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Biomedical subjects

M C Costanza

Publications and source records attributed to M C Costanza.

At least 19 recordsLinked to original sources
PubMed1995

Matching.

Matching is an intuitively appealing design strategy for ensuring balance on one or more potential confounding variables, usually either among subjects who were exposed or unexposed to a suspected risk factor for disease in a cohort study or between diseased and nondiseased subjects in a case-control study. But does matching always automatically "control" confounding and is it always as good a strategy as it seems? It is the intention of this review to shed light on these questions primarily through illustrative examples of the effects of matching on the validity of point estimates of the odds ratio between exposure and disease status in both types of study designs. It is seen that the results of matching are more or less in line with expectations in cohort studies, but that matching can lead to unexpected results in case-control studies. In a case-control study, confounding is not automatically controlled by matching per se; rather, matching and a statistical analysis that properly accounts for the matching are needed to obtain a valid estimate of effect in a case-control study design.

Confounding Factors, Epidemiologic↗
PubMed1995

Breast-conserving surgery for breast cancer: patterns of care in a geographic region and estimation of potential applicability.

BACKGROUND: It has been postulated that one of the rewards of breast cancer screening is the increased likelihood of receiving breast-conserving surgery. The recent wide application of screening mammography has led to an acceleration in the otherwise gradual shift toward smaller, earlier-stage breast cancer that has been occurring since the turn of the century. METHODS: We examined data from patients with pathologically diagnosed breast cancers from all general hospitals in the state of Vermont for use of breast-conserving surgery by era (1975-1984 [n = 1,652] versus 1989-1990 [n = 683]), method of cancer detection, age, clinical tumor-node-metastases (cTNM) stage, pathologic size, and node status. RESULTS: Cancers detected by mammography were 2% in 1975-1984 and 36% in 1989-1990. Invasive breast cancers < 2 cm maximum pathologic diameter were 34% in 1975-1984 and 50% in 1989-1990 (p < 0.001). Statewide, the use of breast-conserving surgery for invasive cancer increased from 8.6% in 1975-1984 to 42.9% in 1989-1990 (p < 0.001). In 1989-1990 at the single university hospital, 73% of the patients were treated with breast-conserving surgery versus 22% at the community hospitals (range 0-39%, p < 0.001). Differential referral patterns related to stage and age did not appear to explain the variation, because the percentages of cTNM stage I and II patients at the university hospital were similar to those of the community hospitals. Using the university hospital as the standard, we estimated that at least 67% of all patients in the state were eligible for breast-conserving surgery in the years 1975-1984 and 73% in the years 1975-1984, a 6% increase. CONCLUSIONS: Most of the variation in breast-conserving surgery was related to factors other than patient age and stage of disease. Variation was probably related more to local community factors and physician attitudes. At least two-thirds of the women in the state were eligible for breast-conserving surgery even before the wide use of mammography screening.

Adult↗
PubMed1994

Development of a community breast screening promotion program using baseline data.

The process of developing a comprehensive community-based breast screening program for the Breast Screening Program Project is presented in this article. Behavior change theories were used to develop a program effects model which served as the conceptual foundation for a comprehensive breast screening program. This program would enlist professional and lay resources to promote breast screening through public and physician education and through improved access to mammography. Baseline survey data were used to focus program components on educational needs of women ages 40 and older for participating in regular mammography, clinical breast exam, and breast self-exam. The program effects model was also used as an evaluation framework to specify the intermediate changes that will be accomplished to reach a hypothesized 15% increase in screening participation between a study area receiving the program and two comparison areas. Results of this study will be of immediate value to other communities planning breast screening promotion programs.

Adult↗
PubMed1994

[Nutritional balance of the diet of the adult residents of Geneva].

