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Biomedical subjects

R M Mickey

Publications and source records attributed to R M Mickey.

At least 19 recordsLinked to original sources
PubMed2001

Identifying women at risk for inherited breast cancer using a mammography registry.

BACKGROUND: Women at risk for inherited breast cancer have been identified for intervention studies through newly diagnosed relatives or from volunteers with a family history. This pilot study tested the use of a mammography registry to identify women at risk. METHOD: Fifty women with first-degree relatives diagnosed as having breast cancer before age 45 were randomly selected from the Vermont Breast Cancer Surveillance System. Thirty-three women (66%) completed a phone interview that included a three-generation family pedigree of breast and ovarian cancers. RESULTS: Fifty-one percent of the women were at higher risk for inherited breast cancer based on the family history. Eighteen percent of the first-degree relatives' breast cancers were pathologically confirmed. CONCLUSION: Mammography registries that collect similar family history data may be used to identify women at risk for inherited breast cancer. Many intervention studies would require improved methods to obtain pathologic confirmation.

Adult↗
PubMed1998

Assessment of self-reward strategies for maintenance of breast self-examination.

This study examined the relative impact of different self-reward strategies on maintenance of breast self-examination (BSE) practice among 1649 women trained to do BSE. Training groups were randomized into four conditions: (a) self-reward instructions and materials delivered at the end of the BSE training session; (b) self-reward suggestions delivered through the mail each month, contingent upon the BSE performance; (c) external monetary rewards and self-reward suggestions delivered through the mail each month on an intermittent schedule, contingent upon BSE practice; and (d) a no-reward control condition. Follow-up assessments 12 months following training revealed a pattern of evidence in support of the benefits of external monetary rewards and self-reward prompts on BSE frequency and quality; however, it is likely that the value of that condition lies in the external reward component.

Adolescent↗
PubMed1995

Breast cancer screening and associated factors for low-income African-American women.

BACKGROUND: Recent reports suggest that much of the difference in breast cancer survival between African-Americans and whites could be reduced through greater access to and use of screening by African-American women. Few community-based studies have addressed screening-related issues among low-income African-American women. METHODS: A simple random sample of households was drawn; a total of 585 women of age 40 or older were interviewed in their homes (response rate = 75%). Women were grouped into four stages of adoption of screening: participated regularly, participated nonregularly, heard of but never participated in screening, or never heard of it. Bivariate analyses were used to describe relations between screening (mammography, clinical breast examination, and breast self-examination) and mediating variables. RESULTS: Ninety percent of the women were not getting regular mammography screening, 36% had heard of but had never had mammography, and 33% had never heard of mammography. Strong associations were noted with predisposing, enabling, and reinforcing factors inhibiting screening at each stage of adoption. CONCLUSIONS: For women who had heard of, but who were not getting, regular screening, recommendations were made for improving screening procedures in primary care practices. For women who had never heard of screening, coordinated community and primary care interventions were recommended for moving them toward regular 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

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

The magnitude and variability of design effects for community intervention studies.

Despite inadequate replication of treatment and comparison groups in community intervention studies, suitable estimates of variance can be obtained by multiplying the simple random sampling variance by a design effect, which can be estimated from other sources. To study the stability of these estimates, the authors performed a detailed investigation of the magnitude and sources of variability of design effects for age-adjusted mortality rates for selected causes of death separately for each of 44 US states. The authors made use of age-sex-race-county-specific data from the Compressed Mortality File generated by the National Center for Health Statistics. Design effects were calculated as the ratio of a cluster (county) sampling variance to the simple random sampling variance. The effects of sex, state, and year on the magnitude of the design effects were investigated by analysis of variance. Design effects were 2.33, 1.66, 1.24, 1.08, and 1.06 for ischemic heart disease, stroke, and cancers of the lung, breast, and colon, respectively. The largest source of variability was state; 35-70% of this variability could be attributed to the states' differing population sizes. The effect of sex was minimal. These results are relevant to the planning and analysis of community intervention studies.

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↗
PubMed1989

Application of a two-stage random effects model to longitudinal pulmonary function data from sarcoidosis patients.

We applied a two-stage random effects model to pulmonary function data from 31 sarcoidosis patients to illustrate its usefulness in analysing unbalanced longitudinal data. For the first stage, repeated measurements of percentage of predicted forced vital capacity (FVC%) from an individual were modelled as a function of time since initial clinical assessment. At the second stage, parameters of this function were modelled as a function of certain patient characteristics. We used three methods for estimating the model parameters: maximum likelihood; empirical Bayes; and a two-step least-squares procedure. Similar results were obtained from each, but we recommend the empirical Bayes, since it provides unbiased estimates of variance components. Results indicated that deterioration in FVC% is associated with a higher initial FVC% value and large numbers of both total cells and eosinophils in bronchoalveolar lavage at the initial assessment. Improvement is associated with higher values of pulmonary Gallium uptake at initial assessment and race. Blacks are more likely to improve than whites.

Adolescent↗
PubMed1989

The impact of confounder selection criteria on effect estimation.

Much controversy exists regarding proper methods for the selection of variables in confounder control. Many authors condemn any use of significance testing, some encourage such testing, and other propose a mixed approach. This paper presents the results of a Monte Carlo simulation of several confounder selection criteria, including change-in-estimate and collapsibility test criteria. The methods are compared with respect to their impact on inferences regarding the study factor's effect, as measured by test size and power, bias, mean-squared error, and confidence interval coverage rates. In situations in which the best decision (of whether or not to adjust) is not always obvious, the change-in-estimate criterion tends to be superior, though significance testing methods can perform acceptably if their significance levels are set much higher than conventional levels (to values of 0.20 or more).

