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Biomedical subjects

L M Sullivan

Publications and source records attributed to L M Sullivan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Tutorial in biostatistics. An introduction to hierarchical linear modelling.

Hierarchical linear models are useful for understanding relationships in hierarchical data structures, such as patients within hospitals or physicians within hospitals. In this tutorial we provide an introduction to the technique in general terms, and then specify model notation and assumptions in detail. We describe estimation techniques and hypothesis testing procedures for the three types of parameters involved in hierarchical linear models: fixed effects, covariance components, and random effects. We illustrate the application using an example from the Type II Diabetes Patient Outcomes Research Team (PORT) study and use two popular PC-based statistical computing packages, HLM/2L and SAS Proc Mixed, to perform two-level hierarchical analysis. We compare output from the two packages applied to our example data as well as to simulated data. We elaborate on model interpretation and provide guidelines for model checking.

Adult↗
PubMed1999

Alcohol abuse and dependence in Latinos living in the United States: validation of the CAGE (4M) questions.

BACKGROUND: Brief alcoholism screening questionnaires have not been adequately studied in the rapidly growing Latino population living in the United States. OBJECTIVE: To assess (1) the prevalence of alcoholism and (2) the performance of 2 alcohol screening instruments in Latinos. SUBJECTS AND METHODS: We performed a cross-sectional interview study in an urban teaching hospital-based primary care practice. Consecutive self-identified Latino subjects provided informed consent. All subjects were interviewed in English or Spanish using 2 alcoholism screening tools, the CAGE (or the Spanish version, the 4M), and the Alcohol Use Disorders Identification Test, and a criterion standard for the diagnosis of alcohol abuse and dependence, the Composite International Diagnostic Interview. RESULTS: Of 210 subjects interviewed, 36% had a lifetime diagnosis of alcohol abuse or dependence by the criterion standard. Thirty-one percent were currently drinking hazardous amounts of alcohol. A CAGE (4M) score of 1 or more was 92% sensitive and 74% specific, and a score of 2 or more was 80% sensitive and 93% specific for a lifetime diagnosis of alcohol abuse or dependency. CAGE (4M) scores of 0, 2, 3, and 4 were associated with likelihood ratios (0.1, 4.8, 18.5, and 36.8, respectively) that resulted in substantial changes from pretest (36%) to posttest probability (to 6%, 73%, 91%, and 95%, respectively) of a diagnosis of alcohol abuse or dependency. At the standard cutoff point, the Alcohol Use Disorders Identification Test detected only 51% of subjects with alcohol disorders. CONCLUSIONS: In Latinos in primary care settings, alcohol abuse and dependence are common and the CAGE (4M) is a brief, valid, screening tool for detecting alcohol use disorders.

Adult↗
PubMed1999

Prevalence of depressive and alcohol abuse symptoms among women VA outpatients who report experiencing sexual assault while in the military.

Among a national sample of 3,632 women VA outpatients, we determined self-reported prevalence of sexual assault experienced during military service and compared screening prevalence for current symptoms of depression and alcohol abuse between those who did and did not report this history. Data were obtained by mailed questionnaire. Military-related sexual assault was reported by 23%. Screening prevalence for symptoms of current depression was 3 times higher and for current alcohol abuse was 2 times higher among those who reported experiencing military-related sexual assault. Recent mental health treatment was reported by 50% of those who reported experiencing sexual assault during military service and screened positive for symptoms of depression, and by 40% of those who screened positive for symptoms of alcohol abuse.

Adult↗
PubMed1999

Cognitive changes following recovery from depression in a group cognitive-behaviour therapy program.

OBJECTIVE: We report on the changes in cognitions as a result of cognitive-behaviour therapy (CBT), in 35 recovered and 32 non-recovered mood disordered patients who had undergone a 12-week group CBT program for depression. METHOD: An end-of-therapy cut-off score of 10 on the BDI was used to define recovered and non-recovered patients. ANOVA analyses were conducted to explore possible main effects of recovery status and time on various clinical measures, including cognitions and activity levels. RESULTS: Mean mood and activity self-rating measures were significantly higher for the recovered as compared to the non-recovered patients over the course of the program. Similarly, scores on the Automatic Thoughts Questionnaire (ATQ) for recovered patients were within the non-clinical range, in contrast to their non-recovered counterparts. In addition, recovered patients improved significantly in their Hopelessness scores, and there was a change in the expected direction in their Dysfunctional Attitudes Scale scores, although this was not significant. CONCLUSION: These results are consistent with the proposition of cognitive theory (i.e. the remediation of negative cognition plays a significant role in recovery from depression during CBT).

