Biomedical subjects

Garth H Rauscher

Publications and source records attributed to Garth H Rauscher.

10 recordsLinked to original sources

PubMed2006

Common referent versus shifting referent methods when using case-control data to examine patterns of incidence across multiple exposure variables.

PURPOSE: In case-control studies, when odds ratios estimate rate ratios or risk ratios, trends in odds ratios can reflect trends in incidence in the underlying population. METHODS AND RESULTS: In this report, we use an empirical example and hypothetical data to compare two methods ("common referent" and "shifting referent") for calculating odds ratios from case-control data across multiple exposure variables. With common referent methods, a single independent variable is constructed from the joint distribution of all exposure variables. With shifting referent methods, each stratum-specific trend has its own referent. CONCLUSIONS: Using examples involving a single ordinal "trend" variable and a dichotomous "stratification" variable, we show that common referent odds ratios will reflect the pattern of incidence in the underlying population, whereas odds ratios calculated using shifting referent methods will not.

Case-Control Studies↗

PubMed2005

Occupation, hobbies, and acute leukemia in adults.

Occupational and industrial exposures have been implicated in the etiology of leukemia, yet uncertainty remains regarding potential high risk occupations. We examined the associations between self-reported occupations and hobbies and acute leukemia risk using data from 811 cases and 637 controls participating in a case-control study in the U.S. and Canada. We found that several occupations may increase the risk of acute leukemia, particularly occupations related to petroleum products, rubber, nuclear energy, munitions, plastics, and electronics manufacturing. Differences were noted according to histological type. Other occupations and hobbies were not clearly associated with risk.

Acute Disease↗

PubMed2005

Baseline predictors of initiation vs. maintenance of regular mammography use among rural women.

BACKGROUND: Predictors of regular mammography screening over many years have not often been examined prospectively. We used data from baseline (1993-1994), first (1996-1997), and second follow-up (2000) interviews with 336 White and 314 African-American rural women in the North Carolina Breast Cancer Screening Program to evaluate baseline factors predictive of regular mammography use over 7 years. METHODS: We defined regular mammography use as a recent mammogram (past 2 years) at all three interviews. Using binomial and logistic regression models adjusted for age, we examined factors associated with initiation (for women without prior regular use) and maintenance (for women with prior regular use) of mammography. RESULTS: Younger age and White race were predictive of initiation of regular mammography use. Physician recommendation was the strongest predictor of both initiation and maintenance of regular mammography use. Positive mammography attitudes and fewer personal barriers were strongly associated with initiation but not with maintenance. CONCLUSIONS: Increased contact with providers and greater support for screening mammograms by providers could have an important impact on rural women initiating and maintaining regular mammography screening. Special efforts are needed to prompt rural African-American women and those over age 65 to initiate screening, since once they start they are likely to continue.

Adult↗

PubMed2005

Validating cancer histories in deceased relatives.

BACKGROUND: A family history of cancer is a marker of familially shared genetic and environmental risk factors for cancer but is subject to inaccurate and biased reporting. METHODS: In a case-control study of adult acute leukemia, we examined the accuracy of cancer reports in deceased first-degree relatives using death certificates and the National Death Index (NDI). We submitted information on 1058 deceased relatives to the NDI or civil vital statistics registries. Social security numbers were not available and identifying information was incomplete. RESULTS: A death certificate was located for 70% of records sent to state registries but for only 32% of records submitted to the NDI. Death certificates confirmed 95% of relatives reported to be cancer-free and 83% of those reported to have any form of cancer. Confirmation of cancer of specific sites ranged from 50% for breast cancer and 54% for leukemia to 86% for prostate cancer. CONCLUSIONS: State searches may be preferable to the NDI when identifying information is incomplete.

Acute Disease↗

PubMed2004

Hair dye use and risk of adult acute leukemia.

Certain chemicals in hair dyes are known animal carcinogens. Darker, more permanent, and earlier dye formulations may be more carcinogenic than other dye types. For 769 adult acute leukemia cases and 623 population-based controls in a US and Canadian case-control study in 1986-1989, the authors asked separately about use of permanent and nonpermanent (semipermanent and temporary) hair dye use. Use was reported by 45% of women and 6% of men. There was a modest positive association for ever use of permanent dyes (odds ratio = 1.5, 95% confidence interval: 1.0, 2.1), which was stronger for long duration (15 or more years) of use (odds ratio = 1.8, 95% confidence interval: 1.0, 3.1). The greatest odds ratio was for 15 or more years of using hair dyes up to six times per year (odds ratio = 2.4, 95% confidence interval: 1.0, 5.8); the corresponding odds ratio for use six or more times a year was lower, suggesting the possibility of misclassification of dye type among frequent users, since nonpermanent dyes tend to be used more frequently than permanent dyes. Nonpermanent dyes were not associated with risk. Long duration of permanent dye use may have a larger impact on the risk of adult acute leukemia and other hematopoietic cancers than prior epidemiologic data suggest.

Acute Disease↗

PubMed2004

Alcohol intake and incidence of de novo adult acute leukemia.

In a case-control study of adult acute leukemia we defined alcohol intake as either non-regular (<1 drink per week), light (1-5 drinks per week), moderate (6-8 drinks per week) or heavy (>8 drinks per week). An inverse association was found for light and moderate beer intake (RR = 0.58; 95% CI: 0.44, 0.76). In contrast, a positive association was found for moderate and heavy wine intake (RR = 2.1; 95% CI: 1.2, 3.8). Divergent results might reflect the effect of different nutrients in beer and wine, unmeasured confounding, or differing impacts of selection bias on these associations.