Epidemiologic Methods↗
PubMed1989

Biphasic cellular and tissue response of rat lungs after eight-day aerosol exposure to the silicon dioxide cristobalite.

Cristobalite is a crystalline silicon dioxide that elicits pulmonary inflammation and fibrosis in humans and experimental animals. Exposure of rats to aerosols of respirable cristobalite for 8 days led to a rapid influx of neutrophils and macrophages into alveolar and tissue compartments of the lung followed by a more gradual accumulation of T lymphocytes. This inflammatory response persisted throughout 52 weeks after the end of the exposure. For some variables studied there appeared to be a cyclical nature to the response. Statistical analysis of alveolar cell populations and lung tissue weight, protein, and hydroxyproline showed significant time-dependent fluctuations. Histologic analysis revealed a progressive deposition of collagen and type II cell hyperplasia centered on airways, however, there appeared to be some correlation between fluctuations in alveolar cell populations and overall tissue pathology. The observed cellular and biochemical fluctuations and the persistence of the inflammatory response may be due to the presence of silica in the lung, which serves as a source of repetitive stimulation of lung cells.

Aerosols↗
PubMed1988

An immunogenetic study of suppressor cell activity in autoimmune chronic active hepatitis.

Some patients with autoimmune chronic active hepatitis as well as their disease-free first degree relatives show decreased suppressor cell activity of peripheral blood T lymphocytes. Studies were therefore undertaken in families ascertained by the presence of a single chronic active hepatitis patient to determine if this abnormality of immune regulation represents a genetic phenotype simply controlled by a gene or genes at a putative disease susceptibility locus and, further, if this locus showed linkage to either the HLA or the immunoglobulin constant region loci. In addition to determining circulating autoantibody status and genotyping for HLA and immunoglobulin allotypes, suppressor T cells were evaluated by surface markers and by determining their ability to suppress IgG secretion in vitro. The results suggest that immunoregulatory dysfunction in autoimmune chronic active hepatitis is a familial abnormality, but that this abnormality occurs independent of circulating autoantibody status and of the segregation of genes for HLA or immunoglobulin allotypes.

Antigens, Differentiation↗
PubMedDate not supplied

Immunogenetic studies of autoimmune chronic active hepatitis: HLA, immunoglobulin allotypes and autoantibodies.

The strategy of assigning a surrogate phenotype, defined as the presence of antinuclear and/or antismooth muscle antibodies to disease-free first degree relatives of index cases was used to search for a postulated disease susceptibility gene in autoimmune chronic active hepatitis. In addition to determining circulating autoantibody status, 10 patients, 51 first-degree relatives and 6 spouses of index chronic active hepatitis patients, each ascertained by the single patient, were genotyped for HLA (A, B and DR loci) and immunoglobulin allotype (G1m, G2m, G3m and A2m loci) haplotypes. Among the 10 chronic active hepatitis patients, 6 had HLA haplotypes B8 and DR3, and 3 of these patients had, in addition, the immunoglobulin allotype haplotype Gm a,x;g. Circulating autoantibodies defining the surrogate phenotype was found in 39% of the first-degree relatives. However, segregation analysis offered no support for either single autosomal dominant or recessive inheritance for the autoantibody-positive phenotype. Linkage between the postulated disease susceptibility locus and either the HLA (Chromosome 6) or immunoglobulin (Chromosome 14) locus was excluded by several analyses. Furthermore, logistic regression indicated that neither immunogenetic marker was statistically associated with autoantibody positively in these families. Therefore, despite the occurrence of autoantibody positivity in first-degree relatives of autoimmune chronic active hepatitis patients, we found no evidence that this trait has a simple genetic basis, or that it is an alternative manifestation of a postulated disease susceptibility gene for chronic active hepatitis.

Antibodies, Antinuclear↗
PubMedDate not supplied

Reliability of self-reported breast screening information in a survey of lower income women.

BACKGROUND: Self-reported behavior is widely used to estimate the prevalence of breast cancer screening and to evaluate programs for promoting screening, but detailed studies of reliability have not previously been performed. METHODS: Reliability was assessed by comparing responses to questions about screening behavior from repeat personal interviews of 382 women age 40 and older living in low-income census tracts of two Florida communities. Reliability was assessed using Pearson's correlation (r) and kappa (kappa) coefficients. RESULTS: Estimated reliabilities were kappa = 0.38 for "ever had clinical breast examination," kappa = 0.82 for "ever had mammogram," kappa = 0.65 for "mammogram in past year," r = 0.54 for "date of last mammogram," and r = 0.72 for "number of mammograms." The dates of last mammogram reported at the two interviews agreed within 1 month for 64% of the women, while the dates of last clinical breast examination agreed within 1 month for 50% of the women. Reliability of "ever had mammogram" was significantly related to demographic variables. CONCLUSIONS: Women reliably report ever having mammography, but information about timing and frequency has lower reliability. The results have implications for breast screening research because measurement error affects the precision of estimates and the sample sizes needed to detect program effects.

Adult↗
PubMedDate not supplied

Three-year prospective adherence to three breast cancer screening modalities.

BACKGROUND: This study prospectively examined rates of adherence to mammography, clinical breast examination (CBE), and breast self-examination (BSE) in a cohort of women over 3 years to determine whether participation in BSE influenced participation in the other two screening modalities. METHODS: Women ages 51 and older (n = 450) who attended a small group educational session to learn BSE and to hear about CBE and mammography guidelines were assessed annually by telephone for 3 consecutive years to determine their subsequent breast cancer screening behavior. RESULTS: Annual CBE and mammography screening are highly positively associated. Regular performance of BSE has a modest positive association with both CBE and mammography adherence over time. CONCLUSIONS: Women who perform BSE regularly over time may be more likely to adhere to the other breast cancer screening guidelines.

Aged↗