Biomedical subjects

S Freels

Publications and source records attributed to S Freels.

At least 37 records · Page 2Linked to original sources

PubMed1998

Survival rates in patients with primary malignant brain tumors stratified by patient age and tumor histological type: an analysis based on Surveillance, Epidemiology, and End Results (SEER) data, 1973-1991.

OBJECT: The authors present population-based survival rate estimates for patients with malignant primary brain tumors based on an analysis of 18 years of data obtained from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. METHODS: Estimates of survival rates at 2 and 5 years after diagnosis for patients with specific histological tumor types were categorized by patient's age at diagnosis (< or = 20 years, 21-64 years, and 65 years or older) and by the time period in which the patients were diagnosed (1973-1980, 1981-1985, 1986-1991). Where appropriate, survival estimates were adjusted for changing patterns in the mean age at diagnosis. CONCLUSIONS: The authors observed a pattern of declining survival rates in patients with increasing age of the patient at diagnosis for most histological groups and overall improvements in survival rates of patients across these time periods adjusting for age at diagnosis. There were improvements in 2- and 5-year survival rates over the three time periods for children and adults with medulloblastoma and for adults with astrocytoma and oligodendroglioma. Improvements in survival rates for pediatric patients with medulloblastoma have leveled off in the most recent time period, and gender differences in survival rates for patients with this tumor, which were present in the 1970s, have disappeared. Clinically significant improvements in survival rates were not apparent in patients aged 65 years and older. Changes in diagnostic and treatment procedures since the mid-1970s have resulted in improved survival rates for patients diagnosed as having medulloblastoma, oligodendroglioma, and astrocytoma, controlling for age at diagnosis. Glioblastoma multiforme continues to be the most intractable brain tumor.

Adult↗

PubMed1998

Factors associated with survival in patients with meningioma.

OBJECT: To explore factors affecting the survival rate in patients with meningiomas, the authors used the National Cancer Data Base (NCDB), which includes tumors from approximately 1000 hospitals participating in the American College of Surgeons tumor registry program. METHODS: Analysis included over 9000 cases diagnosed from 1985 to 1988 and 1990 to 1992. Survival estimates were computed and prognostic factors were identified using a proportional hazards model. The overall 5-year survival rate was 69% and it declined with patient age. This rate was 81% in patients aged 21 to 64 years and 56% for patients 65 years of age or older. When patients were grouped by the histological type of their tumors, those with benign tumors had an overall 5-year survival rate of 70%, whereas the overall 5-year survival rates in patients with atypical and malignant meningiomas were 75% and 55%, respectively. Prognostic factors for benign tumors included age at diagnosis, tumor size, whether treated surgically, hospital type, and radiation therapy; for malignant tumors, the prognostic factors included: age at diagnosis, whether treated surgically, and radiation therapy. These factors were statistically significant. The 5-year rate for recurrence of symptoms (regardless of the method of treatment) was 19.2% for those with benign tumors and 32.4% for those with malignant tumors. In patients whose benign tumor had been completely removed, the 5-year rate of tumor recurrence was 20.5%. CONCLUSIONS: Although not population-based, the NCDB has the potential for providing pertinent information regarding patient characteristics and methods of treatment for benign, as well as malignant, brain tumors.

Activities of Daily Living↗

PubMed1997

The relation of age, race, and gender to the subsite location of colorectal carcinoma.

BACKGROUND: Characteristics that determine the anatomic site within the colorectum where carcinoma is most likely to occur would be useful in choosing optimal modalities for cancer screening and in the study of etiology. The aim of this study was to identify any association of gender, race, or age with colorectal carcinoma in the proximal or distal colorectum. METHODS: A descriptive, population-based epidemiologic study was conducted on colorectal carcinoma (CRC) cases identified through the Illinois Tumor Registry. Among CRC patients diagnosed between 1986 and 1991, age at diagnosis (40-90 years), gender, white or African American race, and subsite of CRC location were identified. Incidence rates were determined with demographic data from the 1990 Illinois census. Logistic regression was used to identify significant subsite specific risk factors for CRC. RESULTS: During the study period, 38,931 cases of CRC occurred in Illinois among whites and African Americans between the ages of 40 and 90 years. Age, race, and gender were independently significantly associated with both proximal and distal CRC risk (P < 0.0001). The greatest risk for white males was for distal CRC, followed by the risk for African American males of developing CRC in the distal colorectum. African Americans were more likely than whites to develop proximal CRC (odds ratio [OR] = 1.19), whereas whites were more likely to have distal CRC than African Americans (OR = 1.26). Regarding the development of CRC anywhere in the colorectum, male incidence rates adjusted for age and race were greater than rates for females (OR = 1.32 for proximal and 1.68 for distal). CONCLUSIONS: The division of the colorectum anatomically in these analyses at the junction of the descending and sigmoid colon, and including the rectum above the anal canal with "distal" CRC, demonstrated a predominance of African Americans among those at risk for proximal colon carcinoma and a predominance of white males among those at risk for distal CRC; these predominances were clearer than in previous reports. These findings may have a role in the selection of optimal CRC screening strategies for each gender or racial group.