Acute Disease↗

PubMed2004

Relation between intervention exposures, changes in attitudes, and mammography use in the North Carolina Breast Cancer Screening Program.

OBJECTIVE: Many past interventions have been based on the assumption that improving attitudes about mammography can increase mammography use. We studied changes in breast cancer and mammography attitudes over time in mediating the effect of intervention exposures on mammography use in the North Carolina Breast Cancer Screening Program. Data came from interviews with a cohort of 331 black women who said they had heard of mammography at baseline interview. METHODS: We created scores and score changes for mammography (7 items) and breast cancer (11 items) attitudes at baseline (1993-1994) and follow-up interviews (1996-1997). We modeled intervention exposures, attitude changes, and mammography use in linear risk and logistic regression. Intervention exposures were defined for mammography discussion with a project lay health advisor ("LHA advice"), mammography discussion with anyone besides a doctor or nurse, and project awareness. RESULTS: Positive change in mammography attitudes was associated with intervention exposures and mammography use and appeared to account for a large percentage (34-98%) of the effect of mammography discussion variables on increased mammography use. Greatest effect of attitude improvement was found for women without a recent mammogram at baseline and with the least positive baseline attitude scores. CONCLUSION: Using cohort data enabled us to examine the role of attitude change over time on mammography use. Breast cancer screening programs should target women with the most negative mammography attitudes and the least mammography use to start with and concentrate their messages on improving attitudes specific to mammography rather than improving attitudes about breast cancer risk.

Adult↗

PubMed2003

Is family history of breast cancer a marker of susceptibility to exposures in the incidence of de novo adult acute leukemia?

The risk factors for adult acute leukemia incidence have been difficult to establish. Family history of cancer might interact with environmental exposures to produce associations that are otherwise difficult to detect. In addition to family history of leukemia or other hematopoietic cancers, family history of breast cancer could be a marker of susceptibility, because leukemia and breast cancer are known to cluster in families that have specific germ-line mutations. In a population-based case control study of 779 incident adult acute leukemia patients and 625 controls, we estimated the relative risk for exposed individuals with a family history compared with unexposed individuals without a family history (RR(11)), along with a measure of interdependence, the interaction contrast ratio. Combined with a family history of breast cancer, ever-smoking [RR(11) = 2.4, 95% confidence interval (CI): 1.2-4.8], general solvent exposure (RR(11) = 1.9, 95% CI: 1.1-3.4), aromatic hydrocarbon exposure (RR(11) = 3.8, 95% CI: 1.1-14), and diagnostic ionizing radiation exposure (RR(11) = 2.1, 95% CI: 1.2-3.8) were all associated with increased incidence. Furthermore, there was no increased incidence associated with any of these exposures in the absence of a family history of breast cancer and no increased incidence for family history of breast cancer in the absence of exposures. The pattern of relative risks strongly suggested synergy across exposures. Family history of breast cancer might be a marker of susceptibility to a range of leukemia risk factors, whose effects are generally weak or nonexistent when considered alone.

Adolescent↗

PubMed2002

Family history of cancer and incidence of acute leukemia in adults.

Family history of cancer may represent shared genetic and environmental risk factors for leukemia. The authors examined associations of first-degree family history of cancer with adult acute leukemia incidence by using data on 811 patients (or their proxies) identified at diagnosis and 637 population-based controls in the United States and Canada during 1986-1990. For proxy-interviewed patients, relative risks were elevated for family history of any cancer (relative risk = 1.7, 95% confidence interval (CI): 1.3, 2.4), hematopoietic cancer (relative risk = 1.8, 95% CI: 1.1, 3.0), leukemia (relative risk = 2.4, 95% CI: 1.3, 4.6), and breast cancer (relative risk = 1.7, 95% CI: 1.0, 3.0) but not for colorectal, prostate, or lung cancer. For self-interviewed patients, family history of hematopoietic cancer was inversely associated with leukemia incidence (relative risk = 0.6, 95% CI: 0.4, 1.1). Regardless of patient interview type, history of breast cancer in sisters was positively associated with adult acute leukemia, whereas history of breast cancer in mothers was not. The role of family history of cancer in leukemia etiology is unclear because of differential reporting by patients and proxies. Specifically, self-interviewed patients may underreport cancer in their first-degree relatives. Associations between family history of breast cancer and leukemia incidence may be the result of unmeasured, shared etiologies specific to these cancers.

Adult↗

PubMed2002

How consistently do women report lifetime mammograms at successive interviews?

BACKGROUND: Little data exist on the reliability of self-reported regular mammography use measures. We used data from two successive interviews of 892 women aged 50 to 74 years without a history of abnormal mammograms to investigate how consistently women report their lifetime number of mammograms. METHODS: We added an estimated number of mammograms obtained between interviews to the baseline report to create a revised baseline report for comparison with the follow-up report. We then examined the correlation in paired reports, the level of agreement between paired reports, and factors associated with consistent reporting. RESULTS: Spearman rank correlation between paired reports was 0.73. Agreement between paired reports dropped with increasing lifetime number of mammograms. After adjustment for mammography use, women's characteristics did not appear to be strongly associated with consistent reporting. CONCLUSIONS: Self-reported lifetime number of mammograms is a reasonably consistent measure for younger women or women with less mammography experience, but it is less reliable for women with long mammography histories. In these women, it may be useful to distinguish those who obtain regular screening from those who do not. Assessing reliability as well as validity for other measures of regular mammography use will allow additional measures to be identified.

Black or African American↗