Adult↗
PubMed1999

Dietary fat, body weight, and cancer: contributions of studies in rodents to understanding these cancer risk factors in humans.

Understanding diet and energy balance as risk factors for breast, colon, and other cancers requires information on the contribution of each factor and of interactions among factors to cancer risk. Rodent models for breast cancer provide extensive data on effects of dietary fat and calories, energy balance, body weight gain, and physical activity on tumor development. Analyses of the combined data from many studies have shown clearly that quality and quantity of dietary fat and energy balance contribute independently to increased mammary gland tumorigenesis. These findings were seen in female rats fed diets high in fat (35-40% of calories) compared to rats fed control diets, with approximately 10% of calories as fat (Fay and Freedman, 1997, Breast Cancer Res. Treat. 46, 215-223). The methods used permit comparison of experimental and epidemiological data, and they may be useful in extrapolating between species and developing public health recommendations. In addition to the contributions of lifetime-diet composition, intake, energy balance, and physical activity to cancer risk, there are questions about the timing and duration of alterations in these factors and about the "dose-response" characteristics of cancer risk to the factors. Endocrine mechanisms may be significant in mammary gland tumor risk, but experimental and epidemiological data indicate that cancers at other sites, such as colon and liver, also are influenced by the factors listed. Other diet and lifestyle factors that influence energy, or specifically fat, metabolism may also affect risk for cancers that are promoted by increased intake of fat and calories. Studies of separate and interactive effects of dietary fat, black tea, weight gain, and mammary gland tumorigenesis (Rogers, et al, 1998, Carcinogenesis 19, 1269-1273) have been analyzed. Using adjustment of carcinogenesis endpoints for body weight, tumor burden, and latency, they were found to be related to weight gain within treatment groups in 2 of 3 experiments.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1999

Synergistic inhibition of lysophosphatidic acid signaling by charged and uncharged local anesthetics.

UNLABELLED: We investigated the mechanism of benzocaine (permanently uncharged) and QX314 (permanently charged) inhibition of lysophosphatidic acid (LPA) signaling. To determine their site of action, we studied effects of these drugs, alone and in combination, on LPA-induced Ca2+-dependent Cl currents (I(Cl(Ca))) in Xenopus oocytes. After 10 min exposure to benzocaine, QX314 (10(-6)-10(-2) M), or both, we measured effects on I(Cl(Ca)) induced by LPA (with and without protein kinase [PKC] activation/inhibition) and on I(Cl(Ca)) induced by the intracellular injection of IP3 and GTPgammaS. LPA application to oocytes resulted in I(Cl(Ca)) (50% effective concentration approximately 10(-8) M). Both anesthetics inhibited LPA signaling concentration-dependently (50% inhibitory concentration [IC50] benzocaine 0.9 mM, QX314 0.66 mM). The combination acted synergistically (IC50 benzocaine 0.097 mM/QX314 0.048 mM). Intracellular signaling pathways were not affected. This study shows that benzocaine and QX314 inhibit LPA signaling and act synergistically, which is most easily explained by the existence of two different binding sites. Lack of inhibition of IP3 or GTPgammaS-induced I(Cl(Ca)) identifies the receptor as a target. Activation of PKC can be excluded as a potential mechanism. IMPLICATIONS: Lysophosphatidic acid may play a role in wound healing, and its signaling is inhibited by local anesthetics. We identified the membrane receptor as the local anesthetic site of action and showed that charged (QX314) and uncharged (benzocaine) local anesthetics inhibit lysophosphatidic acid signaling synergistically, which can be explained by the presence of different binding sites.

Anesthetics, Local↗
PubMed1999

Comparing the health status of male and female veterans who use VA health care: results from the VA Women's Health Project.

BACKGROUND: In recent years the number of women serving in the military has increased substantially, resulting in more demand for VA services by women veterans. This paper describes the characteristics and health status of women veterans who use VA ambulatory services. METHODS: Respondents in the VA Women's Health Project (n = 719) represent a randomly selected subsample from all women who had an ambulatory visit between July 1, 1994 and June 30, 1995 at a large tertiary care VA facility in the Boston area. Summary statistics on eight dimensions of health status (using the SF-36) for women veterans who use VA ambulatory care are provided. Comparisons are made between women veterans and men veterans who use VA services. RESULTS: Women veterans reported consistently low scores on health status across multiple dimensions, reflecting considerable health needs. Among veterans using VA services, women were younger, better educated, and less likely to be married than male veterans. Women veterans who use VA ambulatory services scored lower on every scale except physical functioning and general health perceptions when compared to male VA users. There were more pronounced differences for women on scales measuring emotional health. CONCLUSIONS: Health status among women veterans is moderate to poor. Important differences in health status are observed between men and women who use VA services which have implications for improving health care to women veterans at VA facilities. These findings strongly indicate that increased mental health services need to be available for women veterans seeking VA health care.

