Using the Cancer Risk Management Model to evaluate the health and economic impacts of cytology compared with human papillomavirus DNA testing for primary cervical cancer screening in Canada.

BACKGROUND: In Canada, discussion about changing from cytology to human papillomavirus (hpv) dna testing for primary screening in cervical cancer is ongoing. However, the Canadian Task Force on Preventive Health Care has not yet made a recommendation, concluding that the evidence is insufficient. METHODS: We used the cervical cancer and hpv transmission models of the Cancer Risk Management Model to study the health and economic outcomes of primary cytology compared with hpv dna testing in 14 screening scenarios with varying screening modalities and intervals. Projected cervical cancer cases, deaths, colposcopies, screens, costs, and incremental cost-effectiveness were evaluated. We performed sensitivity analyses for hpv dna test costs. RESULTS: Compared with triennial cytology from age 25, 5-yearly hpv dna screening alone from age 30 resulted in equivalent incident cases and deaths, but 55% (82,000) fewer colposcopies and 43% (1,195,000) fewer screens. At hpv dna screening intervals of 3 years, whether alone or in an age-based sequence with cytology, screening costs are greater, but at intervals of more than 5 years, they are lower. Scenarios on the cost-effectiveness frontier were hpv dna testing alone every 10, 7.5, 5, or 3 years, and triennial cytology starting at age 21 or 25 when combined with hpv dna testing every 3 years. CONCLUSIONS: Changing from cytology to hpv dna testing as the primary screening test for cervical cancer would be an acceptable strategy in Canada with respect to incidence, mortality, screening and diagnostic test volumes.

Cost-effectiveness of breast cancer screening policies using simulation.

In this paper, we study breast cancer screening policies using computer simulation. We developed a multi-state Markov model for breast cancer progression, considering both the screening and treatment stages of breast cancer. The parameters of our model were estimated through data from the Canadian National Breast Cancer Screening Study as well as data in the relevant literature. Using computer simulation, we evaluated various screening policies to study the impact of mammography screening for age-based subpopulations in Canada. We also performed sensitivity analysis to examine the impact of certain parameters on number of deaths and total costs. The analysis comparing screening policies reveals that a policy in which women belonging to the 40-49 age group are not screened, whereas those belonging to the 50-59 and 60-69 age groups are screened once every 5 years, outperforms others with respect to cost per life saved. Our analysis also indicates that increasing the screening frequencies for the 50-59 and 60-69 age groups decrease mortality, and that the average number of deaths generally decreases with an increase in screening frequency. We found that screening annually for all age groups is associated with the highest costs per life saved. Our analysis thus reveals that cost per life saved increases with an increase in screening frequency.

Health-related quality of life and cost-effectiveness studies in the European randomised study of screening for prostate cancer and the US Prostate, Lung, Colon and Ovary trial.

Decisions on policies for screening for prostate cancer require that information upon health-related quality of life (HRQL) and cost-effectiveness (CE) be available, as the lead time for some of the cases detected by screening will be very long and detriments in quality of life could have a major impact on the subjects remaining life-span. A framework within which both HRQL and cost-effectiveness of prostate cancer screening can be assessed is presented. Studies of both are ongoing in the European Randomised Study of screening for prostate cancer and the US Prostate, Lung, Colon and Ovary trial. Preliminary information confirms that it is important to study screened subjects and controls, and not to assume that inferences derived from study of prostate cancer outside screening trials can be extrapolated to the trials. However, it will require prolonged study to enable the overall effects on quality of life, and on cost-effectiveness to be determined. Such studies are ongoing for the two trials.

Understanding dignity in the lives of homeless persons.

The current investigation is a planned, systematic study of dignity as critical to understanding the experience of homelessness and improving services and programs for the homeless. Specifically, we conducted a thematic content analysis of interviews with 24 homeless men and women to identify their perception of specific environmental events that validate and invalidate dignity. In addition, we explored the impact that these events have on homeless persons. Eight types of events were identified that sustain dignity such as being cared for by staff and having resources available to meet basic needs. Eight types of events were found that undermine dignity, such as being yelled at or insulted by staff persons and having staff use rules in an excessive and arbitrary way. Two outcomes followed the sustenance of dignity including increased self-worth and motivation to exit homelessness. Three outcomes followed the undermining of dignity including anger, depression, and feelings of worthlessness. The results suggest that dignity is an important variable to consider in understanding the experience of homelessness. Policies and programs that support validating the dignity of homeless persons are encouraged.

