Why do so few HMOs offer Medicare risk plans in rural areas?

Only 17 of the 38 health maintenance organizations (HMOs) that have Medicare risk contracts and offer coverage to commercial clients in rural counties include the rural counties in their Medicare plan service areas. Rural counties in which HMOs offer Medicare coverage have higher average adjusted average per capita costs (AAPCCs), larger populations, and more physicians per capita than rural counties excluded by risk plans. Interviewed plans cite low and erratic AAPCCs, scarcity of potential enrollees, lack of negotiating power with physicians, and adverse selection as drawbacks in rural areas. Proposed changes to the payment methodology would probably lead HMOs to increase their Medicare offerings in urban fringe areas, but not in isolated rural areas.

Prospective payments to hospitals: should emergency admissions have higher rates?

Systematic variation in patient resource use can be a significant problem for a system based on diagnosis-related groups (DRG's) if this variation is not evenly distributed across hospitals. If certain hospitals routinely treat patients who require more services than average under DRG's, the long-run financial viability of these hospitals will be threatened. In this study, the authors examine whether patients who are admitted on an emergency or urgent basis represent an identifiable group of patients whose costs are systematically higher than those of electively admitted patients, controlling for DRG. Alternative approaches for incorporating admission status into a DRG payment system are developed and tested.

State policies and the financing of acquired immunodeficiency syndrome care.

State policies, with respect to the operation of Medicaid programs and the regulation of private health insurance, affect who gets what care, how much is spent, and who ultimately pays. A RAND Corporation study was used to assess States and the District of Columbia in terms of the effects of their Medicaid and health insurance regulations on people with acquired immunodeficiency syndrome and other human immunodeficiency virus-related illnesses. State characteristics are used to explain the individual State policy rankings.

Effects of type of dietary fat on indices of immune status of rabbits.

We have compared the effects of dietary saturated and unsaturated fats of the n-6 and n-3 types on the immune status of male New Zealand white rabbits. Four groups of rabbits (n = 8) were fed purified diets containing one of the following fats (7.6% w/w, 23 kcal%) for 5 mo, hydrogenated soybean oil (HSO); safflower oil (SFO); linseed oil (LSO); or menhaden oil (MHO). In vitro proliferation of peripheral blood lymphocytes (PBL) cultured with T-cell mitogens was significantly higher in the LSO group than in the other three groups, and that in the HSO group was higher than in the MHO and SFO groups which were not different from each other. Proliferation of PBL in response to B-cell mitogens was significantly higher in the LSO group than in the SFO and MHO groups. In vitro proliferation of splenocytes (SPC) from the LSO group was higher than that from the other three groups only when SPC were cultured with T-cell mitogens. Serum antibody levels against bovine serum albumin were significantly higher in the LSO group than in the SFO group after second and third immunizations. Spleen weights, number of SPC or PBL, and delayed-type hypersensitivity were not different among the four dietary groups. Our data show that linseed oil diet enhanced several indices of immune status in rabbits.

The influence of dietary fat on the lipogenic activity and fatty acid composition of rat white adipose tissue.

The in vivo fatty acid synthesis rate, selected enzyme activities and fatty acid composition of rat white adipose tissue from animals fed semisynthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then refed a fat-free (FF) diet for 48 hr. They were then divided into three groups. One group was continued on the FF diet for 48 hr. Another group was fed a diet containing 44% of calories from corn oil (CO). The final group was fed a diet containing 44% of calories from completely hydrogenated soybean oil (HSO). The animals on the FF diet had a marked increase in adipose tissue fatty acid synthesis during the 96-hr feeding period (as measured by 3H incorporation into adipose fatty acids). Addition of either CO or HSO to the diets did not significantly inhibit fatty acid synthesis in dorsal or epididymal adipose tissue. The activities of the enzymes' fatty acid synthetase, ATP-citrate lyase and glucose-6-phosphate dehydrogenase increased on the FF diet and generally were not inhibited significantly by the addition of either fat to the diets. Linoleic acid was the major polyunsaturated fatty acid (ca. 22%) in adipose tissue. Monounsaturated fatty acids (palmitoleic, oleic, cis-vaccenic) made up ca. 38% of the total adipose fatty acids, while saturated fatty acids accounted for about 32% (myristic, palmitic and stearic). White adipose tissue in mature male rats was a major depot for n-3 fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of fat-free, saturated and polyunsaturated fat diets on rat liver and plasma lipids.

The liver and plasma lipids and fatty acid composition of rats fed synthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then refed a high carbohydrate, fat-free diet for 48 hr. They were then divided into three groups and fed for an additional 48 hrs the following: group 1, the fat-free diet; group 2, a diet containing 44% of calories from corn oil; and group 3, a diet containing 44% calories from completely hydrogenated soybean oil. The total lipid concentration of the liver in the animals on the fat-free diet was elevated at 72 and 96 hr. The addition of either saturated or unsaturated fat in the diet at 48 hr prevented this accumulation. The total phospholipid and cholesterol concentrations of the liver were relatively uninfluenced by any diet in this study. Plasma total fatty acid concentration was elevated at 72 hr in the animals on a fat-free diet compared to those fed the stock diet, starved for 48 hr or fed the fat-containing diets. By 96 hr, however, plasma fatty acid concentrations in all groups were similar to those in animals fed only the stock diet. The release of de novo synthesized fatty acids into plasma from the liver was strongly inhibited by dietary fat, either saturated or polyunsaturated. With the fat-free diet there was a significant increase in the saturated and monounsaturated fatty acids in both liver and plasma.(ABSTRACT TRUNCATED AT 250 WORDS)