Confounding Factors, Epidemiologic↗
PubMed1998

Breast cancer care in older women: sources of information, social support, and emotional health outcomes.

BACKGROUND: The authors studied older women with breast cancer and asked: 1) where do older women get information regarding breast cancer care and how helpful do they perceive each of these sources to be? and 2) what aspects of social support are associated with older women's general and breast cancer specific emotional health outcomes? METHODS: To be eligible, women had to be at least 55 years of age and newly diagnosed with TNM Stage I or II breast cancer. Data were collected from women's surgical records and a 35-minute, computer-assisted telephone interview. RESULTS: Nearly all women rated information that was provided by their breast cancer physicians as very or somewhat helpful. Written materials provided by breast cancer physicians also were frequently rated as very or somewhat helpful. Women's marital status, religious service attendance, ratings of their physicians' technical and interpersonal care, and perceptions of their own abilities to communicate with their physicians were significantly associated with both general and breast cancer specific emotional health outcomes (all P < 0.05). CONCLUSIONS: Although older women obtained information regarding breast cancer from a variety of sources, they relied heavily on their physicians for information. To care most effectively for this group of patients, an increased understanding of the relation between the processes and outcomes of breast cancer care is needed Identifying older women with breast cancer at risk for poor emotional health outcomes and developing methods to enhance physician-patient communication in this setting may improve these outcomes.

Aged↗
PubMed1998

Costs and outcomes of AIDS care: comparing a health maintenance organization with fee-for-service systems in the Boston Health Study.

OBJECTIVE: A 4-month observational cohort study was performed to compare the performance of one health maintenance organization (HMO) with two fee-for-service (FFS) systems in Boston, Massachusetts in treating 255 patients with AIDS. MAIN OUTCOME MEASURES: Total 4-month costs; cost subcomponents, including inpatient, outpatient, home care, and zidovudine costs; functional status (difficulties with activities of daily living); and satisfaction with care. RESULTS: Compared with FFS patients, HMO patients were better educated, more often white, less often on Medicaid, and more often reported homosexual or bisexual behaviors as HIV risk factors (all factors, p = .001). Both groups had similar duration of AIDS, baseline hemoglobin levels, and leukocyte counts. Total 4-month costs at the HMO were significantly lower than those in the FFS settings ($4799 U.S. versus $8540 U.S.; p = .013), as were outpatient costs ($1131 U.S. versus $1614 U.S.; p = .001), after adjustment for sociodemographic factors, baseline functioning, main HIV risk factor, and other clinical variables. Adjusted physical functioning (p = .32) and patient satisfaction (p = .82). were similar between systems. CONCLUSIONS: The HMO had significantly lower total costs without any observable decrement in functional outcomes or patient satisfaction. The largest component of these cost savings came from reduced spending on inpatient care, but the HMO also spent less on outpatient and home care. Better coordination of care at the HMO may have been responsible for these lower costs.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Sexual ethics. Disclosure of HIV-positive status to partners.

OBJECTIVE: To determine factors associated with disclosure of human immunodeficiency virus (HIV)-positive status to sexual partners. METHODS: We interviewed 203 consecutive patients presenting for primary care for HIV at 2 urban hospitals. One hundred twenty-nine reported having sexual partners during the previous 6 months. The primary outcome of interest was whether patients had told all the sexual partners they had been with over the past 6 months that they were HIV positive. We analyzed the relationships between sociodemographic, alcohol and drug use, social support, sexual practice, and clinical variables; and whether patients had told their partners that they were HIV positive was analyzed by using multiple logistic regression. RESULTS: Study patients were black (46%), Latino (23%), white (27%), and the majority were men (69%). Regarding risk of transmission, 41% were injection drug users, 20% were homosexual or bisexual men, and 39% were heterosexually infected. Sixty percent had disclosed their HIV status to all sexual partners. Of the 40% who had not disclosed, half had not disclosed to their one and only partner. Among patients who did not disclose, 57% used condoms less than all the time. In multiple logistic regression analysis, the odds that an individual with 1 sexual partner disclosed was 3.2 times the odds that a person with multiple sexual partners disclosed. The odds that an individual with high spousal support disclosed was 2.8 times the odds of individuals without high support, and the odds that whites or Latinos disclosed was 3.1 times the odds that blacks disclosed. CONCLUSIONS: Many HIV-infected individuals do not disclose their status to sexual partners. Nondisclosers are not more likely to regularly use condoms than disclosers. Sexual partners of HIV-infected persons continue to be at risk for HIV transmission.