Adults with mental retardation as supports to their parents: effects on parental caregiving appraisal.

This study was conducted to determine whether support provided to caregivers by their adult children with mental retardation would influence caregiving appraisals. We also examined how severity of disability of the adult child, personal and social resources of the caregiver, and amount of caregiver assistance to the adult with mental retardation influenced caregiving appraisals. Using surveys and interviews we collected information from 80 primary caregivers on caregiving burden and satisfaction and six predictors of burden and satisfaction. Findings indicate that greater support from the adult child to the caregiver resulted in greater satisfaction and less burden. Adaptive and maladaptive behaviors and caregiving assistance all predicted caregiving satisfaction but only maladaptive behaviors predicted caregiving burden.

Workshop on screening for cancer of the uterine cervix in Central America.

PIP: This article describes the objectives and content of a workshop held in Managua, Nicaragua, during November 1995, on screening for cervical cancer. The aims were to discuss cost-effective models of screening in countries with a high incidence of cervical cancer and to reach a consensus on principles for screening that is balanced with a country's resources. The workshop aimed to develop a planning framework and to identify program strengths and weaknesses by country. In 1990 there were 25,000 deaths due to cervical cancer in Central America; even so, most countries attach a low priority to cervical cancer screening. Workshop plenary sessions were devoted to discussions about the natural history of cancer of the cervix and the implications for screening, the high costs of human papillomavirus (HPV) tests, approaches to national registries of cervical cancer, screening issues in Central America, downstaging, laboratory quality control issues, treatment of abnormalities, recruitment of women, and IEC. This report includes individual country program reports for Nicaragua, Panama, Haiti, the Dominican Republic, Guatemala, Honduras, and St. Vincent and the Grenadines. Participants concluded that priority should be placed on education about cancer and cancer of the cervix and education of primary health care professionals. It was agreed that all participating countries should begin pilot programs adapted to resource availability, with the idea of a later nationwide expansion. Health care professionals who treat women during the prime reproductive years should use the opportunity to identify women at high risk of invasive cancer. There is overcoverage of women aged under 35 years and insufficient coverage of women aged 35-64 years. Health programs need to enlist the help of women's groups in creating a need and demand in communities. Cytology laboratories need to provide quality services.^ieng

The costs and benefits of breast cancer screening.

The costs and benefits of breast cancer screening can be placed in the framework usually used for sensitivity and specificity. All those screened incur the costs associated with the test. In addition, only the segment of the true positives who, in the absence of screening, would die of their disease but with screening will survive to die of another cause truly benefit; all other true positives acquire lead time without benefit. In the Canadian National Breast Screening Study, simpler treatment of screen-detected cancer was not achieved. The true negatives benefited from reassurance, but the majority were not at risk of breast cancer anyway. The false negatives were disadvantaged from false reassurance, but in practice the percentage is low, and the consequences are not dire. There are major costs associated with the false positive state, including anxiety, unnecessary biopsies, and residual scarring; major endeavors are justified to reduce them and improve the specificity of screening. In practice, with no benefit demonstrated for women 40-49 years of age, the costs are too great to justify continuation of screening this age group merely in the hope that benefits will eventually be demonstrated. For women older than 50, the degree of benefit may have been overestimated, especially in an era when improvements in therapy affect screen-detected and nonscreen-detected cases alike. We may have overestimated the benefit-cost ratio of screening this age group also; thus, careful monitoring of the outcome of ongoing programs over the next few years is essential.

Canadian National Breast Screening Study: assessment of technical quality by external review.

