19 research outputs found
A spatio‑temporal model of homicide in El Salvador
This paper examines the spatio-temporal evolution of homicide across the municipalities of El Salvador. It aims at identifying both temporal trends and spatial clusters that may contribute to the formation of time-stable corridors lying behind a historically (recurrent) high homicide rate. The results from this study reveal the presence of significant clusters of high homicide municipalities in the Western part of the country that have remained stable over time, and a process of formation of high homicide clusters in the Eastern region. The results show an increasing homicide trend from 2002 to 2013 with significant municipality-specific differential trends across the country. The data suggests that links may exist between the dynamics of homicide rates, drug trafficking and organized crime
Improving the Prognostic Ability through Better Use of Standard Clinical Data - The Nottingham Prognostic Index as an Example
Background Prognostic factors and prognostic models play a key role in medical
research and patient management. The Nottingham Prognostic Index (NPI) is a
well-established prognostic classification scheme for patients with breast
cancer. In a very simple way, it combines the information from tumor size,
lymph node stage and tumor grade. For the resulting index cutpoints are
proposed to classify it into three to six groups with different prognosis. As
not all prognostic information from the three and other standard factors is
used, we will consider improvement of the prognostic ability using suitable
analysis approaches. Methods and Findings Reanalyzing overall survival data of
1560 patients from a clinical database by using multivariable fractional
polynomials and further modern statistical methods we illustrate suitable
multivariable modelling and methods to derive and assess the prognostic
ability of an index. Using a REMARK type profile we summarize relevant steps
of the analysis. Adding the information from hormonal receptor status and
using the full information from the three NPI components, specifically
concerning the number of positive lymph nodes, an extended NPI with improved
prognostic ability is derived. Conclusions The prognostic ability of even one
of the best established prognostic index in medicine can be improved by using
suitable statistical methodology to extract the full information from standard
clinical data. This extended version of the NPI can serve as a benchmark to
assess the added value of new information, ranging from a new single clinical
marker to a derived index from omics data. An established benchmark would also
help to harmonize the statistical analyses of such studies and protect against
the propagation of many false promises concerning the prognostic value of new
measurements. Statistical methods used are generally available and can be used
for similar analyses in other diseases
The persistence of lifestyles: rates and correlates of homicide in Western Europe from 1960 to 2010
This article analyses rates and correlates of homicide in 15 West European countries from 1960 to 2010. The results show that the levels of homicide in 2010 and the trends in homicide from 1960 to 2010 are not related to any of the traditional demographic and socioeconomic predictors of crime. Homicide victimization rates show an increase from the mid-1960s until the early 1990s, and a decrease since then. Victims of both genders and all group ages follow the same trend, except in the case of infanticide, which decreased during the whole period. These results do not support the hypothesis of a homicide trend driven by the evolution of victimization of young men in public space. The authors propose an explanation based on a lifestyle approach