Issues relating to early detection and diagnosis of breast cancer in New Zealand general practice.

AIM: This study describes current practice in New Zealand general practice with emphasis on identifying problem areas in the early detection of breast cancer. The study is focused on women outside the age group for the New Zealand breast screening programme (50-64 years). METHOD: Thirty selected general practitioners throughout New Zealand were interviewed in depth to identify the key issues relating to the early detection and diagnosis of breast cancer in the primary care setting. Attitudes to key issues were quantified in a later postal survey of 656 general practitioners randomly sampled from the RNZCGP database. RESULTS: The response rate to the quantitative study was 82%. General practitioners were generally well informed about risk factors for breast cancer and the relative sensitivity and specificity of screening and diagnostic tools. Diagnosis and management were influenced by the limitations of screening and diagnostic tools, as well as access to, and confidence in, services. The appropriate level of investigation and follow-up for young women was an area of uncertainty. CONCLUSION: The study provided data to inform guideline development and a baseline measure of current practice against which the impact of the implementation of guidelines could be measured.

Poverty and death in the United States.

The authors conducted a survival analysis to determine the effect of poverty on mortality in a national sample of blacks and whites, 25 to 74 years of age (the first National Health and Nutrition Examination Survey (NHANES-1) and NHANES-1 Epidemiologic Follow up Study). They estimated the proportion of mortality associated with poverty during 1971-1984 and in 1991 by calculating population attributable risk and assessed confounding by major known risk factors (e.g., smoking, cholesterol levels, and physical inactivity). In 1973, 6.0 percent of U.S. mortality among black and white persons 25 to 74 years of age was attributable to poverty; in 1991, the proportion was 5.9 percent. In 1991, rates of mortality attributable to poverty were lowest for white women, 2.2 times as high for white men, 8.6 times as high for black men, and 3.6 times as high for black women. Adjustment for all these potential confounders combined had little effect on the hazard ratio among men, but reduced the effect of poverty on mortality among women by 42 percent. The proportion of mortality attributable to poverty among U.S. black and white adults has changed only minimally in recent decades. The effect of poverty on mortality must be largely explained by conditions other than commonly recognized risk factors.

Identifying ancestry: The reliability of ancestral identification in the United States by self, proxy, interviewer, and funeral director.

We examined consistency in the classification of ancestry by self, proxy, interviewer, and funeral director (on a death certificate) in a sample of the U.S. population--the First National Health and Nutrition Examination Survey and Epidemiologic Follow-up. Among study subjects for whom comparable ethnic identity options were available at both interviews, 58% of subjects specified the same identity at two times. Persons who specified four different ethnic backgrounds were 3.4 times as likely to change their identity over time as persons specifying only one background. Self-classification of ancestry at initial interview was consistent with proxy reports at follow-up for 55% of subjects for whom proxy information was available. Comparison of the self-classification of ancestry with the classification of race by interviewers and by funeral directors indicates high consistency for Whites and Blacks and low consistency for American Indians. The "measurement" of ancestry (that is, race or ethnicity) is critical to the understanding and elimination of differences in health status among racial/ethnic populations, but the low reliability of these measures over time and across observers complicates the analysis and interpretation of health statistics by ancestry, particularly for populations other than White or Black.

Poverty and death in the United States--1973 and 1991.

We conducted a survival analysis to determine the effect of poverty on mortality in a national sample of blacks and whites 25-74 years of age (in the First National Health and Nutrition Examination Survey and National Health Examination Follow-up Survey). We estimated the proportion of mortality associated with poverty from 1973 through 1984 and in 1991 by calculating the population attributable risk. We assessed confounding by major known risk factors, such as smoking, serum total cholesterol, and inactivity. In 1973, 16.1% of U.S. mortality among black and white persons 25-74 years of age was attributable to poverty; in 1991, the proportion increased to 17.7%. In 1991, the population attributable risk of poverty on mortality was lowest for white women, 1.7 times higher for white men, 2.6 times higher for black women, and 3.6 times higher for black men. Potential confounders explained 40% of the effect of poverty on mortality among women. The proportion of mortality attributable to poverty among U.S. black and white adults has increased in recent decades and is comparable to that attributable to cigarette smoking. The effect of poverty on mortality must be explained by conditions other than commonly recognized risk factors.

A community-wide outbreak of hepatitis A: risk factors for infection among homosexual and bisexual men.

