Harvard Central Administration and University Research Centers

To gain insight into the possible consequences of prospective payment for university hospitals, we studied 2025 admissions to the faculty and community services of a university hospital, measuring differences in case mix, costs, and mortality in the hospital. The faculty service had more of the patients with costly diagnoses, but even after adjustment for diagnosis-related groups (DRGs), costs were 11 per cent higher on the faculty service (95 per cent confidence limits, 4 to 18 per cent). The percentage differential was greatest for diagnostic costs. The differential was particularly large — 70 per cent (95 per cent confidence limits, 33 to 107 per cent) — for patients with a predicted probability of death of 0.25 or greater. The in-hospital mortality rate was significantly lower on the faculty service after adjustment for case mix and patient characteristics (P<0.05); the difference was particularly large for patients in the high-death-risk category. Comparision of a matched sample of 51 pairs of admissions from the high-death-risk category confirmed the above results with respect to costs and in-hospital mortality, but follow-up revealed that the survival rates were equal for the two services at nine months after discharge. The effect of prospective payment on the cost of care will be closely watched; we conclude that it will also be important to monitor the effect on outcomes, including hospital mortality rates.

Antibiotic use is often blamed for increases in the prevalence of infections due to antibiotic-resistant bacteria. This paper clarifies the effects of antibiotic exposure on bacterial antibiotic resistance by developing models that describe the growth of competing bacterial strains whose antibiotic sensitivities differ. The analysis generalizes logistic growth models to include first-order growth parameters that are arbitrary functions of antibiotic levels. It derives closed-form solutions for population size, composition, and average antibiotic sensitivities as functions of antibiotic exposure. Strategies to minimize the bacterial population size are analyzed in the context of the model. These heuristic models explore in formal terms the population dynamics thought to underlie resistance development.

The purpose of this article is twofold: first, to present the strategic advantages of focused over omnibus tests of statistical significance in counseling research and, second, to demonstrate the utility of interpreting the magnitude of the effect as a way of assessing practical significance (i.c., in addition to computing p levels). Simple procedures are given for computing effect size using the product-moment r in the context of focused significance testing. We show that recasting the effect size into a binomial display is a convenient way of revealing the practical significance of r in terms of whatever equivalency measure is deemed appropriate (e.g., improvement rate, success rate, survival rate).

Antibiotic use is thought to promote bacterial antibiotic resistance by selectively inhibiting the growth of sensitive strains. This study investigates the relation between antibiotic use and the propagation of antibiotic-resistant hospital-acquired infections due to gram-negative bacteria in a population of hospitalized patients. It treats infection spread and hospital mortality as a Markov process, in which the transition probabilities are logistic functions of a set of personal and hospital characteristics. Data from a university hospital are used to derive the parameters of the model.

In the evolution of speech, the censure of mispronunciations can cause them to abate, and thereby reinforce the prevailing norm. Conversely, widespread and longlasting mispronunciation can amend the norm. In the former case we see the reflexive self-stabilization of language norms; in the latter, the reflexive subversion of the norms. This essay proposes a general model of the reflexive stability and change of norms, and applies it to language norms; elsewhere the author applies the same analysis to legal norms. The need traditionally filled by a priori norms is filled by slow-changing, "constitutive a posteriori" norms.

The majority of patients with coronary artery disease do not fall into the well defined populations from randomized clinical trials. Observational databases contain a rich source of information that could be used by practicing physicians to evaluate treatment alternatives for their patients. We describe a computer system, the CABG Kibitzer, which uses an integrated approach to evaluate the treatment alternatives for CAD patients. We combine a statistical multivariate model for calculating survival advantages with DA techniques for assessing patient preferences and sensitivity analysis, to create one tool that physicians find easy to use in daily clinical practice. The development of tools of this kind is a necessary step in making the data of outcome studies accessible to practicing physicians.

The first full-length study of self-reference and paradox in law, this book will intrigue and instruct anyone interested in law, logic, philosophy, or political theory. History shows that self-amendment - for example, the use of a constitution's amending clause to amend itself - is commonplace; legal analysis shows it to be lawful, even if (as some logicians have alleged) it is self-contradictory; and philosophical analysis shows it to be foundational for legality. The lawfulness of self-amendment, therefore, sheds important light on legal reasoning and rationality, and shows that we no longer need accept the immutability of any level of law.