Mammograms from the Canadian National Breast Screening Study (NBSS) were reviewed by three external experts to provide an objective evaluation of their technical quality, to establish a model for auditing mammograms in a screening program, and to assess whether NBSS mammograms improved over time. The sample reviewed included 10 randomly chosen mammograms from each of 15 screening centers for each calendar year of their operation between 1980 and 1987. All 830 mammograms were reviewed on two consecutive days in randomized sequence by each reader, and rated 0-3 for each of four criteria including positioning and image quality, with a total possible score of 0-12. Although the mammograms were not in temporal sequence when reviewed, the scores assigned by each reader were significantly higher for mammograms dating from later years. Subjects' ages at entry (40-49 vs 50-59 years) did not affect the score. The largest increase in scores was associated with a 1985 protocol change in which mediolateral oblique positioning replaced straight mediolateral positioning. This study reinforces the importance of monitoring technical quality in screening programs and establishes that the NBSS benefited from technical improvements during its operation. A retrospective review of NBSS mammography by three external reviewers confirmed that technical quality improved from 1980 to 1987. This improvement was associated with improved technology (film, processing, and units) and with the quality assurance programs operating during the NBSS, which identified problems and offered remedies.

Echocardiographic assessment of the left ventricle of endurance athletes just before and after exercise.

Fourteen normal subjects and 10 marathon runners were studied using postexercise echocardiography to assess left ventricular (LV) wall thickness, afterload and systolic performance. Cuff systolic blood pressures and M-mode echocardiographic recordings were obtained in the supine position before and within 2 minutes of termination of maximal treadmill exercise. Both groups had increased LV dimensional shortening (% fractional shortening) and stroke volume after exercise, although runners had larger increases compared to untrained normal subjects (p less than 0.05). Preload, as estimated by LV end-diastolic dimension, was greater in runners compared to normal subjects at rest (52 vs 48 mm, p less than 0.05). However, preload did not change after exercise in either group. Afterload, estimated by LV end-systolic wall stress, decreased after exercise in both groups; however, runners had lower afterload at rest and immediately after exercise compared to normal subjects (p less than 0.05). The runners' greater LV end-systolic wall thickness appears to account for their lower afterload. Data indicate that marathon runners have lower afterload at rest and greater decrease in afterload after maximal exercise, compared to untrained normal subjects.

Demand analysis of mental health service use among ethnic subpopulations.

This paper estimates demand for mental health services by blacks, Hispanics, and whites, as well as males and females, using a three-part regression model. It examines the probability of mental health use and the level of outpatient and inpatient use. The data base is the high option Blue Cross/Blue Shield Federal Employee Health Benefits Plan for the 1979 to 1981 period. All user subpopulations sharing this plan have the same coverage, so differences in demand and utilization are related to ethnic and racial background, age, salary, outpatient visit copayment and market area characteristics, including the supply of psychiatrists. Results show vast differences in demand for care by ethnic, racial, and gender groups with identical insurance coverage. Alternative explanations for the differences are suggested.

The ethics, the risks and the benefits of screening.

The ethical principles underlying screening are reviewed. It is concluded that the ethical requirements for the introduction of screening are stringent, and that screening should not be offered in the absence of unequivocal evidence of effectiveness except in a carefully conducted research study. Part of the reasons for this are the risks associated with screening, which extend beyond the risk of the test itself, to those associated with invitations for screening, false reassurance for false negatives, the diagnostic process and the problem of false positives, and the overtreatment of those with borderline abnormalities. Finally, the benefits expected from screening are considered, especially reduction in mortality from the disease, but also reduction in incidence if a precursor is detected by the test, less radical treatment for cases detected, reassurance for those who test true negative, and resource savings, though it has to be demonstrated that these exceed resource costs.

An exploratory case-control study of brain tumors in adults.

An exploratory study of brain tumors in adults was carried out using 215 cases diagnosed in Southern Ontario between 1979 and 1982, with an individually matched, hospital control series. Significantly elevated risks were observed for reported use of spring water, drinking of wine, and consumption of pickled fish, together with a significant protective effect for the regular consumption of any of several types of fruit. While these factors are consistent with a role for N-nitroso compounds in the etiology of these tumors, for several other factors related to this hypothesis, no association was observed. Occupation in the rubber industry was associated with a significant relative risk of 9.0, though no other occupational associations were seen. Two previously unreported associations were with smoking nonfilter cigarettes with a significant trend and with the use of hair dyes or sprays. The data do not support an association between physical head trauma requiring medical attention and risk of brain tumors and indicate that exposure to ionizing radiation and vinyl chloride monomer does not contribute any appreciable fraction of attributable risk in the population studied. The findings warrant further detailed investigation in future epidemiologic studies.