PURPOSE: To assess risk factors for hepatitis A infection among homosexual and bisexual men during a community-wide outbreak of hepatitis A in New York City. PATIENTS AND METHODS: Twenty-five homosexual and bisexual men, 20 to 49 years of age with hepatitis A identified from health department surveillance data (cases) were compared with 42 homosexual and bisexual men of similar age distribution who were seronegative for hepatitis A virus and identified from private physician offices (controls). Odds ratio (OR) were determined for acute hepatitis A infection according to demographics, numbers of sexual partners, frequency of specific sexual behaviors, and self-reported human immunodeficiency virus status. RESULTS: Cases had more anonymous sex partners (0 to 1 partner versus > 1 partner) than controls during the 6 weeks before illness onset (OR = 4.4, 95% confidence interval [CI] 1.4 to 14.4). Cases were more likely than controls to have engaged in group sex (OR = 3.8, 95% CI 1.1 to 12.6). Among specific sexual behaviors examined, oral-anal intercourse (oral role) and digital-rectal intercourse (digital role) with anonymous sex partners were more commonly reported by cases than controls (OR = 9.7, 95% CI 1.2 to 78.7 and OR = 2.6, 95% CI 1.0 to 7.4, respectively). Multivariate analysis showed that > 1 anonymous sex partner, group sex, oral-anal intercourse, and digital-rectal intercourse were associated with illness in models controlling for duration of sexual activity. Because these variables were highly correlated, independent risk could not be evaluated in a single model. CONCLUSIONS: Hepatitis A infection among homosexual and bisexual men is associated with oral-anal and digital-rectal intercourse, as well as with increasing numbers of anonymous sex partners and group sex. These findings reinforce the importance of developing educational activities for homosexual and bisexual men that focus on risk reduction for hepatitis A as well as other sexually transmitted disease spread via the fecal-oral route.

Risk factors associated with severe measles in Puerto Rico.

From January to April, 1990, 695 measles cases were reported to the Puerto Rico Health Department; there were 12 measles-associated deaths (case fatality ratio, 17/1000), more than in any year since 1967. We conducted a case-control study of risk factors for severe measles. We identified 16 children (ages 5 to 34 months) with severe measles and selected children with nonsevere measles as controls (39 hospitalized and 38 nonhospitalized). Controls were frequency matched to severe measles cases by region of residence. One case and two controls had been vaccinated. An underlying illness was present in 50% of cases and 16% of nonhospitalized controls (Mantel-Haenszel weighted odds ratio 5.3; 95% confidence interval 1.4, 20.2). In a multivariate analysis cases were significantly more likely than hospitalized controls to be from families with an annual income of < $5000 (odds ratio (OR), 26.9), to have a mother without a high school degree (OR 11.1), to be anemic (hemoglobin < 10 g/dl) (OR 15.9) and have an underlying illness (OR 18.3). During measles outbreaks preventing severe illness requires aggressive control measures and strategies to increase vaccine coverage of children with underlying illnesses and of low socioeconomic status.

Application of an isolated heart model to investigate blood-oxygen delivery.

To avoid the compensatory hemodynamic responses, which have limited interpretation of hemoglobin-oxygen affinity modifications in animal experimentation, an isolated blood-perfused rabbit heart model providing metabolic, functional, and vectorcardiographic measurements has been developed. Fixed-flow perfusions of unchanged or affinity-modified red blood cell suspensions were carried out to assess the benefits of high affinity during hypoxic hypoxia and of low affinity during posthypoxic recovery. Using fully saturated suspensions, the influence of affinity level during restricted flow and reperfusion was also studied. Higher myocardial oxygen consumption (MVO2) was associated with high-affinity blood during mild hypoxia and low-affinity blood during posthypoxic recovery. At low flows, heart rate and MVO2 tended to be lower in high-affinity perfusions, and to recover more completely during low-affinity reperfusions. Ventricular function, vectorcardiographic patterns, and lactate levels were affected by hypoxia and ischemia, but not by level of affinity. The relevance of these observations to the therapeutic potential of hemoglobin-oxygen affinity modification is discussed.

Effects of methylprednisolone on the physical properties of the human red cell.

Prompted by evidence suggesting preserved red cell deformability in cardiac surgical patients pretreated with pharmacologic dosages of methylprednisolone, we performed in vitro experiments to examine the ability of similar levels of methylprednisolone and hydrocortisone to modify erythrocyte membrane changes produced by metabolic depletion or membrane-active compounds. Variables measured included cell morphology, blood biscosity, membrane deformability, osmotic fragility, red cell cholesterol, and glycolytic intermediates. In incubated samples, methylprednisolone partially prevented the transition of discs to echinocytes, the rise in whole blood viscosity, the decrease in membrane deformability, and the loss of red cell cholesterol which accompany ATP depletion, but it had no apparent effect on red cell glycolysis. The drug also inhibited esterification of cholesterol in cell-free serum. In unimcubated samples to which lysolecithin was added, methylprednisolone partially prevented and reversed morphologic and rheologic responses without affecting membrane cholesterol. Hydrocortisone demonstrated similar properties. Possible mechanisms for these actions are discussed. The concept is advanced that preserved blood fluidity may contribute to the beneficial responses to these drugs in certain clinical conditions.

A pH-dependent macroglobulin gel.

Plasma from a patient with Waldenstrom's macroglobulinemia was observed to gel upon exposure to room air, yet to remain in solution indefinitely at 4 degrees C if sealed. Three studies were carried out which showed this change not to be due primarily to decreases in carbon dioxide tension or temperature, but to variations in the concentration of hydrogen ions within or just above physiologic levels. In purified material (IgM) a marked increase in viscosity occurred between pH 7.5 and 8.0, followed by precipitation between pH 8.0 and 9.7, and by reversible dissolution between pH 9.7 and 10.0. The analytical and clinical consequences of these solubility changes are discussed.