Biomedical subjects

K Vranizan

Publications and source records attributed to K Vranizan.

At least 37 records · Page 2Linked to original sources

PubMed1996

The role of black and Hispanic physicians in providing health care for underserved populations.

BACKGROUND: Patients who are members of minority groups may be more likely than others to consult physicians of the same race or ethnic group, but little is known about the relation between patients' race or ethnic group and the supply of physicians or the likelihood that minority-group physicians will care for poor or black and Hispanic patients. METHODS: We analyzed data on physicians' practice locations and the racial and ethnic makeup and socioeconomic status of communities in California in 1990. We also surveyed 718 primary care physicians from 51 California communities in 1993 to examine the relation between the physicians' race or ethnic group and the characteristics of the patients they served. RESULTS: Communities with high proportions of black and Hispanic residents were four times as likely as others to have a shortage of physicians, regardless of community income. Black physicians practiced in areas where the percentage of black residents was nearly five times as high, on average, as in areas where other physicians practiced. Hispanic physicians practiced in areas where the percentage of Hispanic residents was twice as high as in areas where other physicians practiced. After we controlled for the racial and ethnic makeup of the community, black physicians cared for significantly more black patients (absolute difference, 25 percentage points; P < 0.001) and Hispanic physicians for significantly more Hispanic patients (absolute difference, 21 percentage points; P < 0.001) than did other physicians. Black physicians cared for more patients covered by Medicaid (P = 0.001) and Hispanic physicians for more uninsured patients (P = 0.03) than did other physicians. CONCLUSIONS: Black and Hispanic physicians have a unique and important role in caring for poor, black, and Hispanic patients in California. Dismantling affirmative-action programs as is currently proposed, may threaten health care for both poor people and members of minority groups.

Black or African American↗

PubMed1996

Primary care and receipt of preventive services.

OBJECTIVE: To examine whether health insurance, a regular place of care, and optimal primary care are independently associated with receiving preventive care services. DESIGN: A cross-sectional telephone survey. SETTING: Population based. PARTICIPANTS: Probability sample of 3,846 English-speaking and Spanish-speaking women between the ages of 18 and 64 in urban California. INTERVENTIONS: Women were asked about their demographic characteristics, financial status, health insurance status, need for ongoing care, regular place of care, and receipt of blood pressure screening, clinical breast examinations, mammograms, and Pap smears. Women who reported a regular place of care were asked about four components of primary care: availability, continuity, comprehensiveness, and communication. MEASUREMENTS AND MAIN RESULTS: In multivariate analyses that controlled for differences in demographics, financial status, and need for ongoing care, having a regular place of care was the most important factor associated with receiving preventive care services (p < .0001). Having health insurance (p < .001) and receiving optimal primary care from the regular place of care (p < .01) further significantly increased the likelihood of receiving preventive care services. CONCLUSION: A regular source of care is the single most important factor associated with the receipt of preventive services, but optimal primary care from a regular place increases the likelihood that women will receive preventive care.

Adolescent↗

PubMed1996

Physician practice style and rates of hospitalization for chronic medical conditions.

Hospitalization rates for chronic medical conditions vary across small areas and are associated inversely with community income. The authors studied whether variation in hospitalization rates can be attributed to differences in physician practice style. Using census and hospital discharge data, hospitalization rates were calculated for asthma, congestive heart failure, and diabetes in 40 medical service areas in California. The authors surveyed a random sample of 1,530 emergency physicians, general internists, and family and general practitioners in these areas, and measured clinical admission threshold by asking physicians whether they would hospitalize patients presented in 15 vignettes of graded severity. The authors measured social admission predisposition by asking how physicians' admission decisions would be influenced by social characteristics that increase patients' vulnerability to illness, including homelessness and drug use; 1,090 physicians responded (71%). There was significant variation across areas in both the clinical (P < 0.0001) and social (P < 0.001) admission scores. Variation in hospitalization rates correlated with physicians' clinical (r = .34, P = 0.03) and social (r = .36, P = 0.02) admission scores. However, in a multiple linear regression analysis that included community sociodemographic factors, physician practice style was not associated significantly with hospitalization rates. Physician practice style varies across areas, but does not explain variation in admission rates for chronic medical conditions after adjusting for community sociodemographic factors. Using methods such as practice guidelines or utilization review to re-set physicians' threshold for admission may not be effective in reducing hospitalizations for chronic medical conditions.

