Search PubMed⌕ Search

Biomedical subjects

R A Hiatt

Publications and source records attributed to R A Hiatt.

At least 55 records · Page 3Linked to original sources
PubMed1993

The increased risk of coronary heart disease associated with nephrotic syndrome.

Patients with nephrotic syndrome (NS) are believed to be at increased risk of atherosclerosis and coronary heart disease (CHD), although existing evidence for this association has not been persuasive. The risk of CHD among 142 persons with NS documented by protein-uria > or = 3.5 g daily was compared with that among 142 matched controls randomly selected from the membership of a large Northern California health plan. Controls were matched for sex, year of birth, and presence in the health plan when the referent case was diagnosed. No diabetics were included in this study. Mean follow-up for nonfatal CHD events was 5.6 years for NS subjects and 11.2 years for controls. Among the NS subjects myocardial infarction (MI) developed in 11, and there were 58 deaths, seven because of CHD. Among the controls, there were four MIs and 10 deaths, three because of CHD. In matched-pair analysis, there were 11 MIs among NS subjects and none among controls [P = 0.001, lower bound of 95% confidence interval for relative risk (CI), 2.8]. In an unmatched analysis adjusted for hypertension and smoking at diagnosis of NS, the relative risk of MI was 5.5 (95% CI 1.6 to 18.3) and the relative risk of coronary death was 2.8 (95% CI 0.7 to 11.3). Omitting data of NS subjects with minimal change disease and systemic lupus erythematosus yielded similar results. These data suggest that persons with NS are at increased risk of CHD.

Adolescent↗
PubMed1993

Surveillance bias and the excess risk of malignant melanoma among employees of the Lawrence Livermore National Laboratory.

To assess the role of surveillance bias in the observed three-fold excess of cutaneous malignant melanoma (CMM) at the Lawrence Livermore National Laboratory (LLNL) in California, we examined the thickness of CMMs among all 20 laboratory employees who were members of a large prepaid health plan and whose CMM was diagnosed from 1970 through 1984. For comparison, we reviewed slides of 36 other members of the same health plan matched (usually 2:1) to the laboratory case by age, sex, facility, and year of diagnosis. Three expert dermatopathologists read the slides using a multiheaded microscope to reach a consensus; they were blind to the laboratory employment status of the subjects. We found that from 1970 to 1976, before there was widespread publicity about the excess incidence of CMM at LLNL, lesion thickness was greater for non-LLNL employees (mean difference = 1.5 mm; 95% confidence interval 0.1-2.9). From 1977 through 1984, however, there was no appreciable difference [mean difference = -0.3 mm; 95% confidence limits (CL) = -1.4, 0.9]. Dropping the matching to adjust for histologic type of melanoma as well as gender, year, and age at diagnosis yielded substantially the same results. These data are compatible with an effect of surveillance bias up to around 1976, but in this health plan population, they do not support a role for surveillance bias in the continuing excess incidence observed since that time.

Bias↗
PubMed1992

Misconceptions about cancer among Latinos and Anglos.

OBJECTIVE: To collect information regarding knowledge about and attitudes toward cancer in a sample of adult health plan members, self-identified as Latino or Anglo. DESIGN: Cross-sectional survey. SETTING: Prepaid health plan. RESPONDENTS: A random sample of 844 Latinos (mean age, 50.5 years) and 510 Anglos (51.8 years) completed the interview. MAIN OUTCOME MEASURES AND RESULTS: Latinos were significantly more likely than Anglos to think that sugar substitutes (58% vs 42%), bruises from being hit (53% vs 34%), microwave ovens (47% vs 23%), eating pork (31% vs 11%), eating spicy foods (15% vs 8%), breast-feeding (14% vs 6%), and antibiotics (32% vs 12%) could cause cancer (P < .001 for each). Compared with Anglos, Latinos more often misidentified constant dizziness (39% vs 25%) and arthralgias (35% vs 20%) as being symptoms of cancer. A higher proportion of Latinos believed that having cancer is like getting a death sentence (46% vs 26%), that cancer is God's punishment (7% vs 2%), that there is very little one can do to prevent getting cancer (26% vs 18%), that it is uncomfortable to touch someone with cancer (13% vs 8%), and that they would rather not know if they had incurable cancer (35% vs 23%; P < .001 for each). Latino ethnicity was a significant predictor of these knowledge and attitude items in multivariate logistic regression models adjusted for sex, education, age, employment, marital status, county of residence, and self-perceived health status. CONCLUSIONS: We conclude that misconceptions about cancer are more prevalent among Latinos than Anglos and that selected attitudes about cancer among Latinos fit a cultural theme of fatalismo. These data can enable development of culturally appropriate cancer control interventions for Latinos.

