1.89 (95% CI = 1.61-2.23) for interval cancer. The difference between screen detected and interval cancer was statistically significant (p = 0.011). The HR of breast cancer increased with duration of HT use, but significantly more so for interval than for screen detected cancer (use of HT for 5 or more years compared to never use; HR = 2.91, 95% CI = 2.10-4.04 and HR = 1.94, 95% CI = 1.51-2.50, respectively; p = 0.002). The population attributable fraction of breast cancer due to HT use was 19.8% overall. Ever users of HT tended to develop a cancer of lower grade. No other differences in histological tumor characteristics were observed between ever and never users of HT among screen detected or interval cancers. The estimated risks of either breast cancer overall with HT use are higher in Norway than reported in similar studies from the U.S. HT-use is a stronger risk factor for interval cancer than for screen detected cancer. The increased risk of interval cancer, which may partly be due to decreased sensitivity of mammograms in HT users, remains a challenge in breast cancer screening programs.

Aged↗

Effect of organized screening on the risk of cervical cancer. Evaluation of screening activity in Iceland, 1964-1991.

The Icelandic Cancer Society launched a screening programme for cervical cancer in June 1964. The aim was to lower the incidence and mortality rates by screening the age group 25-69 at 2- to 3-year intervals. This report analyses the trends in invasive and pre-invasive disease and the distribution of stage and histology, and also evaluates the attendance, the target age group and the screening interval. Before screening, the incidence and mortality rates were on the increase but both have since fallen significantly. Screening greatly affected the rate of microinvasive and stage > or = II squamous-cell carcinomas but not the rate of adeno- and adenosquamous carcinoma. The mean age at detection of invasive cancer has decreased significantly and cancer has become practically non-existent among correctly screened subjects over the age of 69. Among younger women the rates of moderate and severe pre-invasive lesions at first visit increased significantly after 1980. The rate of these lesions was fairly consistently high only 1 year after the first normal visit. It is concluded that organized screening, co-ordinated with spontaneous activity, is effective in reducing the risk of cervical cancer. Regular high attendance and strict follow-up of abnormal cases is a prerequisite for good screening results. Screening should preferably start at about the age of 20 and extend to 60-69 years of age, depending on the number of negative smears by that age. Screening can safely start with a screening interval of 2 to 3 years, but this interval can probably be extended to 4 or 5 years at older ages.

Adenocarcinoma↗