Adult↗

PubMed1996

Measuring the need for medical care in an ethnically diverse population.

OBJECTIVE: To examine measures of need for health care and their relationship to utilization of health services in different racial and ethnic groups in California. DATA SOURCE: Telephone interviews obtained by random-digit dialing and conducted between April 1993 and July 1993 in California, with 7,264 adults (ages 18-64): 601 African Americans, 246 Asians, 917 Latinos interviewed in English; 1,045 Latinos interviewed in Spanish; and 4,437 non-Latino whites. STUDY DESIGN: A cross-sectional survey was conducted from a stratified, probability telephone sample. DATA COLLECTION: Interviews collected self-reported indicators of need for health care: self-rated health, activity limitation, major chronic conditions, need for ongoing treatment, bed days, and prescription medication. The outcome was self-reported number of physician visits in the previous three months. PRINCIPAL FINDINGS: Compared to whites, one or more of the other ethnic groups varied significantly (p < .05) on each of the six need-for-care measures after adjustment for health insurance, age, sex, and income. Latinos interviewed in Spanish reported lower percentages and means on five of the need measures but the highest percentage with fair or poor health (32 percent versus 7 percent in whites). Models regressing each need measure on the number of outpatient visits found significant interactions of ethnic group with need compared to whites. After adjustment for insurance and demographics, the estimated mean number of visits in those with the indicator of need was consistently lower in Latinos interviewed in Spanish, but the differences among the other ethnic groups varied depending on the measure used. CONCLUSION: No single valid estimate of the relationship between need for health care and outpatient visits was found for any of the six indicators across ethnic groups. Applying need adjustment to the use of health care services without regard for ethnic variability may lead to biased conclusions about utilization.

Adolescent↗

PubMed1995

Graduate medical education and physician practice location. Implications for physician workforce policy.

OBJECTIVE: To determine the relationship between graduate medical education and physician practice location. DESIGN: Cross-sectional analysis of physicians in active practice in 1993, classified by state of graduate medical education and stratified by specialty and professional activity. Logistic regression analysis was used to examine predictors of physicians remaining to practice in the same state in which they trained. SETTING: There were 82,871 allopathic physicians (national random sample) and 15,076 osteopathic physicians (universe) who completed graduate medical education between 1980 and 1992. MAIN OUTCOME MEASURE: Practice location in the same state as graduate medical education. RESULTS: Overall, 51% of physicians are practicing in the state in which they obtained their graduate medical education (range among states, 6% to 71%). Generalist physicians are more likely than specialists to remain in their state of graduate medical education (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.33 to 1.40) There is a weak negative association between the number of physicians in training per capita in a state and the likelihood of a physician remaining in the state to practice (OR, 0.90; 95% CI, 0.90 to 0.91, for an increment in resident supply of 10 per 100,000 population). New York and Massachusetts, the states with the highest numbers of residents per capita, retained 51% and 49%, respectively, of their graduates, placing them near the median among states. CONCLUSIONS: Most physician training and practice locations function as a national market, with physicians dispersing relatively widely after completing graduate medical education. States that produce high numbers of physicians per capita do not appear to play a unique role in training physicians to serve a national market. These findings pose challenges for states attempting to modify their physician supply and specialty mix.

Cross-Sectional Studies↗

PubMed1995

Preventable hospitalizations and access to health care.