Adult↗
PubMed1992

Risk of breast cancer after benign breast diseases. Variation by histologic type, degree of atypia, age at biopsy, and length of follow-up.

The issue of risk of breast cancer subsequent to benign breast diseases (BBD) remains controversial. To determine whether this risk varies by histologic type of BBD, degree of atypia (as measured by the Black-Chabon method), age at BBD biopsy, or length of follow-up, the authors followed 2,731 women in the San Francisco Bay Area for an average of 16 years after their first occurrence of biopsy-proven BBD between 1948 and 1973. The cohort's age-adjusted rate of breast cancer was 1.8 times that of the general population (95% confidence interval (CI) 1.6-2.2). Among the different histologic types of BBD, rates were greatest for intraductal papilloma (rate ratio (RR) = 3.9, 95% CI 2.0-7.4) and adenosis (RR = 2.5, 95% CI 1.2-4.9). Rates were also significantly elevated for fibrocystic BBD (RR = 1.5, 95% CI 1.1-1.9). Risk increased directly with degree of atypia, rising from a rate ratio of 1.8 among women with Black-Chabon scores of 1 and 2 (95% CI 1.5-2.2) to 7.2 among women with a Black-Chabon score of 5 (95% CI 1.8-28.9). Among women with the higher-risk types of BBD, rate ratios increased with age at BBD biopsy and decreased with increasing length of cancer-free follow-up. These findings are interpreted in the light of possible biases affecting this and other studies and recent advances in knowledge regarding neoplastic lesions and breast cell kinetics.

Adult↗
PubMed1992

Seroprevalence of HIV-type 1 in a northern California health plan population: an unlinked survey.

We conducted an unlinked seroprevalence survey for human immunodeficiency virus-type 1 (HIV-1) of 9821 persons who had a routine personal health appraisal examination in 1989 while members of the Kaiser Permanente Medical Care Program in northern California. An outside laboratory performed enzyme immunoassay (EIA) analyses, and the California Viral and Rickettsial Diseases Laboratory confirmed EIA-reactive samples by immunofluorescent assay and Western blot assay. Only 20 specimens (0.2%) were confirmed as positive, and 18 were from men. These data suggest that, at the time of this survey, HIV-1 infection was not widespread in the northern California population represented by this health plan membership.

Adolescent↗
PubMed1991

Case-control study of screening for prostatic cancer by digital rectal examinations.

Although commonly thought to be an effective method of screening for prostatic cancer, digital rectal examinations have yet to be shown by controlled study to help prevent advanced forms of this disease. 139 men with metastatic (stage D) prostatic cancer (cases) were compared with an equal number of matched men free of this condition (controls), with respect to rectal examinations recorded in the medical records up to, on average, 23 years before the cases' initial diagnosis of prostatic cancer. Cases and controls were members of a large health maintenance organisation in northern California. In the 10 years before initial diagnosis (excluding the last three months) the average number of examinations for routine screening (2.45 vs 2.52) or to evaluate intestinal or rectal symptoms (0.44 in both) were similar in cases and controls, respectively. After adjustment for racial differences, the relative risk of metastatic prostatic cancer for men with one or more screening rectal examinations compared with men with none was 0.9 with a 95% confidence interval of 0.5-1.7. Screening by routine digital rectal examination appears to have little if any effect in preventing metastatic prostatic cancer. If there is a small benefit, it will be difficult to demonstrate by conventional epidemiological study.

Adult↗
PubMed1991

Weight gain by gestational age in both black and white women delivered of normal-birth-weight and low-birth-weight infants.

Although adequate maternal weight gain during pregnancy is widely acknowledged as a desirable goal, a contemporary standard for weight gain over the entire period of gestation based on a low-risk U.S. population has not been available. Information about usual weight gain in early pregnancy was particularly lacking. In a study monitoring various aspects of prenatal care in women in a population-based case-control study of low birth weight, we collected information on weight gain at various gestational ages in the 281 women who had prenatal care and were delivered of infants at a prepaid health plan facility where standardized records were kept. In white women who were delivered of infants who weighed greater than or equal to 3000 gm, average weight gain was 5.3 pounds at 9 to 10 weeks' gestation, 10.5 pounds at 11 to 20 weeks, 24.2 pounds at 21 to 30 weeks, and 35.1 pounds at 31 to 40 weeks. Weight gain among black women delivered of infants who weighed greater than or equal to 3000 gm was 4.2 pounds at 9 to 10 weeks' gestation, 14.8 pounds at 11 to 20 weeks, 24.5 pounds at 21 to 30 weeks, and 33.9 pounds at 31 to 40 weeks. Weight gain was highly variable at all gestational ages in both black and white women. Weight gain in both black and white women delivered of infants with weights greater than or equal to 3000 gm was linear at a rate of about 0.66 pounds per week from 8 through 20 weeks' gestation and linear at a rate of 1.06 pounds per week after week 20.