Diet of the Swiss population has probably changed over the last 10 years, but these changes have not been recorded yet by nutritional studies. In the present study, 3 registered dieticians interviewed over the telephone 626 adults, resident of Canton Geneva, using a 24 hour recall. Interviews were performed during the 7 days of the week. Participants were randomly selected according to their age, sex and nationality. Participation was 80%. The following caloric (C) and nutritional intakes in proteins (P), lipids (L), carbohydrates (CH) and alcohol (A) were recorded: In non Swiss men: C = 2464 kcal/j., P = 16.2%, L = 32.4%, CH = 44.4%, A = 7.0%; in Swiss men: C = 2752 kcal/j., P = 15.3%, L = 34.0%, CH = 43.5%, A = 7.1%; in non Swiss women: C = 1897 kcal/j., P = 16.4%, L = 35.1%, CH = 46.5%, A = 2.4%; in Swiss women: C = 1865 kcal/j., P = 15.0%, L = 35.3%, CH = 46.0%, A = 3.2%. Total caloric intake and iron intake decreased with age. Older women ate less calcium than younger. In summary, the most important determinants of diet are age and sex. Proportion of lipids is relatively low in both men and women. Small differences related to nationality were observed in men.

Adult↗
PubMed1994

Comparability of telephone and household breast cancer screening surveys with differing response rates.

We compared telephone and household surveys as methods for obtaining information about breast cancer screening. The study population was comprised of women age 40 years or older who were permanent residents of two large areas of Florida. We contacted women using random digit dialing for the telephone survey. We used a stratified multistage design for the household survey. Response rates were 49% (telephone) and 77% (household). Distributions of most screening (mammography, clinical examination, and breast self-examination) and demographic variables were comparable for the two surveys; income was higher in the telephone survey. Both surveys underestimated the proportion of older women, based on 1990 Census data.

Adult↗
PubMed1993

Breast cancer and earlier detection efforts. Realized and unrealized impact on stage.

OBJECTIVE: To test our hypotheses that increased public and professional education in breast cancer detection (screening mammography, clinical breast examination, and breast self-examination) would lead to detection at earlier stages of disease with each of the three methods. DESIGN AND SETTING: A survey study of all pathologically diagnosed breast cancers in a defined geographic area (all nonfederal general hospitals in the state of Vermont) before (1975-1984, n = 1652) and after (1989-1990, n = 683) screening mammography became more commonly used. MAIN OUTCOME MEASURES: Method of detection of breast cancer and stage at detection. RESULTS: The age-adjusted annual incidence rate of breast cancer among adult women was 99 per 100,000 during the years 1975 to 1984 compared with 169 per 100,000 during 1989-1990 (P < .001). Mammography as the method of detection increased in use from 2% to 36% (P < .001). In the later era, invasive breast cancers were detected at more favorable TNM stage (P < .001); mean maximum tumor diameter was smaller (2.2 cm vs 2.7 cm; P < .001); percentage of histologically positive nodes was lower (37% vs 47%; P < .001). When mammographically detected cancers were excluded from the analysis of invasive cancers, the mean maximum tumor diameter and percentage of negative nodes in the two eras were similar even though there was an apparent shift to detection at an earlier clinical stage. CONCLUSION: The earlier stages of detection and the sudden increase in incidence could almost entirely be credited to screening mammography. Mammographic screening had a much greater impact on stage at detection in women aged 50 years and older than in those younger than 50 years.

Adult↗
PubMed1992

Clinical breast examination and breast self-examination. Past and present effect on breast cancer survival.

Increasing attention to self-detection of breast masses and clinical breast examination during this century have contributed to a progressive reduction in the size of breast cancers at detection and a progressive improvement in survival. Mammography is more sensitive than breast palpation for the detection of breast cancer, however, mammography does not detect all palpable cancers and additional interval cancers become palpable between screenings. Breast self-examination, clinical breast examination, and mammography are complementary screening modalities. In populations where mammography is not available or is not appropriate as a screening modality, clinical breast examination and breast self-examination are particularly important.

Breast Neoplasms↗
PubMed1992

Prevention of cigarette smoking through mass media intervention and school programs.