Adult↗

PubMed1997

Assessment of painful episode frequency in sickle-cell disease.

Frequency of painful episodes in sickle-cell disease is considered to be related to clinical severity and possibly to other aspects of the disease. Measurements of frequency often include only hospital-related or more severe, longer-lasting episodes. Since painful episodes, however, may regularly occur in nonhospital settings or be shorter-lasting with possible different pathologic effects, we measured all painful episodes in 10 adults with sickle-cell disease for 1.0-3.8 years, using a daily questionnaire. The results were related to other indices of disease severity and to possible precipitating factors, such as cold weather and menses. Sixty-one percent (on average) of the total number of episodes (243) were nonhospital-related, and 33% (on average) were shorter-lasting. Episode frequencies, whether determined as total, hospital-related, nonhospital-related, or shorter-lasting, were not related to each other or to other indicators of disease severity. The highest incidence of episode frequency occurred in the winter. The association of episodes with menses was moderately close in individual patients. The findings suggest that nonhospital-related painful episodes and shorter-lasting episodes may contribute significantly to episode frequency. Measurement of frequency of all painful episodes would require consideration when evaluating episode frequency and its relationship to disease severity, to possible precipitating factors of episodes, and to treatment of the disease, and for study of the natural course of the disease.

Adult↗

PubMed1997

Lead exposure in ironworkers.

In adults, lead toxicity is most commonly caused by occupation in a lead industry. Whereas lead toxicity has been described in workers who are involved in bridge rehabilitation, as of this date there has been no systematic evaluation published regarding the conditions responsible for lead toxicity in ironworkers. This is a report of a study designed to identify risk factors for elevated blood-lead levels in ironworkers. One hundred fifty members of a 2,400-member local ironworkers union volunteered to have their blood drawn for lead and zinc protoporphyrin analysis and to complete a questionnaire regarding demographics, health, and occupation. The relationships between these variables and blood-lead level were analyzed using student's t-test, chi-square, and logistic regression. Current work on a lead job, rivet busting as the predominant job task, and cigarette smoking were all found to be significantly associated with elevated blood-lead level. Whereas cigarette smoking and current work with lead have been previously identified as risk factors for toxicity, interventions to prevent lead toxicity in ironworkers should also focus on work practices during rivet busting.

Adult↗

PubMed1997

Occupational lead exposure and hearing loss.

Studies of adults, children, and laboratory animals suggest an association between lead exposure and hearing loss. A causal relationship might direct mandated medical surveillance of lead-exposed workers to include audiometric testing. A cross-sectional, computerized dataset was obtained from a private occupational health screening company to examine the relationship between blood lead level and hearing loss. Audiometry and blood lead results were available for 183 workers. A statistically significant correlation was found between blood lead level and an elevated hearing threshold at 400 Hz (P = 0.03); no other frequencies showed such a correlation. This finding suggests either an interaction between nose exposure and lead, interaction of other exposure factors (such as cigarette smoking), or that factors other than biomechanical ones render the organ of Corti more susceptible at 4000 Hz. Further evaluation of these questions should be undertaken. Computerized databases created for worker surveillance may be a source for data useful for examining other causal connections in occupational settings.

Adult↗

PubMed1997

Evaluation of internal alpha-particle radiation exposure and subsequent fertility among a cohort of women formerly employed in the radium dial industry.

This study examined the effect of internal exposure to alpha-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of alpha particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of gamma-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility.