Disclosure↗
PubMed1998

Distinguishing hantavirus pulmonary syndrome from acute respiratory distress syndrome by chest radiography: are there different radiographic manifestations of increased alveolar permeability?

Hantavirus infection may cause diffuse air space disease, termed hantavirus pulmonary syndrome (HPS). The authors sought to determine if chest radiographs could differentiate HPS from typical acute respiratory distress syndrome (ARDS). The authors identified patients with either HPS (n = 11) or acute ARDS (n = 32) and selected the earliest chest radiograph showing diffuse airspace disease, and a chest radiograph taken 24 to 48 hours previously. Thoracic and general radiologists first viewed the chest radiograph showing diffuse air space disease, and ranked the likelihood that each case represented HPS versus ARDS. Afterward, readers viewed earlier chest radiographs and rescored each case. Receiver operating characteristic (ROC) curves from both scoring sessions were generated. The mean areas under the ROC curves for the entire group was 0.83 +/- 0.12 initially, and improved to 0.87 +/- 0.09 (p < 0.05) after viewing prior chest radiographs. Receiver operating characteristic curves of thoracic radiologists described greater areas than those of general radiologists both before and after viewing prior chest radiographs; 0.95 +/- 0.01 versus 0.78 +/- 0.08 (p < 0.05) and 96 +/- 0.02 versus 0.80 +/- 0.05 (p < 0.05). The mean sensitivity and specificity of chest radiograph interpretation for HPS was 86 +/- 13% and 74 +/- 11%, respectively. Chest radiographs can differentiate HPS from ARDS. Accuracy is improved by the use of serial radiographs and more highly trained readers. The chest radiograph findings may represent differences in the extent of alveolar epithelial damage seen in HPS and ARDS.

Acute Disease↗
PubMed1997

Bronchoesophageal fistula in an 11-month-old boy.

We report a case of a rare type of bronchoesophageal fistula that communicated with the patient's normal bronchial tree, but had systemic arterial supply. Although included within the spectrum of bronchopulmonary foregut malformations, only three other similar cases have been reported in the literature. At the time of presentation, the 11-month-old male patient was afebrile with coarse breath sounds at the left lung base. A barium swallow demonstrated the connection between the distal esophagus and a left lower lobe bronchus. CT also helped to delineate the course of the fistula.

Barium Sulfate↗
PubMed1997

Metabolic control and prevalent cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM): The NIDDM Patient Outcome Research Team.

PURPOSE: Cardiovascular disease is a major cause of morbidity and death in non-insulin-dependent diabetes mellitus (NIDDM). While hyperglycemia is clearly related to diabetic microvascular complications, it contribution to large-vessel atherosclerosis is controversial. PATIENTS AND METHODS: We performed an analysis of the association between glycemic control and prevalent cardiovascular disease in 1,539 participants in the NIDDM Patient Outcomes Research Team study who were under usual care in a health maintenance organization. Prevalent cardiovascular disease and its risk factors were identified by self-administered questionnaire. Cardiovascular disease was defined by the presence of coronary heart disease, peripheral vascular disease, and/or cerebrovascular disease. Glycohemoglobin and lipid levels were obtained from a computerized laboratory database. RESULTS: The mean age of participants was 63 years (range 31 to 91); 51% were women. The mean duration of NIDDM was 9 years (range < 1 to 50), 35% took insulin, and 48% took sulfonylureas. Mean glycohemoglobin was 10.6%. Sixty percent had hypertension, 16% currently smoked cigarettes, and the mean total high-density lipoprotein (HDL) cholesterol ratio was 5.7. Fifty-one percent had cardiovascular disease. Cardiovascular disease prevalence remained constant across increasing quartiles of glycohemoglobin for both men and women. In contrast, prevalent cardiovascular disease was associated with established cardiovascular disease risk factors including age (67 versus 59 years, P < 0.0001), hypertension (66% versus 54%, P < 0.0001), current cigarette smoking (17% versus 13%, P < 0.005), and total/HDL cholesterol ratio (5.9 versus 5.6, P < 0.005). Cardiovascular disease was also associated with duration of NIDDM (11 versus 8 years, P < 0.0001). In multiple logistic regression analysis controlling for established cardiovascular disease risk factors and diabetes duration and therapy, glycohemoglobin remained unassociated with cardiovascular disease. CONCLUSIONS: Glycemic control is not associated with prevalent cardiovascular disease in this large population of individuals with NIDDM. Conventional cardiovascular disease risk factors are independently associated with cardiovascular disease and be a more promising focus for clinical intervention to reduce atherosclerotic complications in NIDDM.

