ABSTRACT
Identifying the risk factors of recurrence of a disease is important both for physicians and patients. Analyzing the first recurrence may lead to an inaccurate evaluation of risk factors as it may not reflect the history of disease completely and may result in the loss of some valuable information. This study was aimed to analyze the time up to the recurrent relapses of schizophrenia as well as determining the risk factors that lead to the recurrence of the disease. In this study 159 registered schizophrenia patients at Razi hospital were selected from a longitudinal study. The effect of age, sex, marriage, start of disease, and history of head trauma variables on recurrence of disease was assessed by a frailty model. Data analysis was made on by R 2.14.1. Mean of patients' age was 21.5 +/- 6.6 year. Based on the Gamma frailty model, sex of patients [p=0.045] and history of head trauma [p=0.028] had significant effect on the hazard of recurrent relapses of Schizophrenia. In addition, the correlation of first, second and third times of recurrence was significant [p<0.001]. Based on the dependency between relapses, treatment and follow-up actions are suggested within the first recurrence time