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OBJECTIVE We examined the relationship between survival and time in the emergency department (ED) before laparotomy for hypotensive patients bleeding from abdominal injuries. METHODS Patients in the Pennsylvania Trauma Systems Foundation trauma registry with isolated abdominal vascular, solid organ, or wall injuries grade 3 to 6 and hypotension were(More)
  • D Fife, C Mode
  • 1992
We sought to track recent changes in AIDS incidence and prevalence in the city of Philadelphia (PA, U.S.A.) using morbidity and mortality data reported to the health department. We stratified the data by the mean per capita income in census tracts where people with AIDS resided. Estimates made without adjustment for the time lag between events and their(More)
A case has made for the use of Monte Carlo simulation methods when the incorporation of mutation and natural selection into Wright-Fisher gametic sampling models renders then intractable from the standpoint of classical mathematical analysis. The paper has been organized around five themes. Among these themes was that of scientific openness and a clear(More)
Use of the final size distribution of minor outbreaks for the estimation of the reproduction numbers of supercritical epidemic processes has yet to be considered. We used a branching process model to derive the final size distribution of minor outbreaks, assuming a reproduction number above unity, and applying the method to final size data for pneumonic(More)
In many studies of longevity in experimental animals, sample sizes are small enough to warrant the use of statistical tests of significance in making judgments of scientific interest. Illustrated in this paper is a nonparametric test procedure for deciding on the statistical significance of observed differences in two empirical survival functions. This(More)
  • D Fife, C Mode
  • 1992
Since 1987, the annual increases of AIDS incidence among homosexual and bisexual men have slowed but the increases among other risk groups have continued unabated. Although indirect evidence suggests the incidence change is related to medical care for HIV disease delaying the onset of AIDS, other explanations are also possible. To examine the incidence(More)
The goodnesses of fit over the entire life span of four models of mortality are compared using life tables from Australia and the United States. The results indicate that the five-parameter Siler model fits considerably better than the more complex eight-parameter Heligman-Pollard and Mode-Busby models. On the other hand, the ten-parameter model proposed by(More)
A problem of importance in modelling epidemics of sexually transmitted diseases is the development of mathematical structures accommodating sexual and other contacts among members of a population. Because these models may be complex, it is often necessary to use computer intensive methods in their analysis, which raises questions on the design of computer(More)