Abortion, Spontaneous↗

PubMed1996

Applying the realized probability of dying to cancer survival.

Age comparisons of survival in cancer cohorts generally utilize relative survival rates, which are based on indicators of the probability of survival for a given number of years after diagnosis. Cancer relative survival rates for the same number of years tend to decline as age at diagnosis increases. However, the same number of years of survival reflects higher relative longevity at older ages than at younger ages. The realized probability of dying (RPD) is a survival measure that expresses individual survival time after diagnosis relative to the survival distribution of an age-, race-, and sex-specific reference population, in effect weighing individual survival time more heavily as age at diagnosis increases. The purpose of this study was to apply the RPD as a survival measure in cancer epidemiology. Two cohorts of cancer patients, white males with prostate cancer and white females with breast cancer, aged 55 years and over at diagnosis, were followed for 15 years. Although older subjects survived less time after diagnosis than younger subjects, they achieved more favorable RPD values. We present survival analysis methods for analyzing the RPD in this population, an approach not previously used with this measure. The implications for use of the RPD in cancer epidemiology are discussed.

Breast Neoplasms↗

PubMed1996

An international collaborative study of the effects of coinfection with human T-lymphotropic virus type II on human immunodeficiency virus type 1 disease progression in injection drug users.

To determine whether human T-lymphotropic virus (HTLV) type II coinfection affects progression of human immunodeficiency virus type 1 (HIV) infection, longitudinal data on 370 HIV-infected injection drug users (IDUs) with known HIV seroconversion dates from four cohort studies were pooled. HTLV infection was determined by EIA and confirmed and typed by Western blot. Proportional hazards models were used to determine whether HTLV-II infection was associated with AIDS or AIDS-related mortality. Regression analyses were used to compare declines in CD4 cell percents in singly and dually infected persons. Of 370 IDUs, 61 (16%) were HTLV-II-coinfected. During follow-up, 43 (12%) developed and 24 (6%) died of AIDS. HTLV-II coinfection was not associated with progression to AIDS (relative hazard [RH], .82; 95% confidence interval [CI], 0.34-1.94]) or AIDS mortality (RH, 1.69; 95% CI, 0.62-4.60). Rates of decline in CD4 cell percent were similar in singly and dually infected IDUs. These results suggest that HTLV-II does not affect the progression of HIV infection.

Acquired Immunodeficiency Syndrome↗

PubMed1995

Attitudes and practices for smoking cessation counseling by provider type and patient age.

Attitudes and self-reported practices for smoking cessation counseling among 145 providers at a health maintenance organization were compared among two provider groups, physicians/nurse practitioners and registered/licensed practical nurses, and across three patient age groups, < 50, 50-64, and > or = 65. Smoking cessation attitudes did not differ by provider type but they did differ by patient age, especially among the registered/licensed practical nurses, whose attitudes were least favorable for the oldest smokers (> or = 65). While smoking cessation practices did not differ by patient age, they did differ by provider type. Self-reported performance of the 4 As of smoking cessation practice (Ask, Advise, Assist, Arrange) was more frequent among the physicians/nurse practitioners than among the registered/licensed practical nurses. However, among both groups, asking and advising practices were reported more often than were assisting and arranging. In all cases, different attitudes were correlated with different practice behaviors for the two provider groups. Also, there were more significant correlations between age-specific attitudes and practices among the registered/licensed practical nurses than among the physicians/nurse practitioners. This was true especially regarding the oldest patients. The findings suggest a need for provider education, especially among registered/licensed practical nurses, about the benefits of smoking cessation for patients of all ages and the potential effectiveness of provider-based intervention strategies that are targeted toward specific age groups. The findings also suggest that assisting and arranging practices in particular need improvement among all types of providers.

Adult↗

PubMed1995

Age and smoking cessation behaviors.