Birth Weight↗
PubMed1991

Safety and immunogenicity of oligosaccharide conjugate Haemophilus influenzae type b (HbOC) vaccine in infancy. The Northern California Kaiser Permanente Vaccine Study Center Pediatrics Group.

The safety and immunogenicity of the HbOC conjugate vaccine have been evaluated in a study population of 61,080 children in the Kaiser Permanente Medical Care Program of Northern California. Half of the population served as controls. The vaccine was given as part of a three-dose regimen in the first year of life with the first dose given between 6 weeks and 6 months of age, a minimum interval of 1 month between doses and with the third dose given by 1 year of age. The vaccine was highly immunogenic with 97% of infants developing 1 microgram/ml or more of anti-polyribosyl phosphate antibody as measured by Farr assay 1 month after completion of the three-dose series and with 71% maintaining this concentration until a booster dose was given at approximately 18 months of age. There were three cases of Haemophilus influenzae type b disease after the first dose of vaccine and two of these children died. However, there was no statistically significant difference between either the incidence of H. influenzae type b disease or the mortality rate in infants after one dose of HbOC vaccine when compared with H. influenzae type b disease incidence and mortality in unvaccinated children of the same age. The rate of sudden infant death syndrome following HbOC vaccine was lower than that observed within the Kaiser Permanente Medical Care Program as a whole or in the three counties in which sudden infant death syndrome surveillance was tabulated. Immediate local and systemic reactions were evaluated by telephone interviews of 6887 infants within 72 hours of vaccine.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Bacterial↗
PubMed1991

An outcome evaluation of the content and quality of prenatal care.

Linkage of measures of the adequacy, content, and quality of prenatal care with pregnancy outcome is a long-standing research challenge. We attempted to improve on prior studies by developing a measure of prenatal care that encompasses the specific items thought to mediate its relationship with birthweight and by then examining the association of this measure with birthweight. An eight-item index of prenatal care was used to abstract information from the medical records of 63 white and 56 black women who gave birth to low-birthweight (less than 2500 g) infants and 61 white and 101 black women who gave birth to normal-weight (3000 + g) infants in 1987 at two Kaiser Permanente facilities. In univariate analyses the mean values for the index were higher in controls than in cases for both black and white women, but the difference was statistically significant only for blacks. In multivariate analysis the index was not significantly associated with the risk of low birthweight for whites or blacks. Prenatal care was extremely homogeneous in this population, which compromised the evaluation of the index as a correlate of low birthweight. We believe that this is a promising method for assessing the content of prenatal care and studying the association between content and outcome of care.

Black or African American↗
PubMed1991

Mailed dietary surveys: response rates, error rates, and the effect of omitted food items on nutrient values.

Mailed surveys may be a cost-effective way to collect dietary information in large populations. We sent a brief quantified food frequency survey to a random sample of 2,000 prepaid health plan members between the ages of 20 and 65 years for two consecutive years. Logistic regression was used to predict the probability of: (1) responding to the questionnaire, (2) completing all 60 items in the questionnaire correctly so that all information could be used (responding entirely correctly), and (3) completing all 60 items in the questionnaire incorrectly so that no information was usable (responding entirely incorrectly). In a follow-up survey of a subsample of respondents, Spearman correlation coefficients were used to compare nutrient intakes calculated from questionnaires that had omitted data with those from the same questionnaires after the missing information was completed by telephone interview. About 50% of all persons surveyed returned the questionnaire. Response rates were highest among persons who had taken a voluntary multiphasic health examination, among women, and among older persons. Only 22.9% of the respondents in year 1 and 27.7% of the respondents in year 2 responded entirely correctly; a small percentage of respondents (12.1%) omitted more than 10 food items. Responding entirely correctly was inversely related to age and related to race. Most correlations between nutrient intakes calculated from questionnaires with omitted data and those from the same questionnaire subsequently completed by telephone interview were greater than 0.90 and increased as the number of omitted items decreased. If a relatively low overall response rate is acceptable, food frequencies collected through the mail can be an effective way to gather dietary information.

Adult↗
PubMed1990

Micronucleated erythrocytes as an index of cytogenetic damage in humans: demographic and dietary factors associated with micronucleated erythrocytes in splenectomized subjects.