OBJECTIVE: To examine whether the higher hospital admission rates for chronic medical conditions such as asthma, hypertension, congestive heart failure, chronic obstructive pulmonary disease, and diabetes in low-income communities resulted from community differences in access to care, prevalence of the diseases, propensity to seek care, or physician admitting style. DESIGN: Analysis of California hospital discharge data. We calculated the hospitalization rates for these five chronic conditions for the 250 ZIP code clusters that define urban California. We performed a random-digit telephone survey among adults residing in a random sample of 41 of these urban ZIP code clusters stratified by admission rates and a mailed survey of generalist and emergency physicians who practiced in the same 41 areas. SETTING: Community based. PARTICIPANTS: A total of 6674 English- and Spanish-speaking adults aged 18 through 64 years residing in the 41 areas were asked about their access to care, their chronic medical conditions, and their propensity to seek health care. Physician admitting style was measured with written clinical vignettes among 723 generalist and emergency physicians practicing in the same communities. MAIN OUTCOME MEASURES: We compared respondents' reports of access to medical care in an area with the area's cumulative admission rate for these five chronic conditions. We then tested whether access to medical care remained independently associated with preventable hospitalization rates after controlling for the prevalence of the conditions, health care seeking, and physician practice style. RESULTS: Access to care was inversely associated with the hospitalization rates for the five chronic medical conditions (R2 = 0.50; P < .001). In a multivariate analysis that included a measure of access, the prevalence of conditions, health care seeking, and physician practice style to predict cumulative hospitalization rates for chronic medical conditions, both self-rated access to care (P < .002) and the prevalence of the conditions (P < .03) remained independent predictors. CONCLUSION: Communities where people perceive poor access to medical care have higher rates of hospitalization for chronic diseases. Improving access to care is more likely than changing patients' propensity to seek health care or eliminating variation in physician practice style to reduce hospitalization rates for chronic conditions.

Adult↗

PubMed1994

HIV seroconversion in intravenous drug users in San Francisco, 1985-1990.

OBJECTIVE: To examine the HIV seroconversion rate, risk factors for seroconversion, and changes in risk behavior over time in intravenous drug users (IVDU) in San Francisco, 1985-1990. DESIGN: Observational study. SETTING: All methadone maintenance and 21-day methadone detoxification programs in San Francisco. PARTICIPANTS: A total of 2351 heterosexual IVDU, of whom 681 were seronegative at first visit and seen at least twice ('repeaters'). MAIN OUTCOME MEASURES: HIV seroconversion rates, risk factors for seroconversion, and changes in behavior. RESULTS: The HIV seroconversion rate in repeaters was 1.9% per person-year (ppy) of follow-up [2.1% in women versus 1.7% in men (not significant); 4% in African Americans versus 1% in whites (P = 0.006); 3.9% ppy in the first third of the study, 1.2% in the second (P = 0.007), and 1.9% in the last (not significant)]. Risk factors for seroconversion were five or more sexual partners per year [hazard ratio (HR) = 2.6; P = 0.02], use of shooting gallery ever (HR = 2.9; P = 0.02), and less than 1 year (lifetime) in methadone maintenance (HR = 2.7; P = 0.02). Self-reported intravenous cocaine use fell from 33 to 15% over 5 years, shooting gallery use fell from 19 to 6%, and the proportion with five or more sexual partners fell from 25 to 10%. Bleach use rose to 75% of needle-sharers. CONCLUSIONS: The 1985-1990 HIV seroconversion rate in IVDU (1.9% ppy) was comparable to that in San Francisco cohorts of homosexual men (1.4% ppy). A decline in HIV seroconversion coincided with changes in risk behavior. Stable attendance of methadone maintenance was highly protective: the seroconversion rate in subjects with 1 year or more in methadone was 12% ppy.

Adult↗

PubMed1994

HIV-related oral manifestations in two cohorts of women in San Francisco.

