A Multi-state Piecewise Exponential Model of Hospital Outcomes after Injury

To allow more accurate prediction of hospital length of stay (LOS) after serious injury or illness, a multi-state model is proposed, in which transitions from the hospitalized state to three possible outcome states (home, long-term care, or death) are assumed to follow constant rates for each of a limited number of time periods. This results in a piecewise exponential (PWE) model for each outcome. Transition rates may be affected by time-varying covariates, which can be estimated from a reference database using standard statistical software and Poisson regression. A PWE model combining the three outcomes allows prediction of LOS. Records of 259,941 injured patients from the US Nationwide Inpatient Sample were used to create such a multi-state PWE model with four time periods. Hospital mortality and LOS for patient subgroups were calculated from this model, and time-varying covariate effects were estimated. Early mortality was increased by anatomic injury severity or penetrating mechanism, but these effects diminished with time; age and male sex remained strong predictors of mortality in all time periods. Rates of discharge home decreased steadily with time, while rates of transfer to long-term care peaked at five days. Predicted and observed LOS and mortality were similar for multiple subgroups. Conceptual background and methods of calculation are discussed and demonstrated. Multi-state PWE models may be useful to describe hospital outcomes, especially when many patients are not discharged home.     

Figuring the future in Los(t) Angeles

Abstract

This article examines Los Angeles' symbolic relation to the rest of the US, deriving from its multi-layered political, social, economic, racialized and environmental complexity. Metropolitan Los Angeles has become 'a dystopian symbol of Dickensian inequalities and intractible racial contradictions', according to historian Mike Davis. Rather than representing America's modernity, Los Angeles has come to symbolize 'the collapse of the American Century'. Accordingly this article explores the motives of African American writers in representing Los Angeles as a politically and environmentally disastrous living space and a figure for the state of the nation. The value that black writers place upon and celebrate in the multiple range of urban ethnicities is at odds, not only with the class and racialized political and economic hierarchies of the city which oppresses its black residents but also contrary to contemporary dominant models of American citizenship. The article considers work by Chester Himes, Octavia Butler and Walter Mosley and argues that within and without the borders of the US, labels like 'minority' or 'ethnic' literature ghettoize, marginalize and minimize its significance. Yet the work of these authors currently carries the weight of the search for a more ethical and moral sense of responsibility for the state of a nation skidding down the path of increasing inhumanity, injustice and disregard, not only for the majority of its own population but for the majority of the residents of this planet. These works are significant acts of dissent from the perpetuation of injustice in contemporary politics, from the increasing extremes of wealth and poverty, and from the parasitic relation of the US to the environment.