The Correlation between the Color Changes of Contusions and the Time Period after Injuries in Thai Populations

Introduction: The color changes of contusions is related to the aging of injuries, which is important in medico-legal aspects. To determine the correlation between the color changes of contusions and the time period after injuries in Thai populations. Method: A cross-sectional study of 400 contusions from 199 Thai healthy patients who had blunt injuries and knew the certain time of injuries was conducted. The colors of contusions were evaluated by visual assessment. The patients’ data including age, sex, size, body area of contusions, type of weapons used, and the time period after injuries were recorded. The data were analyzed by descriptive statistics, Kruskal-Wallis H Test, Mann-Whitney U test with Bonferroni correction for multiple comparisons, and logistic regression analysis. Results: The correlation between the color changes of contusion and the time period after injuries was statistically significant (p < 0.001). The average times for each color in contusions presented at the visiting time were 24, 48, 60, and 84 hours for red, purple, green, and yellow color, respectively. The minimum time that yellow color could be noticeable was 18 hours. Discussion and Conclusion: Yellow color was the key finding for the dating of contusions and should be determined in the examination of contusions.