The goals of this study were to compare the prevalence of oral lesions in women infected with human immunodeficiency virus (HIV) and HIV-negative women, and to determine the association of oral lesions with route of HIV transmission and with level of immunosuppression in infected women. As part of a prospective 4-year study, oral examinations and blood tests were performed, at 6-month intervals, on 176 HIV-infected women and on 117 HIV-negative women at risk for HIV infection. We evaluated participants for the following oral conditions: hairy leukoplakia, candidiasis, ulcers, warts, non-Hodgkin's lymphoma, Kaposi's sarcoma, and parotid enlargement. As previously reported in men, the prevalence of oral lesions was significantly higher among HIV-infected (22%) than HIV-negative women (3%) [odds ratio (OR) = 8.2; 95% confidence interval (CI) 2.8, 23.5], particularly candidiasis (14%) and hairy leukoplakia (10%). Among HIV-infected women with CD4 cell count nadir > or = 200 cells/microliters, the prevalence of hairy leukoplakia was higher among those infected heterosexually than among injection drug users (OR = 5.5; 95% CI: 1.5; 19). The OR for the association between oral lesions and CD4 cell count nadir (< 200 vs. > 500 cells/microliters) was 8.9 (95% CI: 2.6, 30), indicating a strong positive association with level of immunosuppression.

Adult↗

PubMed1994

Anal and cervical human papillomavirus infection and risk of anal and cervical epithelial abnormalities in human immunodeficiency virus-infected women.

OBJECTIVE: To determine the prevalence of anal and cervical infection with human papillomavirus (HPV) and cytologic abnormalities and to examine the relation among HPV infection, cytologic abnormalities, and human immunodeficiency virus (HIV) serostatus. METHODS: Anal and cervical Papanicolaou tests, HPV dot blot tests, and polymerase chain reaction (PCR) tests for HPV were performed concurrently in a cross-sectional study of 114 women enrolled in a community-based study of HIV infection. RESULTS: Cervical HPV infection was associated with HIV serostatus by both dot blot (odds ratio [OR] 4.2, 95% confidence interval [CI] 1-25) and PCR (OR 8.9, 95% CI 3.2-27). Anal HPV infection was twice as frequent as cervical and also was associated with HIV by dot blot (OR 2.5, 95% CI 0.9-7) and PCR (OR 2.6, 95% CI 1.03-6.8). Eleven percent (11 of 96) of cervical cytologies were abnormal and were associated with HIV (OR 6.1, 95% CI 1.2-60.5). Fourteen percent (15 of 109) of anal cytologies were abnormal and were associated with HIV (OR 3.4, 95% CI 0.9-15.5). Among HIV-seropositive women, epithelial abnormalities were associated with lower mean CD4+ cell counts when HPV DNA was detected by dot blot at either the cervix (P = .04) or anus (P = .009). Independent predictors for cervical epithelial abnormalities were HPV DNA positivity by dot blot (OR 32.1, 95% CI 2.9-353.9) and positive HIV serostatus with CD4+ cell count below 250 cells/mm3 (OR 126.8, 95% CI 7.5-2132.6). CONCLUSIONS: Human papillomavirus-associated epithelial abnormalities are associated with immune suppression among HIV-infected women. Anal HPV infection and disease is at least as common as cervical infection and disease among HIV-seropositive women.

Adult↗

PubMed1992

Charting the epidemic: the case study of HIV screening of injecting drug users in San Francisco, 1985-1990.

HIV screening for drug users in treatment began in San Francisco in 1985, and was followed by street screening, community outreach, bleach distribution and other intervention programs. The HIV seroconversion rate fell from 4.5% per year in 1985-86 to 1.7% per year in 1987-88 and has remained stable at about 2% per year since 1988. While this decline cannot be attributed to specific programs, the broad spectrum of interventions in San Francisco appears to be keeping the new infection rate low. Future programs should aim at reducing heterosexual HIV transmission, at intervening with multiply-diagnosed drug users, and at providing service to homeless and other very poor drug-using groups.

HIV Infections↗

PubMed1991

Human T cell lymphotropic virus types I and II in intravenous drug users in San Francisco: risk factors associated with seropositivity.

