Increased diagnosis of primary aldosteronism, including surgically correctable forms, in centers from five continents

Primary aldosteronism (PA) is a common form of endocrine hypertension previously believed to account for less than 1% of hypertensive patients. Hypokalemia was considered a prerequisite for pursuing diagnostic tests for PA. Recent studies applying the plasma aldosterone/plasma renin activity ratio (ARR) as a screening test have reported a higher prevalence. This study is a retrospective evaluation of the diagnosis of PA from clinical centers in five continents before and after the widespread use of the ARR as a screening test. The application of this strategy to a greater number of hypertensives led to a 5- to 15-fold increase in the identification of patients affected by PA. Only a small proportion of patients ( between 9 and 37%) were hypokalemic. The annual detection rate of aldosterone-producing adenoma (APA) increased in all centers ( by 1.3-6.3 times) after the wide application of ARR. Aldosterone-producing adenomas constituted a much higher proportion of patients with PA in the four centers that employed adrenal venous sampling ( 28 - 50%) than in the center that did not (9%). In conclusion, the wide use of the ARR as a screening test in hypertensive patients led to a marked increase in the detection rate of PA. Copyright © 2004 by The Endocrine Society

Identifying health centers in Honduras infested with Rhodnius prolixus using the seroprevalence of Chagas disease in children younger than 13 years

The objective of this study is to determine if a Chagas disease protocol starting with a serological survey is as reliable at identifying insect-infested areas as one using the gold standard entomological survey. The study found that health center areas infested with Rhodnius prolixus were identified using a threshold seroprevalence of 0.1%. The serological survey took half the time and was 30% less expensive than the entomological survey. Developing countries with limited resources may find this strategy useful in combating Chagas disease. This strategy also identifies seropositive children, which facilitates their treatment.

A rough cluster analysis of shopping orientation data

This paper describes the application of a new technique, rough clustering, to the problem of market segmentation. Rough clustering produces different solutions to k-means analysis because of the possibility of multiple cluster membership of objects. Traditional clustering methods generate extensional descriptions of groups, that show which objects are members of each cluster. Clustering techniques based on rough sets theory generate intensional descriptions, which outline the main characteristics of each cluster. In this study, a rough cluster analysis was conducted on a sample of 437 responses from a larger study of the relationship between shopping orientation (the general predisposition of consumers toward the act of shopping) and intention to purchase products via the Internet. The cluster analysis was based on five measures of shopping orientation: enjoyment, personalization, convenience, loyalty, and price. The rough clusters obtained provide interpretations of different shopping orientations present in the data without the restriction of attempting to fit each object into only one segment. Such descriptions can be an aid to marketers attempting to identify potential segments of consumers.