Erythrocytes containing micronuclei serve as an indicator of genotoxic exposure in splenectomized individuals. Micronucleated erythrocytes, derived from cytogenetically damaged RBC precursors, are not selectively removed from peripheral blood in individuals who lack splenic function. The relationship between micronucleated cell frequencies and demographic, environmental, and dietary factors was examined in 44 subjects with previous splenectomy due to trauma. Their micronucleated cell counts fit a log-normal distribution, with geometric means of 3.3 micronucleus-containing cells/1000 reticulocytes and 2.7/1000 normochromatic erythrocytes. A multiple regression analysis showed that drinking five cups of coffee or tea/day (relative to none) was associated with an approximately 2-fold higher frequency of micronucleated cells. Weaker statistical associations were also noted with micronucleus frequency and the consumption of calcium supplements (associated with a higher frequency) and vitamins A, C, or E (lower frequency). An apparent trend of higher micronucleus counts with age was attenuated when other factors were considered in the regression. Cigarette smoking and decaffeinated coffee consumption were among the factors not associated with elevated micronucleated cell frequencies. Because the occurrence of micronuclei in reticulocytes reflects cytotoxic exposures within the past 3-8 days, it may be possible to test directly the relationship of these factors to micronucleus formation through intervention studies.

Chromosome Aberrations↗
PubMed1990

Exposure to barbiturates in utero and during childhood risk of intracranial and spinal cord tumors.

Barbiturate exposure during childhood was assessed from medical records of 237 children with intracranial and spinal cord tumors and 474 matched controls in a prepaid health plan. In utero exposure was also examined in a subset of 86 "cases" and 172 controls whose mothers were health plan members during pregnancy. No association of in utero exposure to barbiturates was found [odds ratio (O.R.) = 0.96, 95% confidence interval (C.I.) = 0.47, 1.94]. An association was noted for barbiturate use during childhood (O.R. = 1.80, 95% C.I. = 1.18, 2.74) but was reduced (O.R. = 1.41, 95% C.I. = 0.89, 2.21) when history of epilepsy was taken into account and was no longer significant. An apparent dose-response effect disappeared after adjustment for a history of epilepsy. Although barbiturate use for epilepsy due to preexisting brain tumors clearly explains some of the observed association, the small, residual risk prevents us from ruling out a possible carcinogenic effect of barbiturates. Further study of cohorts of adult as well as childhood users of barbiturates and other anticonvulsants is recommended.

Adolescent↗
PubMed1990

Alcohol consumption and breast cancer.

Epidemiologic studies of the relationship of alcohol consumption and breast cancer are generally in support of a direct association, although they are not entirely consistent. Studies supporting this finding have come from many countries around the world and from many investigators working with different study designs and types of populations. Ten of 16 case-control studies, and five of six cohort studies have produced results supporting a positive association. When evaluated together through techniques such as meta-analysis, these studies suggest that there is a 50% increase in breast cancer risk for women who average between one and two drinks per day. All types of alcoholic beverages seem to increase the risk, but there is little agreement between studies on dose-response relationships. No biologic explanation for alcohol's possible role in breast carcinogenesis is yet known, but several hypotheses have been advanced. In the absence of any effective method of primary breast cancer prevention, and because current risk factors explain so little of the incidence of this common cancer, alcohol consumption is of potential importance from both public health and etiologic perspectives. The possible protective effect of moderate alcohol consumption on heart disease should be considered when assessing the risks of this level of consumption on breast cancer.

Alcohol Drinking↗
PubMed1990

Epidemiologic features of treated end-stage renal disease in a large prepaid health plan.

We examined the incidence of treated end-stage renal disease (ESRD) among the two million members of the Kaiser Permanente Medical Care Program of Northern California from 1973 through 1985. The age-adjusted incidence rates rose from 33.9 to 81.7 per million person-years and showed no signs of stabilization. Rates were higher in men than in women and rose with age. Marked upward trends (p less than .001) in the rates of treated ESRD associated with diabetic nephropathy and hypertension were noted.

Adolescent↗
PubMed1990

The cost of acquired immunodeficiency syndrome in northern California. The experience of a large prepaid health plan.

We studied the cost of acquired immunodeficiency syndrome (AIDS) in the Kaiser Permanente Medical Care Program (KPMCP), northern California region. We report the costs of care to the KPMCP and introduce an innovative application of survival methods to cost analysis. From the beginning of the AIDS epidemic in 1981 to the end of June 1987, 866 cases of AIDS were recorded among members of the KPMCP. Estimates of the costs of care of these patients were derived from comprehensive chart reviews of a random sample of 71 patients whose conditions were diagnosed from January 1984 through June 1987. Total mean lifetime costs per patient were $32,816 (median, $28,677), whereas the mean hospital per diem cost was $20,446 per patient. As more care was shifted to outpatient services overtime, overall costs dropped, despite marked increases in the cost of outpatient medications such as zidovudine. The overall estimate of cost compared closely with other estimates of the cost of care in San Francisco, Calif, and it is lower than estimates from elsewhere in the United States, probably because of the low proportion of cases associated with intravenous drug use and the well-developed social support networks available to patients with AIDS in the San Francisco Bay Area.

Acquired Immunodeficiency Syndrome↗