Adult↗
PubMed1997

PCR quantitation of fetal cells in maternal blood in normal and aneuploid pregnancies.

Fetal cells in maternal blood are a noninvasive source of fetal genetic material for prenatal diagnosis. We determined the number of fetal-cell DNA equivalents present in maternal whole-blood samples to deduce whether this number is affected by fetal karyotype. Peripheral blood samples were obtained from 199 women carrying chromosomally normal fetuses and from 31 women with male aneuploid fetuses. Male fetal-cell DNA-equivalent quantitation was determined by PCR amplification of a Y chromosome-specific sequence and was compared with PCR product amplified from known concentrations of male DNA run simultaneously. The mean number of male fetal-cell DNA equivalents detected in 16-ml blood samples from 90 women bearing a 46,XY fetus was 19 (range 0-91). The mean number of male fetal-cell DNA equivalents detected in 109 women bearing a 46,XX fetus was 2 (range 0-24). The mean number of male fetal-cell DNA equivalents detected when the fetus was male compared with when the fetus was female was highly significant (P = .0001). More fetal cells were detected in maternal blood when the fetus was aneuploid. The mean number of male fetal-cell DNA equivalents detected when the fetal karyotype was 47,XY,+21 was 110 (range 0.1-650), which was significantly higher than the number of male fetal-cell DNA equivalents detected in 46,XY fetuses (P = .0001). Feto-maternal transfusion of nucleated cells appears to be influenced by fetal karyotype. The sixfold elevation of fetal cells observed in maternal blood when the fetus had trisomy 21 indicates that noninvasive cytogenetic diagnosis of trisomy 21 should be feasible.

Aneuploidy↗
PubMed1996

Sex differences in academic advancement. Results of a national study of pediatricians.

BACKGROUND: Although the numbers of women in training and in entry-level academic positions in medicine have increased substantially in recent years, the proportion of women in senior faculty positions has not changed. We conducted a study to determine the contributions of background and training, academic productivity, distribution of work time, institutional support, career attitudes, and family responsibilities to sex differences in academic rank and salary among faculty members of academic pediatric departments. METHODS: We conducted a cross-sectional survey of all salaried physicians in 126 academic departments of pediatrics in the United States in January 1992. Of the 6441 questionnaires distributed, 4285 (67 percent) were returned. The sample was representative of U.S. pediatric faculty members. Multivariate models were used to relate academic rank and salary to 16 independent variables. RESULTS: Significantly fewer women than men achieved the rank of associate professor or higher. For both men and women, higher salaries and ranks were related to greater academic productivity (more publications and grants), more hours worked, more institutional support of research, greater overall career satisfaction, and fewer career problems. Less time spent in teaching and patient care was related to greater academic productivity for both sexes. Women in the low ranks were less academically productive and spent significantly more time in teaching and patient care than men in those ranks. Adjustment for all independent variables eliminated sex differences in academic rank but not in salary. CONCLUSIONS: Lower rates of academic productivity, more time spent in teaching and patient care and less time spent in research, less institutional support for research, and lower rates of specialization in highly paid subspecialties contributed to the lower ranks and salaries of female faculty members.

Academic Medical Centers↗
PubMed1996

Robustness and power of analysis of covariance applied to data distorted from normality by floor effects: homogeneous regression slopes.

We investigate through computer simulations the robustness and power of two group analysis of covariance test applied to small samples distorted normality by floor effects when the regression slopes are homogeneous. We consider four parametric analysis of covariance tests that vary according to the treatment of the homogeneity of regression slopes and two t-tests on unadjusted means and on difference scores. Under the null hypothesis of no difference in means, we estimated actual significance levels by comparing observed test statistics to appropriate values from the F and t distributions for nominal significance levels of 0.10, 0.05, 0.02 and 0.01. We estimated power by similar comparisons under various alternative hypothesis. The hierarchical approach (that adjusts for non-homogeneous slopes if found significant), the test that assumes homogeneous regression slopes, and the test that estimates separate regression slopes in each treatment were robust. In general, each test produced power at least equal to that expected from normal theory. The textbook approach, which does not test for mean differences when there is significant non-homogeneity, was conservative but also had good power. The t-tests were robust but had poorer power properties than the above procedures.

Analysis of Variance↗