BACKGROUND: Predictors of smoking cessation behaviors during a 3-month period were examined among smokers in three age groups: 18 to 29, 30 to 49, and 50 years or older. METHODS: Using random-digit dialing, telephone interviews were completed with 1,644 smokers in the Chicago metropolitan area at baseline and at a 3-month follow-up. Multiple logistic regression was used to identify factors that predicted trying to quit smoking and quitting smoking within each age group and by stage of readiness to quit smoking. RESULTS: There were no significant differences by age in trying to quit smoking or in quitting smoking among smokers in the contemplation or preparation stages. However, there were important age differences in the factors that predicted those behaviors. In general, different factors predicted smoking cessation behaviors in each age group at each of three stages of the smoking cessation process (contemplation, preparation, and action). Also, within each age group, different factors predicted the behavior at each stage. CONCLUSIONS: The findings suggest that smokers of all ages are equally appropriate targets for smoking cessation interventions. Moreover, there are important age-related differences among smokers over the course of their smoking careers that should be considered when planning and implementing smoking cessation interventions.

Adolescent↗

PubMed1995

CT and MRI findings among African-Americans with Alzheimer's disease, vascular dementia, and stroke without dementia.

We compared CT and MRI findings among 78 Alzheimer's disease (AD), 66 vascular dementia (VaD), and 41 stroke without dementia (SWD) African-American patients to identify possible neuroimaging indicators of dementia. The patients with AD and VaD were generally older and less educated than those with SWD. VaD and SWD patients had a higher frequency of cardiovascular disease risk factors than those with AD. In multivariate analysis, the CT data showed that the presence of white matter lesions, nonlacunar infarcts, and left subcortical infarcts were predictors of VaD when compared with AD, whereas atrophy of the third ventricle and equal distribution of white matter lesions distinguished VaD from SWD. On MRI, atrophy of the temporal sulci, temporal horns, and the third ventricle, and right hemisphere infarcts, distinguished AD from VaD, while atrophy of the third ventricle differentiated VaD from SWD. These data suggest that atrophy, especially at the level of the third ventricle, presence of infarcts, and white matter lesions may be useful predictors of dementia subtype. Furthermore, the qualitative CT and MRI findings among our African-American patients were similar to those reported in other dementia studies.

Black or African American↗

PubMed1995

Neuroepidemiology of vascular and Alzheimer's dementia among African-American women.

To better understand risk factors for Alzheimer's disease and vascular dementia, demographic, medical, and other epidemiological factors were compared for 83 African-American women with Alzheimer's disease and 46 with vascular dementia. Overall, the risk-factor profiles for Alzheimer's disease and vascular dementia were similar to those in other studies. However, Alzheimer's patients had a high frequency of hypertension and a relatively high frequency of diabetes mellitus. The presence of such risk factors raises the possibility that there is a vascular component to the dementia in these African-American women with Alzheimer's disease. Neuropathological studies are needed to help answer this question.

Aged↗

PubMed1994

Age and readiness to quit smoking.

The relationship between planning to quit smoking within the next 3 months and demographic characteristics, smoking history, attitudes and beliefs about smoking cessation, and motivation was analyzed among smokers in three age groups: 18 to 29, 30 to 49, and 50 years or older. Using random-digit dialing, telephone interviews were completed with 2,353 smokers before initiating a self-help, minimal-contact intervention in the Chicago metropolitan area. Multiple logistic regression was used to identify factors that predicted planning to quit within the next 3 months. The two youngest age groups were most likely to have attitudes favorable to being ready to try to quit smoking (they were more concerned about health effects of smoking, perceived a greater reduction in the likelihood of getting lung cancer, were more determined to quit, and were more confident in their ability to quit). Among all three age groups, one-fourth or less planned to quit within the next 3 months, and desire to quit was the strongest predictor in each group. Among smokers who planned to quit someday, the oldest were most likely to plan to quit within the next 3 months. The findings show that there are important age-related differences in readiness to quit smoking that should be considered when planning and evaluating smoking cessation interventions.

Adult↗

PubMed1994

Comparison of dementia criteria: sensitivity and specificity testing among African American patients.

We compared the sensitivity and specificity of recently proposed general dementia, vascular dementia, and Alzheimer's disease criteria using the DSM III-R as the 'gold standard' among 61 elderly African American patients. There were 10 patients with vascular dementia, 20 with Alzheimer's disease and 31 controls. Comparison of the sensitivity and specificity of the various criteria showed that with few exceptions, the results were similar. Additional studies of this kind among different populations, and among mild dementia patients, are needed to cross-validate the results.

Activities of Daily Living↗

PubMed1994

Epidemiology of vascular and Alzheimer's dementia among African Americans in Chicago, IL: baseline frequency and comparison of risk factors.

