RESUMEN
The systemic complications of blood donation are the first reasons why patients fail to return for further blood donation. This study was designed to determine the frequency of these complications and their associated risk factors among blood donors in Tehran. Also, we aimed to provide suitable methods to decrease the frequency of these adverse events, thereby eliminating the most important causes of withdrawal, while maintaining the health of the donors. This analytical descriptive cross-sectional study was performed on 554 blood donors who had donated blood from February 2005 through September 2005 in four fixed blood donation bases and four mobile blood collection buses. Each base was considered as a stratum, and a stratified random sampling proportional to size was done to select the donors. Results showed donor reaction rate to be 13.4%, the most common of which were blackout of vision [7%], dizziness [6.3%], fatigue [6.1%] and nausea [1.8%]. There was no significant relationship between the incidence of these complications and type of base blood donation or fasting at the time of blood donation. Logistic Regression analysis showed that sex, condition of blood donor, exercise or walking, duration of donation, and practice to recommendation had significant effects on the odds ratio of systemic complication. Regarding the frequency values derived for the different systemic complications it can be concluded that attention to risk factors of these complications and their control can help encourage donors to become repeated donors as well as to prevent their withdrawal for further blood donation