OBJECTIVES: In this study we tested the ability of mass media interventions to enhance the efficacy of school cigarette smoking prevention programs. METHODS: For 4 years, students in one pair of communities received media interventions and school programs that had common educational objectives. Students in a matched pair of communities received only the school programs. The combined cohort of 5458 students was surveyed at baseline in grades 4, 5, and 6 and was followed up annually for 4 years. RESULTS: Significant reductions in reported smoking, along with consistent effects on targeted mediating variables, were observed for the media-and-school group. For cigarettes per week the reduction was 41% (2.6 vs 4.4); for smoking cigarettes yesterday the reduction was 34% (8.6% vs 13.1%); and for smoking in the past week the reduction was 35% (12.8% vs 19.8%). No effects were observed for substance use behaviors not targeted by the interventions. CONCLUSIONS: These results provide evidence that mass media interventions are effective in preventing cigarette smoking when they are carefully targeted at high-risk youths and share educational objectives with school programs.

Adolescent↗
PubMed1992

The modeling of breast cancer deaths in Vermont.

Methodologic issues in modeling breast cancer deaths were investigated through modeling the number of breast cancer deaths in Vermont for the period 1975 to 1988. Age-specific incidence rates, case fatality rates, and secular trends of these rates were necessary to represent the observed trend in breast cancer deaths over this time period. Additional information, such as mortality from other causes, stage distribution, or screening history, was not necessary. Incidence and survival information were obtained from a statewide population-based breast cancer registry in Vermont and the Surveillance, Epidemiology and End Results (SEER) program. SEER incidence rates overestimated the actual number of deaths for long-term survival rates. Case fatality rates and secular trends in incidence and survival reported by SEER were appropriate. These results can be applied to the planning of community intervention studies by providing the essential expected numbers of deaths in control communities.

Adult↗
PubMed1991

Estimation of the design effect in community intervention studies.

This paper considers the estimation of the variance of a mortality rate in community intervention studies with little or no replication of intervention regimens. Our approach in estimation of this cluster sampling variance is to determine the variance for simple random sampling and multiply it by a design effect which we calculate with use of information obtained from other sources. When the county is the unit of randomization and the outcome is mortality, we calculate the design effect as the ratio of the age adjusted mortality rates for single stage cluster sampling relative to simple random sampling; we use information from all counties in a state in the calculations. We apply this approach empirically for breast cancer mortality. We found that these design effects were dependent on length of time for accumulation of deaths (1.1 for one year up to 3.5 for eight years) and were quite consistent for the three states and nine years considered in the investigation. We present a model that accounts for the time dependence of the design effect and we show it provides a good representation of the observed relationship.

Adult↗
PubMed1990

A community-wide program in breast self-examination training and maintenance.

This study reports on the effects of innovative community-wide breast self-examination education approaches in increasing breast self-examination frequency and quality, and ability to detect breast lumps during a 1-year training program and a second-year maintenance program. Four Vermont communities were randomly assigned to receive breast self-examination training plus maintenance, training alone, control (with full measurement), and low-measurement control. Random digit dialing telephone surveys were conducted at baseline and at 1- and 2-year follow-up with a panel of 637 women representing all adult women in the first three communities. The low-measurement control community received only baseline and second-year follow-up surveys with a panel of 238 women. Home interviews to determine breast self-examination palpation skills and lump detection on silicone breast models were conducted in first- and second-year follow-up surveys. Results of the first-year follow-up survey indicated significant increases in breast self-examination frequency, quality, and number of lumps detected for women in communities receiving the training program compared with controls; in the second year, women in the community also receiving breast self-examination maintenance showed greater improvement in reported breast self-examination quality and detected more breast lumps than did women in other communities.

Adult↗
PubMed1988

Development of a smoking prevention mass media program using diagnostic and formative research.

The process of developing a mass media campaign to prevent smoking among adolescents is described in detail. This campaign supplements a school smoking prevention program and shares educational objectives with the school program but is otherwise independent. It comprises various television and radio 30- and 60-sec "spot" messages. The campaign development process includes identifying educational objectives and strategies for appealing to young people; conducting diagnostic surveys and focus groups to determine target audience interests and perceptions about smoking and media content; suggesting approaches to producers to create preliminary television and radio messages for testing; conducting formative pretests with target groups to select optimal messages and suggest improvements to those messages; producing final messages for media presentation; and developing a media exposure plan to place messages in local media at optimal times for reception by target audiences. The media campaign is being evaluated in a 5-year project with 5,500 adolescents in four communities to determine the additional effect of mass media over a school program alone in preventing smoking.