We compared demographic, medical, and other epidemiologic factors among 113 African-American Alzheimer's disease (AD) patients and 79 African-American vascular dementia (VaD) patients. The typical background profile of our AD and VaD patients who entered into the study was that of women who were born and raised on farms in the southeastern United States, currently lived in an apartment or home in Chicago with other family members, and were retired, widowed, and had some form of medical insurance. The following distinct patient profiles emerged: (1) African-American AD patients were generally older than their VaD counterparts, more likely to have a family history of AD, Parkinson's disease and dementia, a history of head injury with loss of consciousness and hip fracture, and more severe cognitive impairment and difficulty with instrumental activities of daily living. (2) African-American VaD patients had a higher frequency of cardiovascular disease risk factors and focal neurologic findings, more difficulty with activities of daily living, and a higher frequency of medication use. Differences in risk-factor profile may help explain differential susceptibility by dementia subtype. Since ethnic minorities will constitute a higher proportion of the United States population in the future, targeted epidemiologic research to better understand etiology and risk factors for the dementias of middle and later life among minorities is needed.

Black or African American↗

PubMed1994

Psychiatric symptoms in dementia associated with stroke: a case-control analysis among predominantly African-American patients.

As part of a case-control study, the psychiatric symptoms and behavioral problems of 61 multi-infarct dementia (MID) cases and 86 multi-infarct controls without dementia were compared to determine the prevalence of psychiatric symptoms and to clarify psychiatric predictors of dementia associated with cerebral infarcts. Ninety-two percent of the cases and 85% of the controls were African American. Cases were generally older, less well educated, and had a greater number of strokes and more neurologic deficits than controls. The most frequent psychiatric symptoms as reported by caregivers of patients with MID were irritability (57.3%), apathy (44.4%), insomnia (43.6%), agitation (40.7%), impatience (37%), and emotional lability (28.3%). In multivariate analysis, apathy and irritability were independent predictors of dementia associated with cerebral infarcts unless tests of cognitive function were added to the model. Our findings suggest that psychiatric symptoms are common in African-American vascular dementia patients, and cognitive impairment may be associated with psychiatric symptoms, behavioral problems, and personality changes. As there is a paucity of information about the prevalence of psychiatric symptoms in African Americans with vascular dementia, additional studies are needed to validate these findings. A better understanding of psychiatric symptoms in vascular dementia could lead to improved diagnosis and treatment of this disorder.

Black or African American↗

PubMed1993

Risk factors for dementia associated with multiple cerebral infarcts. A case-control analysis in predominantly African-American hospital-based patients.

OBJECTIVE: To clarify risk factors for dementia associated with cerebral infarction. DESIGN: Case-control study. SETTING: The study was conducted in a hospital setting. PATIENTS: The subjects were consecutive patients with acute stroke with multiple cerebral infarctions who were admitted to the hospital between November 1, 1987, and December 1, 1990. They were predominantly elderly African Americans. Index cases met criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, for multi-infarct dementia, whereas control subjects were patients with multiple infarcts who did not have dementia. There were 61 multi-infarct disease index cases and 86 controls without cognitive impairment. MAIN OUTCOME MEASURES: Demographic and cardiovascular disease risk factor variables. RESULTS: Index cases were older (mean [+/- SD] age, 75.5 +/- 9.7 vs 69.6 +/- 9.1 years), were less well educated (odds ratio, 4.37; confidence interval, 2.12 to 9.04), had lower annual incomes (odds ratio, 8.82; confidence interval, 2.38 to 32.70), more frequently had a family history of dementia (odds ratio, 3.61; confidence interval, 1.09 to 11.96) and laboratory evidence of proteinuria (odds ratio, 3.66; confidence interval, 1.54 to 8.71), had lower scores on neuropsychological tests, had more neurologic signs and symptoms, and were more functionally impaired in activities of daily living. Multiple logistic regression analysis showed that advanced age, lower educational attainment, history of myocardial infarction, and recent cigarette smoking were positively associated with case status and systolic blood pressure level was negatively associated with case status. CONCLUSIONS: Cardiovascular disease risk factors may be modifiable predictors of dementia associated with cerebral infarction. Additional well-designed epidemiologic studies are needed to clarify these associations.

Black or African American↗