Serologic assays for human T cell lymphotropic virus types I and II (HTLV I/II) infection were done in 676 intravenous drug users (IVDUs) in San Francisco between 1985 and 1987: 150 in 1985, 44 in 1986, and 482 in 1987. All sera were tested by Western blot, ELISA, and p24 RIA. A total of 111 participants were seropositive in a minimum of two assays. Duration of intravenous heroin use was strongly associated with the risk of HTLV I/II seropositivity: greater than or equal to 21 years odds ratio, 6.1 (95% confidence interval [CI], 2.2-17.5), compared with less than 10 years of heroin use. Additional independent risk factors included black or Hispanic race, female sex, and the use of drugs in a shooting gallery. Coinfection of HTLV I/II and human immunodeficiency virus was less frequent than expected by chance (P less than .02). Longitudinal specimens were available in 154 participants. The age- and race-adjusted seroconversion rate was 3.4% (95% CI, 1.3-8.9) per person per year. Of the 349 homosexual men tested, none were HTLV I/II-seropositive.

Adult↗

PubMed1987

Intermediate-density lipoproteins and progression of coronary artery disease in hypercholesterolaemic men.

Lipoprotein mass concentrations were measured by analytical ultracentrifugation in a subset of 57 hypercholesterolaemic male participants in the National Heart, Lung, and Blood Institute Type II Coronary Intervention Study. 2-year changes in levels of intermediate-density lipoproteins (IDL) of flotation rate 12-20 were strongly predictive of progression of coronary artery disease at 5 years. Changes in serum mass concentrations of low-density lipoproteins (LDL; flotation rate 0-12), very-low-density lipoproteins (VLDL; flotation rate 20-400), high-density lipoproteins (HDL), and the HDL2 and HDL3 subfractions did not differ significantly between men with and without definite progression of coronary artery disease. The relation of IDL mass to disease progression remained significant (p less than 0.05) after adjustment for group assignment to cholestyramine treatment or placebo and was only slightly reduced (p less than or equal to 0.06) by adjustment for changes in LDL mass concentrations. Changes in IDL mass and ratios of HDL-cholesterol to total-cholesterol or LDL-cholesterol were inversely correlated and had a similar ability to predict progression. The findings are consistent with earlier evidence that IDL are directly involved in the development of coronary artery disease and suggest that ratios of HDL-cholesterol to total-cholesterol or LDL-cholesterol may be indicators of coronary disease risk partly owing to relations with IDL metabolism.

Adult↗

PubMed1985

Vinblastine therapy for Kaposi's sarcoma in the acquired immunodeficiency syndrome.

Single-agent intravenous vinblastine, 4 to 8 mg/week, was used to treat 38 patients with Kaposi's sarcoma related to the acquired immunodeficiency syndrome. The dose was titrated in relation to the total leukocyte count. Ten patients had an objective response, and 19 had stable disease during therapy. Apart from expected modest neutropenia, toxicity was minimal. A lower response rate was seen in patients with anemia, an elevated erythrocyte sedimentation rate, or any lymphoma-like B symptom. Opportunistic infections were common regardless of type of response but were commoner in patients who did not respond. Vinblastine used in low doses weekly is effective in treating Kaposi's sarcoma related to the acquired immunodeficiency syndrome and has minimal associated toxicities.

Acquired Immunodeficiency Syndrome↗

PubMed1984

Indirect measures of cigarette use: expired-air carbon monoxide versus plasma thiocyanate.

Indirect, biochemical measures of cigarette use are valuable in confirming smoking status in both cross-sectional and cessation studies. This study compares two such biochemical markers, expired-air carbon monoxide (CO) and plasma thiocyanate (SCN), in a representative population sample of 2,237 adults (ages 18-74) from the baseline survey of the Stanford Five City Project. CO and SCN are both significantly higher in self-reported smokers than in nonsmokers and correlate well with number of cigarettes smoked per day. CO appears to be more sensitive and specific than SCN in comparison to self-report, and CO misclassifies a significantly smaller number of nonsmokers, regular smokers, and light smokers (less than 9 cigarettes per day) than does SCN. Together, CO and SCN better classify smokers and nonsmokers than do either alone. Neither biochemical is a reliable indicator in irregular smokers (no cigarettes in past 48 hr). Despite its much shorter metabolic half-life, CO is a better indicator of cigarette use than is SCN in this cross-sectional study. CO is generally simpler and less expensive to measure than is SCN, and CO may be a preferable indirect measure of smoking status in some studies of smoking cessation.

