Determination of the informativeness of the criteria for diagnosing timing of bruising by the Cox model

Abstract

Establishing the age of damage is one of the most important issues that is solved during the forensic examination. The purpose of the work was to determine of the informativeness of the criteria for diagnosing timing of bruising by the Cox model. In research, which consists of 2291 bruises, described in 523 victims, 7 diagnostic features were described: gender, age, shape and size of bruising, its location, color, and the presence of edema of the skin. The informative nature of these features was determined by the Cox model and the Ordinal logit model. The victims sex does not affect the development of bruising. Age slows down this development. Bruises that are located on the upper limbs heal faster than other localization, and located on the hips and buttocks - slower. The rate of healing of bruises reliably depends on its area: with an increase in area by 1%, the time of healing of bruising slows by 1%. The process of healing of bruises reliably depends on its color: the longer the bruise exist, the slower the rate of change of one color to another. The presence of swelling of the skin depends on its age and characterizes the initial stages of its development. Conclusions: of the 7 diagnostic signs to establish the age of bruises - 6 have an informative value, and most among them have their color, on condition that it is divided into 6 parameters (color groups). The dynamics of color change affects the persons age. On the upper limbs, the bruising heals faster, on the hips and buttocks - slower. The healing rate on the straight line depends on its area, with the increase of the area - the healing rate slows down. The presence of swelling of the skin is characteristic in the early stages of bruising, which increases the reliability of the diagnosis in these terms.