Adolescent↗
PubMed1987

Breast self-examination practices and attitudes of women with and without a history of breast cancer.

Breast self-examination (BSE) practices and attitudes of three groups of women were compared using a mailed survey. Subjects were 59 women with previous breast cancer, 33 women with previously treated benign breast lump(s), and 80 general-population women with no history of breast disease. Groups were compared on frequency, proficiency, and knowledge of BSE. Determinants of practice were examined using attitudinal variables from the Health Belief Model. Results indicated that the breast cancer group had significantly higher rates of BSE frequency, proficiency, and knowledge than did the general-population group. The breast cancer group perceived cancer to be significantly less threatening than did the other two groups, although the general-population group reported significantly less susceptibility to breast cancer. Within-group analyses revealed that barriers to BSE practice accounted for the greatest amount of variance in BSE frequency in all three groups. These results are discussed.

Attitude to Health↗
PubMed1986

Using medical records for older patient education in ambulatory practice.

The effectiveness of sharing medical records in improving physician-older patient communication was evaluated in 203 ambulatory chronically ill older patients (mean age, 70.1 years) by a randomized controlled trial. Ninety-five experimental group patients received copies of their physicians' progress notes 1 week after their last office visit, and 108 control patients did not. After 1-2 weeks, knowledge of health problems, medication, and nonmedication treatments was assessed by interview. Experimental group patients knew 74.1% of their health problems, compared with 64.1% in the control groups (P less than 0.05). There was no difference in knowledge of medications or adherence to medication regimens. Experimental group patients displayed higher treatment knowledge scores than control group patients (P less than 0.01). Less-educated patients showed greater adherence to nonmedication treatments. Shared medical records can enhance physician-older patient communication about health problems and nonmedication treatments, but they do little to enhance medication knowledge or adherence to medication regimens.

Aged↗
PubMed1985

Adverse relationship between blood transfusions and survival after colectomy for colon cancer.

Random-donor blood transfusions are deliberately given before cadaver renal allografting to improve allograft survival. Since host modifications that improve the outcome of an allograft might be associated with a decreased ability of the host to control cancer growth, the relationship between blood transfusions and the outcome of 146 Dukes' stages A, B, and C colon cancers treated by resection during the years 1974 to 1979 was studied. It was found that 65 patients (45%) had been transfused and that at 5 years, overall survival was significantly better in the nontransfused patients compared to the transfused patients (0.68 and 0.51 5-year product limit survival fractions respectively; P = 0.03 for unadjusted log-rank comparison of entire survival curves). Relative risk of death due to cancer in transfused patients versus nontransfused patients was 2.3 (P = 0.05) when controlled for sex, age, stage, histologic differentiation, cancer location, and pre-resection hemoglobin level using Cox regression analysis. Thus, blood transfusion appears to be an additional important prognostic variable. The hypothesis suggested but not proven by these data that the outcome for some malignancies may be related to the immunomodulating effects of blood transfusions needs further study.

Aged↗
PubMed1985

Blood transfusions and survival after lung cancer resection.

The immunosuppressive effects of blood transfusions in renal transplantation patients are now well documented. The question arises as to whether the possible immunosuppressive effects of blood transfusions in cancer patients cause a more favorable host environment for tumor growth. One hundred fifty-five patients undergoing resection for lung carcinoma were analyzed retrospectively, and it was shown that the use of blood transfusions was associated with a significant decrease in survival time in patients undergoing curative resection of lung carcinoma despite multivariate adjustments for age, sex, cell type, right lung versus left lung location, type of operation, and stage. This association supports, but does not prove, the hypothesis that blood transfusions, possibly through an immunosuppressive mechanism, are responsible for a poorer prognosis in patients who undergo resection for carcinoma of the lung.

Adenocarcinoma↗