Z Rajabpoor, S.r Majdzadeh, A Feizzadeh Khorasani, A Motevalian, M Hoseini,
Volume 1, Issue 1 (12-2005)
Abstract
Background and Objective: Road traffic injuries are among the most important causes of death and disability in Iran, and the country has one of the highest prevalence of opioid drug use, especially among drivers. The effect of different situations related to opioid use needs great attention. The purpose of this study was to estimate the effect of driving in the withdrawal phase on the occurrence of traffic accidents leading to injury.
Materials and Methods: This is a Case-Crossover study on injured drivers of crashed motor vehicles in Kerman. Drivers having skipped one habitual drug dose within one hour of the driving session were considered as being in withdrawal. We compared the drivers' situation at the time of accident with their regular driving habits.
Results: Among 75 drivers who had history of regular use of opium, 15 were in withdrawal phase at the time of accident. The relative rate of occurrence of traffic injuries while driving in these circumstances was 2.67 (95% confidence interval: 1.52 - 4.68).
Conclusion: According to these findings we can conclude that habitual opioid users are at greater risk of traffic accidents while driving in withdrawal status this risk is more than two-fold relative to not being in withdrawal status.
M Qorbani, M Yunesian,
Volume 4, Issue 1 (4-2008)
Abstract
The case-crossover design was developed in the early 1990s to study the effects of transient, short-term exposures on the risk of acute events such as myocardial infarction. To estimate relative risk, the exposure frequency during a period just before outcome onset (hazard period) is compared with exposure frequency during control time(s) in that person rather than in a control. One or more "control times" are supplied by each of the cases themselves to control for confounding by constant characteristics and self-confounding between the trigger's acute and chronic effects.
In the analysis of case-crossover studies, exposure frequency in the hazard period is compared with the control period or the individual's usual frequency of exposure. The design has been used frequently for heart diseases, injuries and air pollution epidemiology. This review article looks at published case-crossover studies and is intended to help the reader gain a better understanding of the strengths and limitations of the case-crossover design in studying the epidemiology of injuries and air pollution.