Adolescent↗

PubMed1983

The association of blood pressure and dietary alcohol: differences by age, sex, and estrogen use.

This paper presents the results of an analysis of dietary alcohol use and blood pressure in representative population samples from four northern California cities surveyed in 1979-1980 as part of the Stanford Five City Project. The pooled samples included 883 men and 959 women aged 20-74 who were not taking blood pressure medications. Blood pressure was obtained while seated using a standard manometer. Alcohol was assessed by self-report of usual intake. In men, age-specific analysis revealed a positive association between dietary alcohol and both systolic (SBP) and diastolic blood pressure (DBP). The association was linear in men aged 20-34 and 50-74 and was stronger in the oldest men. Both linear and quadratic terms were significant for men aged 35-49. This association remained significant in a linear regression model that included age, relative weight, income, education, physical activity, cigarette use, and untimed urinary sodium/creatinine; for alcohol in ml/day in men aged 50-74, beta = 0.21, p = 0.0001, R2 = 0.32 for SBP; beta = 0.09, p = 0.0002, R2 = 0.18 for DBP. In women, alcohol use was significantly associated with blood pressure only in those above age 49 and was more striking in those not taking estrogens; this association was also independent of the same variables listed above for men (beta = 0.43, p = 0.0001, R2 = 0.23 for SBP; beta = 0.17, p = 0.001, R2 = 0.13 for DBP). Multiple logistic analyses with hypertension as a dichotomous dependent variable and including all subjects showed similar results. These results could be due to any one or more of the following hypotheses: 1) a biologic response to alcohol in older men and in older women that is different from the response in younger persons; 2) a delayed effect of alcohol use on blood pressure; 3) effects of a different pattern of alcohol use in the different age groups; or 4) the presence of some unmeasured confounding factor in the older age groups.

Adolescent↗

PubMed1982

The effects of running mileage and duration on plasma lipoprotein levels.

Eighty-one healthy, sedentary men aged 30 to 55 years were randomly assigned to supervised running (n = 48) or to sedentary control groups (n = 33) and followed up in a one-year trial. Measurements of plasma lipoproteins, fitness, and percent body fat were made at three-month intervals. Results and conclusions from this study are (1) that cross-sectional studies of lipoprotein concentrations in exercisers may be biased by a self-selection effect, since study participants with initially higher high-density lipoprotein cholesterol (HDL-C) and lower triglyceride concentrations were more easily persuaded to run more miles; (2) that plasma concentrations of HDL-C and low-density lipoprotein cholesterol (LDL-C) generally did not begin to change until a threshold exercise level (ten miles run per week) was maintained for at least nine months; and (3) that fitness increased and percent body fat decreased sooner and at lower exercise levels than required for HDL-C and LDL-C concentration changes.

Adipose Tissue↗

PubMedDate not supplied

Reliability of sexual histories in heterosexual couples.

BACKGROUND AND OBJECTIVES: Reliability of responses between partners was used as a surrogate to examine the validity of self-reported sexual histories in two samples with different risk and demographic profiles and different intensities of contact with study staff. STUDY DESIGN: Retrospective self-report data were compared between partners and between samples. RESULTS: Despite differences between the two groups, reliability of the sexual history data was comparable. CONCLUSIONS: Further study is needed to examine other methodologies for collecting sensitive data. Intensive contact and rapport building may not be necessary.

Adult↗

PubMedDate not supplied

Physician supply and access to care in urban communities.

This paper uses an analysis of survey data from urban Californians to determine whether patients' reports of access to care were associated with physician supply. On unadjusted analyses, higher levels of physician supply were associated with better access to care. However, this association was no longer apparent after adjusting for underlying population characteristics such as insurance status, income, and race/ethnicity. Poorer access to care in communities with lower physician supply appeared to be explained mainly by lack of health insurance and other population characteristics rather than by physician supply. We conclude that a more geographically equitable distribution of physicians in urban areas is unlikely to compensate for an inegalitarian system of health insurance.

California↗