The Effects of Competition on Variation in the Quality and Cost of Medical Care

We estimate the effects of hospital competition on the level of and the variation in quality of care and hospital expenditures for elderly Medicare beneficiaries with heart attack. We compare competition's effects on more-severely ill patients, whom we assume value quality more highly, to the effects on less-severely ill, low-valuation patients. We find that low-valuation patients in less-competitive markets receive more intensive treatment than in more-competitive markets, but have statistically similar health outcomes. In contrast, high-valuation patients in less-competitive markets receive less intensive treatment than in more-competitive markets, and have significantly worse health outcomes. Since this competition-induced increase in variation in expenditures is, on net, expenditure-decreasing and outcome-beneficial, we conclude that it is welfare-enhancing. These findings are inconsistent with conventional models of vertical differentiation, although they can be accommodated by more recent models.

General Relativistic Electromagnetic Fields of a Slowly Rotating Magnetized Neutron Star. I. Formulation of the equations

We present analytic solutions of Maxwell equations in the internal and external background spacetime of a slowly rotating magnetized neutron star. The star is considered isolated and in vacuum, with a dipolar magnetic field not aligned with the axis of rotation. With respect to a flat spacetime solution, general relativity introduces corrections related both to the monopolar and the dipolar parts of the gravitational field. In particular, we show that in the case of infinite electrical conductivity general relativistic corrections due to the dragging of reference frames are present, but only in the expression for the electric field. In the case of finite electrical conductivity, however, corrections due both to the spacetime curvature and to the dragging of reference frames are shown to be present in the induction equation. These corrections could be relevant for the evolution of the magnetic fields of pulsars and magnetars. The solutions found, while obtained through some simplifying assumption, reflect a rather general physical configuration and could therefore be used in a variety of astrophysical situations.Comment: A few typos corrected; matches the versions in MNRA

Mortality Among Very Low-Birthweight Infants in Hospitals Serving Minority Populations

Objective. We investigated whether the proportion of Black very low-birth-weight (VLBW) infants treated by hospitals is associated with neonatal mortality for Black and White VLBW infants. Methods. We analyzed medical records linked to secondary data sources for 74050 Black and White VLBW infants (501 g to 1500 g) treated by 332 hospitals participating in the Vermont Oxford Network from 1995 to 2000. Hospitals where more than 35% of VLBW infants treated were Black were defined as “minority-serving.” Results. Compared with hospitals where less than 15% of the VLBW infants were Black, minority-serving hospitals had significantly higher risk-adjusted neonatal mortality rates (White infants: odds ratio [OR]=1.30, 95% confidence interval [CI] = 1.09, 1.56; Black infants: OR = 1.29, 95% CI = 1.01, 1.64; Pooled: OR = 1.28, 95% CI=1.10, 1.50). Higher neonatal mortality in minority-serving hospitals was not explained by either hospital or treatment variables. Conclusions. Minority-serving hospitals may provide lower quality of care to VLBW infants compared with other hospitals. Because VLBW Black infants are disproportionately treated by minority-serving hospitals, higher neonatal mortality rates at these hospitals may contribute to racial disparities in infant mortality in the United States